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Modular Construction potential advantages and common challenges | Masoud Veiskarami
Modular construction and overview on its
potential advantages and constraints in the
project management perspective
Author
Masoud Veiskarami
Director
Pujadas Alvarez Pablo
Masters degree in
Structural and Construction Engineering
Barcelona September 2020
EPC - Department of Project and Construction Engineering
MA
STER
FIN
AL
THES
IS
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Masterrsquos Degree
Title
Author
Tutor
Speciality
Department
Date
PUJADAS AacuteLVAREZ PABLO
-
September 2020
Structural and Construction Engineering
Modular construction and overview on its potential advantages
and constraints in the project management perspective
MASOUD VEISKARAMI
EPC - Department of Project and Construction Engineering
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Dedication
To my brother Milad one of the best executive civil engineers that I have ever seen who was and will be my role model and inspiration in construction world
دنیای در من بخش الهام و الگو که ام دیده تاکنون که اجرایی عمران مهندسین بهترین از یکی میلاد برادرم به تقدیمبود خواهد و بوده ساز و ساخت
To my parents Professor Kiomars VeisKarami who is my inspiration to pursuit post-education to be an ideal professor like him Ashraf Ahmadi who cherished and supported me all the way I am thankful for all your favours
استاد یک تا است عالی تحصیلات پیگیری برای من بخش الهام که کرمی ویس کیومرث پروفسور مادرم و پدر هب شما لطف از کرد حمایت من از و داشت گرامی مرا زندگی طول تمام در که احمدی اشرف باشم او مانند آل ایده
سپاسگزارم
To dear my friends and classmates Ali Sasani loveable Sofia and genius Junior who always were next to me and will be in my heart
من کنار در همیشه که عزیز جونیور و داشتنی دوست وفیاس ساسانی علی عزیزم های همکلاسی و دوستان برایبود خواهند من قلب در و بودند
To my valuable professors specially Professor Pablo Alvarez Pujadas who guided me to direction that helped me to discover a new perspective of civil engineering that I always was looking for
A mis valiosos profesores en especial al profesor Pablo Alvarez Pujadas quien me guioacute
hacia una direccioacuten que me ayudoacute a descubrir una nueva perspectiva de la ingenieriacutea
civil que siempre estuve buscando
To my language teachers Mr Roozbeh Kargar who made me able to write this dissertation in the most academic way without any obstacles Ms Shafie and Ms Ismaili who shared their knowledge of Spanish to help me through the courses to achieve great marks and improve my knowledge
هیچ بدون روش ترین اکادمیک به را نامه پایان این بتوانم من شد باعث که کارگر روزبه استاد من زبان اساتید به به را خود اسپانیایی زبان دانش که اسماعیلی خانم سرکار و یشفیع خانم سرکار محترم اساتید بنویسم مانعی
بهبود را خود دانش و آورم بدست را عالی نمرات تا کنند کمک من به آموزشی های دوره در تا گذاشتند اشتراکبخشم
ایرانی باد زنده ایران باد زنده
28092020
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Abstract
During past century construction industry is suffering from a poor productivity rate in
comparison with the other industries To solve this problem the concept of industrialization in
construction was introduced which Modular construction is one of its methods with a not short
history However during past decade had changed its nature to be used for longer lifetime as
permanent uses
The purpose of this study is to identify the possible advantages and investigate on common
challenges related to modular construction industry in a project management perspective and intend
to find adequate solution for them The methodology of this study is a combination of quantitative
and qualitative based approaches
A multi-criterion decision-making software (MIVES) was used to measure the functionality of
advantages and their effect on final decision to use ether three modular alternatives (Steel timber
and concrete) or a traditional reinforced concrete method for building a residential project The results
showed that despite few poor performances in two environmental criteria (CO2 emission amount and
Embodied energy used during construction) in general all three modular alternatives had overcome
traditional option in every requirement where prefabricated timber modular method became the
most sustainable alternative This result can confirm the positive effect of modular construction
advantages and show its superior nature over conventional construction
In addition a qualitative online survey form was sent to modular players to confirm the
identified benefits discussion about common challenges and receive recommendations and solutions
to solve them The responds were collected from five companies with the average of 20 years of
experience in modular construction which illustrated that the advantages can be achieved in real
projects as well as the literature review and study cases on decision making process identified
On the other hand there are challenges remaining without resolution such as Lack of
partnership among participants of project conflicts by local codding in use of automation wrong
perceptions of market etc
The possible solutions could be creating an international code for modular products
advertisement on potential advantages of modular method in publicmarket updating the contract
condition and most important of all improving the cooperation between scientific investigators and
off-site industry to motivate and provide the researchers with more real data to prevent contrasts in
hypothesises and find more innovative solutions1
Keywords Sustainability Modular construction Embodied energy Prefabrication Lifecycle assessment (LCA) Building information modelling (BIM) MIVES Productivity rate Standardization
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table of Contents Table of Contents 2
1 Introduction 1
Motivations 1
Orientation of previous studies 1
Gap of knowledge 1
Objectives of the study 2
Survey among the professionals in the modular industry by Online Form 2
Decision-making among three modular methods and conventional option by MIVES 2
Limitations 2
Lack of existence of references related to the subject 2
Non-accessible information from companies and scientific articles 2
Obstacles caused by global lockdown during covid-19 pandemic 2
Organization of the thesis 3
2 State of the art 4
Productivity problem in construction industry 4
Status of productivity rate of construction industry among other industries 4
Reasons of poor productivity 6
Solutions for improvement 7
Brief on modular construction 10
History of modular construction 10
Types of modular product 15
Module architectural types 15
Module structure types 22
Types of modular buildings based on operation period 27
Common uses of modular buildings in the market 27
Construction phases 28
Literature review on possible advantages 31
Scheduling benefits 31
Economic benefits 34
Environmental Benefits 36
Health and security benefits 38
Social-Laboral benefits 39
Modular Construction role in COIVD-19 Pandemic 40
Review on common challenges 41
Initial costs 41
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Architectural challenges 43
Transportation challenges 44
Wrong perceptions among public and real estate market 45
Integration of advanced software 46
Redefining the contracts 46
Supply chain-transportation-onsite assembly management errors 47
3 Common challenges in modular construction industry by a survey 48
Methodology 48
Objective 48
Role of the researcher 48
Ethical considerations 48
Survey setting 48
Development of questionnaire 49
Participant profile 50
Experience amp professions 50
Data collection 51
General information 51
Economic issues 52
Environmental status 52
Social Benefits 53
Initial costs 54
Design limitations 55
Transportation Limitations 55
Project management challenges 56
Social challenges 57
Data analysis amp conclusions 57
Advantages 57
Challenges discussion 58
4 Decision making based on potential advantages among three modular alternatives and
conventional construction method in a project by MIVES software 60
Methodology 60
Objective 60
What is MIVES 60
Data collection process 60
Case Study references 60
Input data 65
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Final indicators 69
Weights 73
Data analysis 76
Indicators Values 76
Criteria Values 77
Requirement Values 81
Sustainability Values (Final decision) 83
5 Conclusions 84
Decision making process 84
Conclusions and discussion 84
ECONOMIC ndash TIME discussion 84
ENVIRONMENTAL discussion 84
SAFETY AND SOCIAL dominance by modular methods 85
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES 85
Effective external factors on decision 86
Future studies 86
Decision making study on two real projects with the input data of professional
modular and traditional constructors 86
Technological studies about the production line of a modular off-site plant by factory
and on-site visits 86
A survey about challenges in modular construction and its possible solutions to find
adequate solutions 86
Recommendations 87
Cooperation between industrial players and scientific researchers in offsite
construction 87
Education about industrialization in construction and its alternatives 87
Establishing international and regional adequate codes 87
Synchronizing the contract conditions with modular construction conditions 87
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc 88
Changes in financial strategies and adapting them with off-site construction nature 88
6 References 89
Anexo 1 95
Anexo 2 102
1 Survey Q amp A 102
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study 4
Figure 2 2 - UK productivity status (Office for National Statistics -ONS) 5
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS) 5
Figure 2 4 - Value added comparison among industries (ennovacom) 6
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom) 6
Figure 2 6 - Fragmentations between construction industry players and their various productivity
rates (McKinsey 2019) 7
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom) 8
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom) 9
Figure 2 9 - Digital construction organization (wwwbimcommunitycom) 9
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom) 10
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom) 11
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom) 11
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8
meters (modulartch) 12
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau) 13
Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
14
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom) 15
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom) 16
Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom) 17
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom) 17
Figure 2 20 - Production steps of floor cassette to walls and their attachment together
(wwwhowickltdcom) 18
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom) 19
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom) 19
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom) 20
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom) 20
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom) 21
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-
Malec (wmengcom) 21
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo) 22
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
23
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported
module (wwwsteelconstructioninfo) 24
Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the
lower levels (wwwsteelconstructioninfo) 25
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other
metals (vanguardmodularcom) 26
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma
Beton) 26
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction
report MBI 2019) 28
Figure 2 34 - Overlaps of phases in modular construction project 29
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom) 30
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method
(McKinsey amp Company 2019) 31
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom) 33
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom) 33
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes) 34
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom) 34
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk) 35
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images) 36
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site
(wwwcadoltocom) 37
Figure 2 44 - various layers of a module building unit including insulations
(wwwsteelconstructioninfo) 38
Figure 2 45 - Compartment floor at junction with external wall and compartment wall
(wwwsteelconstructioninfo) 39
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use
inside convention centres arenas and temporary structures Image courtesy of HGA and The Boldt
Company (prismpubcom) 40
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The
Boldt Company 40
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction
(archdailycom) 41
Figure 2 49 -Balance between Initial costs and Economical benefits 42
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects
(casasinhauscom) 46
Figure 2 51 - synchronization between supply chain transportation and on-site assembly 47
Figure 3 1 - Online office forms for survey use 49
Figure 3 2 - Questionnaire development 50
Figure 3 3 - Participants motivations to start a modular company 51
Figure 3 4 - Re-use potential 53
Figure 3 5 - Contribution in Covid19 epidemic 53
Figure 3 6 - Post sale services por future clients 54
Figure 3 7 - effective factors in initial investments for start-up companies 54
Figure 3 8 - Lack of knowledge among designers and engineers 55
Figure 3 9 - challenges of using automation in off-site plants 56
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study
(WAHammad 2019) 61
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and
conventional methods (Akbarnezhad 2019) 61
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020) 62
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017) 62
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad
2017) 63
Figure 4 6 - Architectural section of multi-residential building (Aye 2011) 63
Figure 4 7 - Structural elements used in modules (Aye 2011) 64
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012) 64
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES) 65
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM
alternatives 71
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software 74
Figure 4 12 - Possible forms of the value function 75
Figure 4 13 - Value function for total project cost in MIVES 75
Figure 4 14 - Criteria normalized values 77
Figure 4 15 - Project Schedule 78
Figure 4 16 - Waste generation ratios 78
Figure 4 17 - CO2 Emission normalized values 79
Figure 4 18 - Recyclability and re-use potential of alternatives 79
Figure 4 19 - Embodied energy consumption and saving potential by reuse 80
Figure 4 20 - Safety advantage of modular construction over traditional method 80
Figure 4 21 - Social criteria 81
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values
analysed by MIVES 81
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind 82
Figure 4 24 - Modular dominance in safety and social requirements over conventional option 82
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives 83
Figure A1 1 - Injury risks for workers (Hammad 2019) 96
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
96
Figure A1 3 - Co2 amount (Aye 2011) 97
Figure A1 4 - Total project cost (Balasbaneh 2020) 97
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
97
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter) 98
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020) 98
Figure A1 8 - Co2 emission (Aye 2011) 98
Figure A1 9 - Injury risks for workers (Hammad 2019) 100
Figure A1 10 - Noise level (Hammad 2019) 100
Figure A1 11 - Greenhouse gas emission (Aye 2011) 101
Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo) 23
Table 2 2 - Possible benefits in projects scheduling 32
Table 2 3 - Economic benefits in modular method 35
Table 2 4 - Environmental Benefits 37
Table 2 5 - Health and safety amp Social-Laboral advantages 39
Table 3 1 - Participantrsquos profiles 50
Table 4 1 - Requirement tree with all indicators which considered for decision making process 67
Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed
to be done on them 68
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other
studied 68
Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow) 68
Table 4 5 - Qualitative indicators 69
Table 4 6 - First hand data over literature 69
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow) 70
Table 4 8 - First hand data over literature 70
Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue) 70
Table 4 10 - First hand data over literature 70
Table 4 11 - Final indicators for PCM 72
Table 4 12 - TRC first-hand data over literatures 72
Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow) 72
Table 4 14 - Final Quantitative indicators used for decision making process 72
Table 4 15 - Requirement weights 73
Table 4 16 - Weights of criteria 73
Table 4 17 - Value function for indicators in MIVES 76
Table 4 18 - Indicators normalized values 76
Table 4 19 ndash Indicator normalized values 76
Table 4 20 - Criteria normalized values 77
Table 4 21 - Criteria normalized values 77
Table 4 22 - Requirement normalized values for four indicators 81
Table 4 23 - SI (Sustainability Indexes related to four alternatives) 83
Table A1 1 ndash Cost of project PSM (Hammad 2019) 95
Table A1 2 -Time of project PSM (Hammad 2019) 95
Table A1 3 - Energy utilized during construction (Hammad 2019) 95
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 96
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 99
Table A1 6 6 - Projects cost (Hammad 2019) 99
Table A1 7 - Projects schedule (Hammad 2019 99
Table A1 8 - Energy utilised during construction process (Hammad 2019) 100
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011) 101
Table A2 1 - Professional experience of the company 102
Table A2 2 - Personal experience of participant 102
Table A2 3 - Type of modules 102
Table A2 4 - Type f projects 102
Table A2 5 - Characteristics of production range 103
Table A2 6 - Motivation for doing modular construction 103
Table A2 7 - Panel production conditions 103
Table A2 8 - Level of automation 103
Table A2 9 - Laboral status 104
Table A2 10 - Recycle and Re-use 104
Table A2 11 - Innovative technology integration 104
Table A2 12 - Automation status on waste generation 104
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table A2 13 - Reduction of waste 105
Table A2 14 - Energy consumption status 105
Table A2 15 - Delivery of projects in COVID-19 pandemic period 105
Table A2 16 - Aid organization project delivery 106
Table A2 17 - Post-sale services to client 106
Table A2 18 - Initial costs 106
Table A2 19 - Effective factors on initial costs 106
Table A2 20 - Re-use effect on budget 106
Table A2 21 - positive factors about modular construction to be chosen 107
Table A2 22 - Use of BIM in projects 107
Table A2 23 - Influence of production line on design 107
Table A2 24 - Lack of knowledge among experts 108
Table A2 25 - Transportation regulation effect on projects 108
Table A2 26 ndash Transportable material choice and its effects 108
Table A2 27 - Challenges of using automation 108
Table A2 28 - Contract condition in modular industry 109
Table A2 29 - Participation status in modular projects 109
Table A2 30 - Role of outside general constructor 109
Table A2 31 - Changes in production line and its effects 110
Table A2 32 - Site preparation status 110
Table A2 33 - Challenges with sub-contractors for site preparation phase 110
Table A2 34 - Wrong perceptions for modular products 110
Table A2 35 - Solutions for wrong perceptions 111
Table A2 36 - Recommendations 111
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
1 | P a g e
1 Introduction
Motivations
Construction industry is suffering for a poor productivity problem during the past 60 years in
comparison with other industries and industrialization in construction was suggested by the
investigators to improving the construction performance by applying production technologies and
design standardized products to be built in off-site plants By searching over the off-site methods
modular construction was found which is benefiting its high sustainability and productivity in
comparison with traditional construction approaches
One of the motivations of these study is to study the advantages of modular construction in
order to demonstrate the superior nature of modular construction over traditional methods to be
presented as a reasonable solution for productivity problem the However there are various of
opinions and argues about the beneficiary of this method so that it was decided to analyse them more
deeply in construction management perspective and even get into contact with the industry for
professional confirmation
Another motivation of this study was to contribute to development of modular construction
and find what is holding it back from developing by discovering the challenges in the modular
construction industry and find possible solutions to help for growth
Orientation of previous studies
During past two decades fewer studies in comparison with other innovative methods have
focused on this subject to analyse this method in economic environmental and functional areas to
discover the benefits and make comparisons with traditional construction methods where possible
McKinsey amp company report on 2019 had general overview on its potential advantages challenges
and its ability to raise the productivity in construction processes while introducing the benefits by
making comparisons in projectrsquos schedule budget and environmental performance among modular
and traditional methods and finally shedding a light on dark side which are the obstacles of growth in
industry and then suggesting possible solutions for improvements In addition there are numbers of
articles focusing on the environmental performance of modular buildings by doing Lifecycle
assessment (LCA) analysis on emissions waste generations and consumption primary resources etc
(Mohammad Kamali and Kasun Hewage et al 2016)
On the other side there are studies that made comparisons between traditional and modular
methods of construction to build a specific project based on BIM models and professional data bases
which led to great results that showed numbers of advantages (AWA Hammad et al 2019) (L Aye
et al 2011) (Ali Tighnavard Balasbaneh at Springer-Verlag 2020)
Gap of knowledge
Taking into account of existent researches there is a gap of knowledge which leads to few
questions that still have remained without answer
bull Confirmation of these benefits that came from scientific researches by professional
players in the industry
bull Do these advantages effect the final decision to choose modular method over
conventional way
bull What are the needs of the market that could be as motivations to use modular
construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
2 | P a g e
bull What are the challenges in the industry in the professional point of view
bull Do the solutions that suggested by researchers can be applied in real projects What
are their professional solutions
Objectives of the study
The importance of this study is to resolve the mentioned questions by accomplishing the
studyrsquos objectives that are separated to be achieved by two methods which are qualitative and
quantitative
Survey among the professionals in the modular industry by Online Form
bull To confirmcorrect the data from literature reviews about benefits of modular
construction
bull Their motivations and reasons to choose modular method
bull What are the constraints and obstacles that they are facing
bull Recommendations and solutions for these problems
Decision-making among three modular methods and conventional option by MIVES
bull To discover the advantages in real study cases by comparisons between four
alternatives
bull To examinate the functionality of every alternative in several criterions
bull How much effective these benefits can be in the final decision based on the
requirements of market and their priorities
Limitations
Several obstacles were seen during the study that effected the methodology and input data
significantly Here are some examples
Lack of existence of references related to the subject
Because of the subjectrsquos novelty or less focus the quantity of references is not enough to
cover all the dimensions of study therefore few estimation hypothesis (that were proved by the
results at the end) and consultants with experts were used instead to provide the necessary
information In addition many of the scientific reports and articles were published few months or
even days before the studyrsquos conclusions so that it was decided to be used immediately to improve
the studyrsquos liability
Non-accessible information from companies and scientific articles
There are innovative companies that because of their privacy policies and protection of
innovation could not provide the necessary data about their projects by request even for academic
uses
On the other side scientific papers in some cases were protected and did not have open
access not even with educational access permissions as requests have been denied by the authors
Obstacles caused by global lockdown during covid-19 pandemic
One of the unpredicted challenges that happened during the study was the virus pandemic
that affected the world negatively and this study was not an exception From on-site project and off-
site factory visits interviews with experts in the industry etc were cancelled Numbers of regions went
to full shutdown including offices factories etc which resulted in reduction of participations in online
survey form as well Therefore it was decided to select five most suitable participants to be analysed
instead of planed massive quantity of results
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
3 | P a g e
Organization of the thesis
⎯ Chapter two state of the art explaining the productivity problem history types and
phases of modular construction and literature reviews on benefits and challenges
⎯ Chapter three The online survey among modular players in the industry
⎯ Chapter four MIVES multi-criteria decision-making approach
⎯ Chapter five Conclusions and findings
⎯ Chapter six Recommendations
⎯ Chapter seven references
⎯ Anexo A (Input data references)
⎯ Anexo B (Survey QampA) 2
Kewwords Sustainability Modular construction MIVES Productivity rate Prefabrication Lifecycle assessment (LCA)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
4 | P a g e
2 State of the art Productivity problem in construction industry
Status of productivity rate of construction industry among other industries
It has been decades that construction industry is far behind the other industries in terms of
productivity rates Attempts had been done by innovative players in the industry but still the
difference is too enormous which the demands for improvement are needed
Globally construction sector labour-productivity growth averaged 1 percent a year over the
past two decades compared with 28 percent for the total world economy and 36 percent for
manufacturing If construction productivity were to catch up with the total economy the industryrsquos
value added could rise by $16 trillion a year (McKinsey 2019)
It can be said that the building industry is one of the key industries in the general economy
The construction sector typically comprises 8-10 of the Gross Domestic Profit (GDP) of a Western
economy (McGeorge amp Palmer 2002) Therefore only 10 improvement in construction
performance can represent a 25 increase in GDP (McGeorge amp Palmer 2002) Therefore there is
no doubt that improving productivity in the building industry will contribute positively to the general
economy
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
5 | P a g e
The UK has a problem with productivity and the construction sector has poorer productivity
growth rates than any other Simply put productivity is the amount of stuff (whether goods or
services) that is produced by a person in an amount of time UK productivity is lower than it was in
2008 and the construction industry has not seen any significant growth in productivity in the last 20
years (Figure 22)
Figure 2 2 - UK productivity status (Office for National Statistics -ONS)
Not all the regions are struggling at the same rate and the reasons which will be discused
furthermore can be the insterest of regulators to support innovations and new solutions which can
improve the productivity in construction industry(Figure 23)
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS)
The result is that between 70 and 90 of projects exceed the original planned cost and that
the overrun commonly varies between 50 and 100 of budget Construction also suffers from 57
of effort on non-value-added activities compared with 26 within manufacturing (Figure 24)
These productivity rates had experienced severalrises and downs in some periods which is
because of increase of demandas of housing that results a boost in construction industry in order to
provide the needs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
6 | P a g e
Figure 2 4 - Value added comparison among industries (ennovacom)
Reasons of poor productivity
There are numbers of reasons for this poor performance The industry is extensively
regulated very dependent on public-sector demand and highly cyclical Informality and sometimes
corruption distort the market Moreover poor project management and execution insufficient skills
inadequate design processes and underinvestment in skills development RampD and innovation can
affect the productivity indirectly by decreasing the feasibility and value of the activities and add extra
costs on the project
Another key factor that causes a disruption among construction players which reduces the
average productivity rate is the lack of harmony in productivity between the players In other words
The sector divides mainly in two large-scale players involved in heavy construction such as civil and
industrial work and large-scale housing and a large number of firms engaged in fragmented
specialized trades such as mechanical electrical and plumbing work that act as subcontractors or
work on smaller projects like refurbishing single-family housing The first group manages to have 20
to 40 percent higher productivity than the second However even in the more productive heavy
construction sector there are endemic-potentially structural-challenges in meeting cost and schedule
commitments on megaprojects and players routinely subcontract specialized trades (McKinsey amp
Company 2019) (Figure 26)
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
7 | P a g e
Figure 2 6 - Fragmentations between construction industry players and their various productivity rates (McKinsey 2019)
Solutions for improvement
Nowadays there are solutions which are being used in construction world such reshaping the
regulation rewiring the contractual framework to reshape industry dynamics rethink design and
engineering processes improve procurement and supply-chain management improve on-site
execution infuse digital technology new materials and advanced automation and reskill the
workforce Each region based on their capabilities potential and Infrastructures would take a decision
which ways can be applied to increase the productivity in construction projects in a short or long
period
bull Redefine regulation Actions include streamlining permitting and approvals processes as
Australia has done reducing informality and corruption and encouraging transparency on cost
and performance as the International Construction Measurement Standards project does Many
governments allocate grants for innovation and training Germanyrsquos Federal Ministry of Transport
and Digital Infrastructure (formerly the Federal Ministry of Transport Building and Urban
Development) for instance supports RampD through studies in building materials Best practice
regulation would include moving toward outcome-based more standardized building codes and
consolidating land to promote scale Examples include Singaporersquos move to allow cross-laminated
timber (CLT) for high-rise structures and Japanrsquos promotion of scale through land pooling
bull Re-arrange the contractual framework Establishing a ldquosingle source of truthrdquo on projects for
monitoring progress early potentially supported by collaborative technology helps to minimize
misalignments and enable joint corrective action The data already exist to fundamentally
improve the accuracy of cost and schedule estimates Where players continue to use traditional
contracts they should introduce incentives that significantly improve performance and alignment
not at a trade or package level but at the project-outcome level To move toward best practices
appropriate alternative contracting models such as integrated project delivery (IPD) help build
long-term collaborative relationships Relational contracts will need to become more prevalent
than transactional contracts Sufficient investments in up-front planning incorporating all partiesrsquo
input have been shown to raise productivity substantially Smart Contracts are another example
of these solutions which during recent years is being identified by the major players A smart
contract is a computer program or a transaction protocol respectively which is intended to
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
8 | P a g e
automatically execute control or document respectively legally relevant events and actions
according to the terms of a contract of an agreement or of a negotiation The objectives of smart
contracts are the reduction of need in trusted intermediators arbitrations and enforcement costs
fraud losses as well as the reduction of malicious and accidental exceptions (Tapscott Don
Tapscott Alex amp Savelyev Alexander 2016)
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom)
bull Off-site production shift The biggest impact on productivity would come from moving toward
thinking about construction as a production system where possible encouraging off-site
manufacture minimizing on-site construction through the extensive use of pre-cast
technology assembling panels in factories and then finishing units onsite
bull Improve on-site execution There are four key approaches that are well known in the industry
but have not been universally adopted First is the introduction of a rigorous planning process
the Last Plannerreg System (LPS) is a useful tool to ensure that key activities are achieved on
time and on budget The use of integrated planning tools on a large-scale oil and gas project
for instance achieved a 70 percent increase in the projectrsquos productivity Second is reshaping
the relationship and interactions between owners and contractors and key performance
indicators (KPIs) being agreed on and used at regular performance meetings at which on-site
issues are resolved Complementing commonly used KPIs with additional forward-looking plan
conformance metrics to identify and subsequently reduce variance is critical Third is
improving the mobilization for new projects by ensuring that all pre-work (for instance
obtaining approvals and developing project milestones) has been completed prior to starting
onsite Finally there is a need for careful planning and coordination of different disciplines
on-site along with the application of lean principles to reduce waste and variability On-site
productivity can be increased by as much as 50 percent by implementing a cloud-based
control tower that rapidly assembles accurate data in near real time that is both backward-
looking and predictive (for example using plan conformance and other variability and
inventory metrics)
bull Introduce digital technology advanced automation Companies can start by making 3D
building information modelling (BIM) universal within the company alongside use of digital
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
9 | P a g e
collaboration tools drones and unmanned aerial vehicles for scanning monitoring and
mapping They can put themselves at the cutting edge by using platforms such as 5D BIM to
establish transparency in design costing and progress visualization (Figure 28)
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom)
Advanced analytics enabled by the Internet of Things to improve on-site monitoring of
materials labour and equipment productivity and digital collaboration and mobility tools (such as
construction management apps loaded on mobile devices) to better track progress and collaborate in
real time (Figure 29)
Figure 2 9 - Digital construction organization (wwwbimcommunitycom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
10 | P a g e
Advanced automated equipment and tools such as bricklaying and tiling robots can accelerate
on-site execution The field of digital fabrication (dfab) is quite broad and has many applications Dfab
techniques are based on the combination of computational design methods and automated
construction processes which are typically categorized as subtractive formative or additive
(Kolarevic 2003) The use of subtractive and formative digital fabrication is becoming mainstream in
the prefabrication (off-site) of building parts (eg by using laser cutting CNC milling etc)
In recent years additive fabrication processes especially 3D printing have experienced a
rapid development in many industries As interest in additive fabrication grows research into large-
scale processes begins to reveal potential applications in construction (Labonnote et al 2016)
Existing additive dfab technologies can be classified in two big clusters on-site and off-site
construction technologies On the one hand on-site digital fabrication aims to bring additive
fabrication processes on construction sites
Sousa et al (2016) classified on-site technologies in three main categories large scale robotic
structures mobile robotic arms and flying robotic vehicles A well-known example from first category
is Contour Crafting a robotic structure for 3D printing large-scale construction developed at the
University of Southern California (Khoshnevis 2004)
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom)
bull Reskill the workforce Change in the construction sector cannot be achieved without
investment in retooling a workforce that is aging and changing its makeup through migration
Construction firms and workers need to continuously reskill and train to use the latest
equipment and digital tools In the mix should be apprenticeship programs such as the one
run by Siemens in the United Kingdom training frontline workers in core skills that are
currently underdeveloped and increasing stability in the workforce by breaking seasonality
and cyclicality
Brief on modular construction
History of modular construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
11 | P a g e
bull 1800s
In 1830 he first documented prefabricated home was created by London carpenter John
Manning for his son who was moving from England to Australia Manning built a prefabricated house
in pieces then shipped it to the Land Down Under for easy assembly In 1840 Modular construction
made its way to the United States in response to the housing needs of the California Gold Rush The
Crystal Palace was built for Britains Great Exhibition and remains one of the most famous examples
of early modular construction in 1851 Designed in less than two weeks it utilized light and
inexpensive materials such as iron wood and glass it was constructed in only a few months
Afterward the palace was dismantled moved and rebuilt at another location
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom)
bull 1900s
Augustine Taylor a builder in Chicago devised the balloon-frame method (Figure 212)
enabling walls to be built offsite then transported to the intended construction site for speedy
assembly The rise of catalogue houses happened Between 1908 and 1940 when Sears Roebuck and
Co sold more than 500000 prefab homes through its catalogue straight to consumers At the time
these houses cost less than two-thirds of conventionally built homes and many still exist throughout
the United States
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull WWII Housing Boom
Prefab structures continued into World War Two to meet the growing demand for mass
accommodations for military personnel So-called Quonset Huts or Nissen Huts in the UK
comprised of corrugated steel were introduced for domestic military and institutional uses
When soldiers began returning home in the United States there was a need for rapid
construction for new homes to accommodate these expanding families Once again modular
construction serviced those needs because of its efficiency reduced costs and quick construction
Today many of those units are still in use
bull Prefab in Post-war Europe
The situation in Europe was more difficult although millions of people had no place to live on
the Old Continent due to the destruction of the Second World War people were unwilling to accept
prefabricated construction In Germany which had not only lost 25 percent of its entire housing stock
to bombing but also had to integrate 12 million refugees from former German territories in Eastern
Europe one form of prefabricated housing was used extensively the Nissen Hut (similar to the
Quonset hut) An attempt was also made in post-war France to combat housing shortages with the
help of prefabricated houses In 1944 Jean Prouveacute was already commissioned by the Ministry of
Reconstruction and Urban Planning to build 800 houses as emergency shelters that could be easily
disassembled However only 400 of these Maisons agraveportique which were equipped with an axial
steel frame were ever erected Prouveacutes Alba houses developed for the Abbey Pierres homeless
organization in 1956 were also not a success (Peter Goumlssel Arnt Cobbers Oliver Jahn 2012
architectureweekcom)
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8 meters (modulartch)
bull The Pre-fabulous 60s
The 1960s were a period of social transition in which attitudes towards prefabricated housing
also changed During this era which was marked by space travel the moon landing and even childrens
books that predicted weekend trips to distant galaxies prefabricated construction was discovered both
as a form of artistic expression and as a technical means of creating houses to provide a basis for new
lifestyles which seemed to be imminent in a society characterized by an extremely optimistic view of
progress
These approaches supported the idea of creating megastructures out of residential capsules
the architect Moshe Safdie who was only 24 at the time presented his megastructure Habitat 67 at
the Expo 67 in Montreal 158 housing units consisting of 354 concrete modules assembled as a
conglomerate
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The British architectural group Archigram developed building structures made of residential
capsules as an architectural Utopia which could be expanded at will and joined to form entire cities
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau)
bull Eco-conscious 70s
In 1972 the Japanese architect Kisho Kurokawa built the Nakagin Capsule Tower in Tokyo
housing cells were layered around a prefabricated concrete core to form a fourteen-story residential
tower(Figure 215) The idea of residential capsule megastructures was repeatedly revived as in Zvi
Heckers Ramot housing development in Jerusalem in 1974
The ecology movement of the 1970s brought an end to this euphoria regarding technological
progress and futuristic architectural dreams Now highly modern building materials that did not seem
to be in harmony with a return to nature such as plastic or aluminium fell into disrepute A new
perspective of view replaced as a priority to choose the material types which have the minimum
relation with non-renewable resources
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
bull 90s
This was further exacerbated by the fact that prefabricated elements had often been used to
build high-density housing which was now generally viewed negatively Hence prefabricated building
now came to be associated with the aesthetic and social failure of deindividualized megalomaniac
prefabricated slab housing blocks clustered on the periphery of large cities Thus the acceptance of
the prefabricated house in large parts of Europe remained low up until the 1990s
Prefabricated construction only gradually began to again emancipate itself from a homespun
cheap mass-produced image during the 1990s This is mainly due to the use of computer-operated
programs in the design and production processes The prefabricated housing industry now stands at
a juncture reminiscent of the dynamism of the 1920s and 1930s
bull Modern days
For many years now companies like Muji in Japan or BoKlok in Scandinavia and more recently
also in Poland and England have been supplying prefabricated houses in large numbers In Sweden
alone with only nine million inhabitants 14000 units are sold every year Muji offers models designed
by Kengo Kuma and Kazuhiko Namba that are as simple as they are elegant and far more interesting
than the building-kit houses offered by the multinational concerns Mitsubishi Toyota and Panasonic
(deluxemodularcom 2019)
Countries around the world have enlisted prefab and modular construction methods for
decades For example an estimate of all detached homes that are prefabricated in each country
shows a potential for growth off 84 in Sweden 5 in the United States 9 in Germany 20 in the
Netherlands and 28 in Japan
Today prefabrication and modularization are utilized in the construction of hotels apartment
buildings offices hospitals and schools in every major US city Here is a rundown of the percentage
per industry of prefabricated structures that use some form of modular construction
(deluxemodularcom 2019)
bull 49 of healthcare facilities
bull 42 of college buildings and dorms
bull And 42 of manufacturing buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Types of modular product
Module architectural types
The products can be categorized by its functions dimensions material or type of its operation
etc Here they will be introduced by their general characteristics
bull Bathroom pods
Bathroom pods are commonly used in the construction of most hotels and apartment
buildings these days and becoming used more for residential housing The main drivers for choosing
a modular pod method are
o The cost savings that can be made by building repeated designs in a factory
environment
o Higher quality finish
o Rapid installation
o No trades on site
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom)
Pod Construction Process can be various but the most common steps can be as below
(httpswwwhowickltdcom)
Once the bathroom specification has been finalized and the design completed the
machine files are issued and the framing can be produced
The frames are rolled out of the machine ready for assembly
The panels are assembled
The panels are then fitted with the internal boarding and finished with tiles or a
waterproof lining
The walls floor and roof are joined to create the room structure and the joints sealed
The fixtures and fittings can then be installed including
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
16 | P a g e
o Bath or shower
o Toilets
o Basins
o Lights
o Mirrors
o Cabinets
The plumbing and electrical components are connected
The pods are then subjected to an electrical test and a pressure test to ensure there
are no leaks (Figure 217)
The pods are then sealed to prevent access ready for transportation
Once on site the pods are slid into position and connected to the power and water services
This process greatly reduces the build time as there are no requirements for trades on the site As the
pods are sealed until the building is completed there are reduced chances of them being damaged
during the building construction phase
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom)
bull Kitchen pods
These pods are less common but are also becoming more frequently used All the appliances
and electrics can be fitted in the factory removing the need for work on site Kitchen pods are ideal
for renovating older or industrial buildings as all the electrical services for the building can be
integrated into the pod From student accommodation to residential flats modular kitchen pods are
suitable for a variety of different sectors and uses and because they are designed bespoke to each
clientrsquos exact specifications they can be anything from a fully fitted kitchen to a small kitchenette
Each modular unit is completely customisable from the worktops to the splashbacks and integrated
white goods
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom)
bull Volumetric and modular rooms
Volumetric and modular rooms are becoming widely used for buildings that have a repetitive
nature Common structures include
bull Hotels
bull Apartments
bull Student accommodation
bull Schools
bull Hospitals
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The benefits of being able to manufacture the complete unit in the factory (including the
bathrooms and fitting of furniture) are
o No weather delays
o Superior finish quality
o All the electrical and plumbing works are done in a controlled atmosphere
o The rooms are sealed before moving to site restricting unauthorized access
Modular rooms production process can be explained as below
Once the building design has been completed and the individual modules specified the
framing components can be made on a just in time basis for site delivery
A typical assembly process would consist of
The floor cassette is rolled and the flooring boards are attached along with the
required insulation and services
The wall and ceiling frames are assembled
The internal lining is fitted and painted
The wall frames are then attached to the floor cassette (Figure 220)
Figure 2 20 - Production steps of floor cassette to walls and their attachment together (wwwhowickltdcom)
The ceiling frames are then fitted
The bathroom can then be fitted and plumbed as well as the electrical fittings and
wiring
The wall and ceiling insulation is added to the frame
The fit-out can then be completed to the desired specification
A hotel module for example would feature carpets bed bedside furniture desk
wardrobe TV system air-conditioning (either vents from main system or stand-alone
unit) bathroom fittings and fixtures
Once completed the electrics are checked and the plumbing is pressure tested
A protective cover is then added for transport and the unit is delivered to site
On-site the units are craned into position and joined
The services are connected
The building is then roofed and clad to the required specification In some cases the cladding
can be fitted during the module assembly further reducing the on-site work
bull Modular Trailers
Outside of modular homes modular trailers are probably the type of modular building that
people are most familiar with These buildings have a lot of applications and are often used as a
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
19 | P a g e
temporary space solution These trailers can be relocated for several times and are well-equipped as
well Temporary pre-semester school classes and temporary offices can be two examples of these
trailers uses
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom)
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom)
bull Containers
When looking at modular containers they are structures that are typically used to contain a
shiprsquos cargo When Shipping containers were originally created they were designed with modularity
in mind They were required to withstand all kinds of abuse as they journey through some of the
worldrsquos harshest climates From salt water to freezing temperatures a shipping container is meant to
handle the worst of the worst while protecting some of the worldrsquos most precious cargo Comprised
of Corten steel it is in a shipping containers DNA to protect itself from any corrosion or rust and when
they fall off the ship they can take up to a week to sink With more boxes being imported than
exported we have an opportunity to reuse something that is desperately looking for a new home
There has been a shift recently where after these buildings serve their purpose as shipping containers
they are reused fitted with windows doors HVAC units etc And made into an office environment
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The biggest benefit of these containers is they are cheap very portable and easy to install on site
However since most of the time these buildings are retrofitted and remodelled into modular
buildings they usually do not have a lot of flexibility in layout or their dimensions
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom)
Shipping containers act as the exoskeleton of each module The original structure will frame
the HVAC wiring lighting plumbing appliances and wall finish materials Because containers were
built to be durable and mobile they can be transported by train tractor-trailer boat or in some cases
a powerful pickup truck Forklift pockets and corner castings allow the containers to be moved smaller
distances by crane and forklift Shipping containers empower you to move your modular structures
without sacrificing the structural integrity or damaging the modulersquos contents
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull Office Complexes
Office complexes will take several office modules and combine them to assemble a much
larger fully functioning office building Just like all modular construction these modules are
fabricated in a manufacturing environment except when these projects reach the job site they
function more similarly to a full-fledged construction site Generally the module will need a crane to
lift the section from the ground and place it in the correct spot to assemble the building Next the
workers will go through that module and do all things necessary to attach and hook up the piece
Then the next piece is put in place and these steps are repeated and again until the building is
finished
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom)
bull Modular enclosures
For instance one of the major electric utilities in the Northeast using Modular Construction is
Wunderlich Malec Integrated Control Enclosures since 2001 A standard 16times50times11-foot enclosure
with twenty (20) protective relay and control cabinets marshalling cabinets HVAC fire and security
completely installed wired and tested at the factory prior to shipment
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-Malec (wmengcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
22 | P a g e
Module structure types
Modular structure types can be categorized by their materials or structural formation
o Steel Modules
bull 4-sided modules
In this form of construction modules are manufactured with four closed sides to create
cellular type spaces designed to transfer the combined vertical load of the modules above and in-
plane loads (due to wind action) through their longitudinal walls The cellular space provided is limited
by the transportation and installation requirements Depending on location and exposure to wind
action the height of buildings in fully modular construction is in the range of 6 to 10 storeys Modules
are manufactured from a series of 2D panels beginning with the floor cassette to which the four wall
panels and ceiling panel are attached generally by screws The walls transfer vertical loads and
therefore the longitudinal walls of the upper module are designed to sit on the walls of the module
below
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo)
It consists of a modular structure of high strength galvanized steel which is also used as the
basis for building closure Steel physical properties make it one of the most versatile materials for
construction since it is
ELASTIC Steel does not break as it has a great strength and elasticity It is easily workable and it has
a great advantage over traditional construction
RECYCLABLE Steel is 100 recyclable
DURABLE With zinc application it can become galvanized steel which has extraordinary durability
properties
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo)
bull Partially open-sided modules
4 sided modules can be designed with partially open sides by the introduction of corner and
intermediate posts and by using a stiff continuous edge beam in the floor cassette The maximum
width of opening is limited by the bending resistance and stiffness of the edge member in the floor
cassette Additional intermediate posts are usually square hollow sections (SHS) so that they can fit
within the wall width
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
24 | P a g e
bull Open sided (corner-supported) modules
Modules may be designed to provide fully open sides by transfer of loads through the
longitudinal edge beams to the corner posts The framework of the module is often in the form of hot
rolled steel members such as Square Hollow Section (SHS) columns and Parallel Flange Channel (PFC)
edge beams that are bolted together
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported module
(wwwsteelconstructioninfo)
bull Modules supported by a primary structure
Modular units may be designed to be supported by a primary structure at a podium or
platform level In this case the supporting columns are positioned at a multiple of the width of the
modules (normally 2 or 3 modules) The beams are designed to support the combined loads from the
modules above (normally a maximum of 46 storeys) The supporting structure is designed
conventionally as a steel framework with beams and columns that align with multiples of the module
width and provides open plan space at ground floor and below ground levels This form of construction
is very suitable for mixed retail commercial and residential developments especially for residential
units above commercial areas or car parking etc particularly in urban projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the lower levels
(wwwsteelconstructioninfo)
o Wood structure
Back in the days of the very first modular buildings wood was the modular construction
material of choice and nowadays it overwhelmingly remains the most used for these projects due
to its abundance and cheaper initial costs Wood-framed modular buildings however have several
notable limitations that might give a property developer pause and may even prove more costly in the
long-term repairs
Wood often lacks the strength necessary to support large building projects especially those
of multiple stories Due to this weakness wood-framed buildings are typically no taller than a few
stories a considerable limitation for someone looking to build a hotel or apartment building as
examples
Wood is flammable and vulnerable to fire which could severely damage the structural
integrity of the building requiring replacement or even worse leading to a total collapse
Wood tends to warp over time resulting in a lower quality building in the years after
completion Combined with its susceptibility to pests and mold selecting wood for a modular
structure may prove to be the more expensive choice in the long term considering repair costsmdasheven
despite initial savings
Wood is among the most wasted materials used in modern construction On average 20 of
construction lumber typically ends up in landfills leaving a larger environmental footprint than other
alternatives (httpswwwdeluxemodularcom)
Considering all those negative points mentioned earlier there are numbers of regions that
still are oriented to wooden structures as this type of housing is part of culture of the society because
of traditional architecture etc therefore typical clients prefer to build the type of accommodation
that they trusted for many years as it became the main demand of market Accessible local resources
availability of necessary knowledge for construction and compatibility of labour forces with this
method are other reasons to be chosen over the other alternatives
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
26 | P a g e
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other metals
(vanguardmodularcom)
o Concrete modules
Precast concrete is a well-established and efficient manufacturing industry and products
range from hollow-core slabs to beams and columns in structural frames Concrete modules can be
manufactured in two ways either from precast 2D wall floor and ceiling panels or as 3D modular
units which are generally cast with an open base Concrete modules are often used in high-security
applications as they are extremely resistant to damage
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma Beton)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Types of modular buildings based on operation period
bull Relocatable Buildings (RB)
Relocatable modular buildings are designed to be reused or repurposed multiple times and
transported to different sites Relocatable Building as defined in the 2015 International Existing
Building Code a partially or completely assembled building constructed and designed to be reused
multiple times and transported to different building sites
bull Permanent Modular Construction (PMC)
PMC is an innovative sustainable construction delivery method utilizing offsite lean
manufacturing techniques to prefabricate single or multi-story whole building solutions in deliverable
module sections PMC buildings are manufactured in a safe controlled setting and can be constructed
of wood steel or concrete PMC modules can be integrated into site-built projects or stand alone as
a turnkey solution and can be delivered with MEP fixtures and interior finishes in less time with less
waste and higher quality control compared to projects utilizing only traditional site construction
Common uses of modular buildings in the market
o Education
Relocatable buildings have become a critical factor in managing student demographics and
increasing enrolments Relocatable classrooms are also ideal for swing space during new construction
or renovation Convenient flexible cost-effective temporary buildings can be delivered and
operational in as little as 24-hours These classrooms are measured for quality and code compliance
by state or third-party agencies through routine and random inspections testing and certification
services Customers may choose single classrooms or arrange multiple buildings in clusters to create
a campus feel MBI members supply steps decks ramps and even furniture Members also offer
lease purchase and lease-to-purchase financing for a variety of public and private school needs
These classrooms are sometimes referred to as temporary portable or mobile classrooms
o Construction-Site
Relocatable buildings have their roots in construction site trailers where speed temporary
space and relocate-ability are important Used as standard field offices construction site and in-plant
buildings are available for immediate delivery Standard construction is wood but steel units are
available to meet non-combustible requirements In-plant buildings are available as single- or two-
story units for industrial environments with noise reducing insulation and are typically moveable by
forklift and include electrical and communications wiring heating air conditioning and even
plumbing
o Healthcare
Relocatable buildings for healthcare applications are designed and constructed to
uncompromising standards of quality A customerrsquos new clinic hospital extension laboratory
diagnostic centre MRI unit dentist office or other medical facility can be open for business and
serving communities in as little as a few days Is your interest in serving patients as quickly as possible
in the safest and aesthetically pleasing environments available These facilities offer quick quiet safe
and clean buildings with an unlimited choice of interior deacutecor and furniture and equipment leasing
o General Administrative and Sales Office
When production demands increase relocatable buildings can temporarily enlarge a current
facility without permanent alterations to the site Because the space is not permanent many
companies are able to expand without the budget approval process necessary for traditional capital
expenses Relocatable offices can be single- and multi-story buildings configured to include
independent offices conference rooms and large open spaces for cubicles or other partition systems
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
28 | P a g e
Large and small businesses as well as local and state governments are typical users of relocatable
office space
o CommercialRetail
Earlier occupancy means quicker return on investment For retail occupancies this can mean
significant cash flow advantages Standard floorplans are available for immediate delivery while
custom buildings are built to specifications in weeks not months Unique to the modular process is
concurrent construction site-work occurs while buildings are being put together in a quality-
controlled factory Typical retail applications include new home sales centers banks golf pro shops
automobile fleet ownerships college bookstores and concession stands If a clientrsquos emerging
business needs are short-term temporary space will accommodate their financial situation space
requirements and deadlines
o Security
Relocatable buildings can be custom built for a variety of access and control situations Toll
booths tickets sales offices guard stands and weigh stations are common applications One and two-
story wood and steel buildings have straight walls or walls that are tilted to improve views and reduce
glare
o EmergencyDisaster Relief
There is simply no other means of providing fast transitional shelter and basic community
needs following natural disasters than relocatable buildings Relocatable buildings can be quickly and
efficiently deployed for emergency shelter medical and educational needs or to accommodate relief
workers
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction report MBI 2019)
Construction phases
Modular construction is the process of manufacturing multiple building sections in a facility
for assembly at a remote building site The building sections called modules will fit together once
assembled on site with plumbing HVAC and electrical connections running throughout One of the
great advantages in the modular construction process is that many of the processes happen at the
same time which can cut the construction time in half There are six common steps to complete a
modular project Design amp Engineering Permits amp Approvals Site Development Plant Fabrication
Transportation and Installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
29 | P a g e
Figure 2 34 - Overlaps of phases in modular construction project
o Step 1 Design
The design phase of the modular building process creates a description of the building usually
represented by detailed plans and specifications A thorough customer consultation with a Palomar
project manager gathers the information required to develop the building plan Once this information
has been gathered the design team will produce the ideal modular building design to fit the customerrsquos
needs
o Step 2 Engineering
Each building design goes through the engineering department for an engineering review Like
site-built structures modular buildings are subject to a series of national state and local building
codes that ensure the building meets a set of standards for safety and performance State level
building codes can be superseded or augmented by local building code requirements and then must
confirm the design proposal meets all applicable building codes
o Step 3 Permits amp Approvals
A construction permit or building permit is a permit required in most jurisdictions for new
construction or major renovations Typical construction permits required can include
Site plan
Building permit
Mechanical permit
Plumbing permit
Concrete permit
Encroachment permit
Sign permit
Flood district development permit
The building owner is ultimately responsible for securing building permits for work on their
property In practice most building owners appoint the general contractor as an authorized
representative so the contractor can obtain the required permits The building owner is advised to
confirm that the general contractor has secured the proper building permits for their project Failure
to obtain the proper permits can result in significant fines penalties and even demolition of
unauthorized construction
o Step 4 Site Development
One of the advantages inherent in modular construction is that the site development and
building foundation are prepared while the modules are being fabricated at the manufacturing facility
and transported to the job site The site development and building construction processes happen
Permits
Design amp Engineering
Site Development
Plant Fabrication
TransportationOn-site installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
30 | P a g e
concurrently instead of sequentially like site-built construction Projects are developed on a variety of
geographic settings typical site development includes
Surveying
Demolition
Excavation
Grading
Site drainage
Foundation construction
Utility installation
There are two primary modular building foundation classifications on-grade and raised or full
foundation An on-grade foundation is generally for permanent installations and is more expensive A
full foundation can be used for temporary or permanent structures it is less expensive to install and
it is more cost effective to relocate the building later while causing minimal site disturbance
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom)
bull Step 5 Plant Fabrication
There are two scenarios for steel modular constructors There are few numbers of off-site
plant which built their own steel frames inside the plant because of high initial budget and it is
common that it would be cheaper to order the frames from another supplier and transfer to the
factory to assembly with other parts The steel frame is then loaded on the main factory production
line where the sub-floor is insulated and floor decking is assembled atop the steel frame As the
module moves down the production line framed wall sections are fabricated insulated and hoisted
in place The truss roof assembly is built in components at ground level before it is hoisted into place
The module proceeds down the line where mechanical electrical and plumbing services are installed
while the last of the insulation goes into place Interior finishes like drywall painting and flooring are
applied while doors and windows are installed
On the last stop of the production line the exterior finish and trim are applied before the
module is prepared for transportation
During construction at the manufacturing facility a third-party inspection agency is present to
ensure the modules are built in compliance with building code
bull Step 6 Transportation
The fabricated modules are shipped over the road by carriers that specialize in modular
building transportation In most US jurisdictions building shipping limitations are 16rsquo in width and
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
31 | P a g e
between 70rsquo amp 90rsquo in length per module Permissible Maximum Dimensions of Lorries in Europe and
UK for Lorry or Trailer are 4m in height 255m in width and 12m in length (International
Transportation forum)
bull Step 7 Installation
A general contractor often one specializing in modular construction will install the modules
complete any on site finish out and make the final utility connections
The choice of building foundation determines how the building will be installed Permanent
semi-permanent and on grade foundations will require the modules to be set with a crane Raised
foundations typically used for temporary buildings allow the modules to be set in place through
simple mechanical methods
With the modules in place final finish out of the interior and exterior proceeds Finish out can
include electrical and mechanical system connection between modules stairs wheelchair ramps
skirting exterior siding trim and utility connections
Literature review on possible advantages
Modular construction comes with advantages which motivates investors and innovative
constructors to apply this method on their future projects Here these benefits are being classified in
various sections such as schedule economic environmental health and safety and social-laboral
advantages
Scheduling benefits
While on-site constructors are complaining about the slow progression of construction
activities and delays on project deliveries the struggle is still to be continued to find new methods to
improve productivity and progression speed while maintaining the quality at a reasonable level
whether if its achievable or not On the other side modular construction because of numbers of
reasons is making a significant boost in term of time management in many phases As it can be seen
in figure 236 McKinsey amp Company report explains that approximately between 20 - 50
scheduling improvement can be achieved in comparison with traditional on-site construction
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method (McKinsey amp Company
2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
32 | P a g e
To be more specific literature reviews identified numbers of benefits in most of the
constructive activities from design to on-site installation As the table 22 illustrates off-site
manufacturing brings most of the time saving to the project by better coordination precise quality
management and not being affected by the on-site bad conditions Table 2 2 - Possible benefits in projects scheduling
In addition design can the ability to be applied in multiple projects instead of just one which
accelerates the project schedule significantly Various overlaps in modular construction can save lots
of time in projects such as site preparations off-site manufacturing and on-site installation with each
other
The acceleration in design process which would be ideal for schedule-critical projects (for
instance emergency accommodation for people who are affected by natural causes) also Long-lead
items can be stocked Fabrication can start and finish earlier in this case In the real state point of view
in the design phase there is one huge benefit which will be so handy when nearly ldquoshovel-readyrdquo
design documentation is needed for clients and site selectors (wwwmcminnvillebusinesscom)
The simplicity precision and clarity of the design plans in modular projects can increase the
possibility of using advanced software such as BIM which reduce the period time of designing phase
significantly With the increasing the possibility of integration of BIM in construction project
incorporating modular building technologies into project becomes more developed and
manufacturing and construction process could be streamlined (Na Lu and Thomas Korman 2010)
About 90 percent of the build activity takes place indoors which means the building process
is nearly guaranteed to stay on schedule That predictability and reliability enable you to count on
timely project completion If a skilled modular crew only spends half the time building your structure
than a site-built crew would your labour cost also gets cut in half
Because of stability of production location there are numbers of advanced technologies
which are being used in other industries production lines that can be used in these off-site facilities in
order to improve the productivity and reduce the timeline of the activities
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
33 | P a g e
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom)
The nature and outdoor construction have always mutual effects on each other mostly in a
disfavour way Site conditions often cause negative impacts on the activities which lead delays quality
insurances or stop them because of safety matters In result the project schedule can be changed and
most of the times unpredictive delays will take place in the timelines In addition there are sites which
the possibility of on-site construction for most of the year is almost zero percent or if exists would be
limited because of life risks for workforce A reasonable solution for these cases is off-site construction
which in most of them reduce the nature effects Thus factory-based production can make a
revolutionary impact on the project scheduling In modular method 60-90 of the construction work
is completed in a closed factory environment and this mitigates the impact of unfavourable weather
(FLORI MURESAN on ny-engineerscom)
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
34 | P a g e
Machinery equipment can take place in mentioned phase instead of human labour which can
boost the productivity quality as well as the time reduction Robotic assembly is one the efficient
examples of this technology One of the very first EU projects carried out in the Robotics Lab
(httproboticslabuc3mes) located at the Carlos III University named FutureHome-IF7 project The
done research was focused in the robotization and industrialisation of the final stage of the
construction process by mean of modular construction (Martinez 2008)
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes)
Economic benefits
Economic advantages can always attract investors to develop innovations Since in a project
time and cost have a direct and mutual relation with each other most of the benefits which were
mentioned earlier in the schedule section can also make positive impact in projectrsquos economy In
some cases these benefits equal to the initial costs which will be discussed later in challenges As it
was mentioned earlier the design plans can be repeated multiple times in projects because of
similarity of requirements that can save design costs in future budgets
Modular building because of their standardization and classification in design phase can be
more compatible with advanced such as BIM (building information modelling) BIM technology in its
5D phase does cost estimating material quantifications and pricing to be automatically generated
and modified while changes are applied for each building module (Na Lu and Thomas Korman 2010)
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
35 | P a g e
Foundations do not have complexity in modular buildings because of weight of the modules
which have to be manufactured lightly in order to be transported simpler to the location
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk)
Also because of the high quality and precise off-site execution there are fewer reworks in
modular products which can save costs in projects Off-site manufacturing provides more economic
benefits such as reduction of salary wages due to a smaller number of workers and more specialized
ones and adding values to each hour of work by increasing productivity to the activities
Moreover massive orders of Materials to the supplier can bring more quality to the material
multiple discounts on each offer and add more stability in prices of material in instable markets Table 2 3 - Economic benefits in modular method
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
36 | P a g e
Environmental Benefits
A highlight among the modular constructionrsquos benefits is in the environmental point of view
Since the modular buildings are friendly with environment many clients are willing to change their
method to this ecological approach in order to make their projects more sustainable and promote
their product in the market as an innovative constructor in the industry such as ldquoGrupo Consentinordquo
which not only builds modules that are available to use solar panels as energy supplier but recycle
many structural and non-structural elements and reuse them in another projects Waste management
can be applied simply in modular construction by reduction in waste during off-site production recycle
and reuses in elements in several projects use of automation can secure waste reduction at a high
rate It has been proven that modular construction can reduce waste by up to 90 thanks to off-site
construction (JAHNAVI SAJIP ny-engineerscom)
Agostinho Mendonccedila in 2018 did a research about reuse in construction industry which
shows a great improvement in terms of sustainability During 2022 FIFA World Cup in Qatar football
fans will have the opportunity to enjoy the stunning views of Doharsquos skyscrapers and be marvelled at
the unique Ras Abu Abod Stadium Its design concept results in a good cost-efficient arena with an
elegant curved square form
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images)
This innovative stadium will also allow it to be completely disassembled after the World Cup
Precisely many elements of the arena including all 40000 seats the containers and even the roof
will be reused providing valuable infrastructures to sports and non-sports projects elsewhere
Moreover off-site manufacturing can reduce emissions much more than conventional
method In 2009 Al-Hussein et al focused on the construction phase of modular and conventional
buildings and compared their CO2 equivalent emissions They analysed a 42-suite multi-family four-
story residential modular building located in Alberta Canada All the construction activities needed
for this building and a similar conventional building such as material delivery transportation
workforce trips equipment usage and winter heating were identified separately Therefore CO2
emissions from each of these activities were quantified The authorsrsquo analyses showed that modular
processes led to a 43 reduction in CO2 emissions compared to on-site processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
37 | P a g e
Table 2 4 - Environmental Benefits
While the on-site construction disturbs the sitersquos neighbourhood with noise dust congestion
and waste modular construction performs better by providing minimal project site disturbance
(Mohammad Kamali2016) Since most of the construction process takes place offsite there is less
impact on the project surroundings Modular construction reduces the number of vehicles and heavy
equipment required on site which translates into reduced pollution and less site disruption
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site (wwwcadoltocom)
Energy consumption in the occupancy phase of modular buildings dominates the other life
cycle phases This phase alone accounts for more than 70 and up to 98 of energy consumption and
consequent impacts over the life cycle of buildings while the contribution of the construction phase
is relatively small (M Kamali 2016) Sustainable material selection optimum modular factory
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
38 | P a g e
location and availability of labour which lead to less embodied energy consumption are effective
opportunities to reduce the life cycle energy consumption and the subsequent environmental
impacts In addition a smart design of insulation which is advanced in modular buildings can achieve
a high amount of energy use saving during the operation phase
Figure 2 44 - various layers of a module building unit including insulations (wwwsteelconstructioninfo)
Health and security benefits
When it comes to safety modular method can offer advantages for both phases (construction
and operation) to workers and future users Converting possibly dangerous on-site activities to an off-
site plant that there the supervision and control is much higher can reduce the accidents for the
workforces and the products It is obvious that the safety plan can be applied much more efficient in
a factory environment Not only is there a reduced risk of slips trips and falls ndash particularly as work
at height is reduced but there is also a reduction in onsite activity thus ensuring health and safety
always remains a top priority from start to finish
Furthermore if necessary factory operations can continue 247 with less risk of noise and
disruption to workers Work is also unaffected by the weather and other environmental delays which
could result in the project being turned around even quicker
On the other side during the operation phase safety can be improved for instance fire
protection can be designed by using multiple insulations and protectors inside the panels
One of the examples is Actavorsquos plan for Ensuring everyonersquos safety is at the heart of Actavo
what does and in line with this they have developed the HEART (Help Eliminate All Risks Today)
procedure Devised and implemented in the continuous effort to create an accident and incident-free
environment the HEART behavioural safety observation process sets the whole Actavo teamrsquos
expectation every injury is preventable so do not let any happen (Hannah Vickers b4edcom)
Modular construction generally achieves these requirements using fire-resistant plasterboard
conforming to BS EN 520 Alternative materials such as cement particle board and gypsum fibre board
may also be used in combination with plasterboard as the facing layer In residential construction
each dwelling usually forms a separate fire compartment All walls and floors that provide a separating
function between compartments require 60 minutes fire resistance In hotels and other residential
buildings each bedroom may form its own compartment (wwwsteelconstructioninfo)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
39 | P a g e
Figure 2 45 - Compartment floor at junction with external wall and compartment wall (wwwsteelconstructioninfo)
Social-Laboral benefits
Most of the mentioned benefits including economic scheduling environmental and safety
advantages have direct effect on social well-being as well Therefore they can also be named in this
section Future users can benefit from the quality of building energy savings etc which leads to
costumerrsquos satisfaction among the public Due to the shorter on-site schedule there are fewer
negative impacts on local businesses urban beauty image than conventional constructions Also
modular construction demands more skilled workforce and experts which can create more jobs for
these group of labour in the regions that struggle with high unemployment rates
In addition every industry needs to trust innovations in order to improve the science and help
the innovator to break limitations and explore new alternatives to solve problems Modular
construction as it was mentioned can be a great solution for the productivity problem in construction
industry and by applying these method it is possible to even find more solutions in the future which
can increase these rate more or solve other problems that nowadays are common among players of
construction industry Table 2 5 - Health and safety amp Social-Laboral advantages
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
40 | P a g e
Modular Construction role in COIVD-19 Pandemic
Recognizing the urgent need to create modular critical care units for rapidly growing numbers
of COVID-19 patients HGA Architects and Engineers partnered with Boldt Construction to design and
build a new system within a noticeably short timeframe ldquoThe initial idea was to provide rapid
response for hospitals and build a product with off-the-shelf readily available parts because we did
not know what the supply chain would be like Over the course of three weeks we went from concept
to full design and fabrication was underwayrdquo reports Ben Bruns executive vice president of Boldt
Construction in Appleton Wis (Rapid Response by Barbara Horwitz-Bennett 2020) The final product
was a prefabricated modular solution for assembling field hospitals capable of providing airborne
infection isolation rooms
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use inside convention
centres arenas and temporary structures Image courtesy of HGA and The Boldt Company (prismpubcom)
These Strategic Temporary Acuity-Adaptable Treatment (STAAT) units are isolation units with
enough clearance for safe bed transfers and accommodate equipment and a reclining chair These
multifunctional modules can be used as supplemental interior isolation rooms within an existing
system of care as a modular system connected to an existing hospitalrsquos infrastructure or as a self-
sufficient temporary hospital with its own infrastructure
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The Boldt Company
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
41 | P a g e
PCL Construction has come up with a similar solution in collaboration with Thor Plumbing and
Heating f-BLOK Architecture EH Price Industries and P4 Electrical Contractors Called ldquoQuaran-Tin
Podsrdquo the units are emergency response modular isolationcare rooms that provide temporary and
reusable emergency isolation for care and treatment of COVID-19 patients Each unit is self-contained
with built-in power heating and cooling as well as connections for medical gas oxygen and vacuum
Highly scalable and customizable the pod is continuously negatively pressurized and all the exhaust
is HEPA filtered Citizen Care Pod is a smart screening and testing pod that integrates intelligent
technology within a modular design to support a safe responsible recovery for governments
businesses and communities Customizable with the capabilities to enable full-on mobile COVID-19
testing in high-traffic environments the project will help in testing screening and eventually
vaccination on a mass scale (Christele Harrouk on archdailycom)
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction (archdailycom)
The Citizen Care Pod is a turnkey solution that accelerates recovery for businesses and public
institutions such as airports offices sports and entertainment complexes construction sites and
more by rebuilding staff and customer confidence that your organization is equipped to ensure their
safety
Unfortunately the COVID-19 pandemic is only intensifying the housing crisis Further
complicating the issue is the fact that a significant percentage of skilled labour workers will be retiring
within the next couple years which will significantly impact the construction industry As stated in
MBIrsquos ldquoThe US Construction Industry A National Crisis Loomingrdquo there are currently not enough
skilled workers to build all of the projects that need to be built in the same manner in which they have
been built in the past ldquoThere is no other choicerdquo advises Hardiman ldquoIt is now time for our
policymakers to start looking at alternative ways to build everything and we think that modular
construction should be a part of that solutionrdquo Along these lines the COVID-1 Response Page also
includes links to articles illustrating how MBI membersrsquo systems and facilities are currently being used
in housing infrastructure and COVID-19-related projects
Review on common challenges
Initial costs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
42 | P a g e
To start the modular construction method in an area there will be a significant investment
to establish a production plan and then designing team who must work alongside the execution
engineers parallelly in the design phase
factory cost Like any other industry modular construction demands a production line which
is an off-site plan with a supply chain based on 3D volumetric products First the off-site plan must be
designed based on the local requirements amount of demands availability of experts and labours and
budget that manufactures are willing to invest on this technology These factories are mostly
expensive to be build and the issue of production costs will always be a barrier to innovation in
modular construction because both the client and the architect will expect lower fabrication costs
However the art of every industrial innovative player is to study the economic pros and cons
of issued technology and then the industrial expert by doing couple trade-offs between the benefits
and disadvantages can make the decision whether to apply the new method or not Modular
construction is not an exception of this fact A local study can tell the investors if the approach would
be reasonable in all term and not only economic terms for the society or not Thus due to the
economic benefits that were mentioned earlier in numbers of regions which the labour salaries are
higher and the balance between transportation costs primary material access and costs experts
existence local market and their demand of real state and initial costs is more favourable modular
construction can be the best solution to apply On the other hand nowadays there are numbers of
region which the investors of industry are eager to use innovative method with higher costs that have
positive influence on environment and public health in which modular construction is more friendly
than the conventional method
Figure 2 49 -Balance between Initial costs and Economical benefits
First design costs and errors By changing the traditional construction products a change of
design is also demanded Modular design can be based by the production linersquos technologies the
budget of manufacturer and the final products quantity and quality In the earlier discussions about
design phase the complexity of 3D volumetric design had been mentioned and surely in the first
attempts would be expensive for the manufacturer However if the design could focus more on the
standardization of elements repetition in production line and consider integrate with modern design
software in order to provide more executive details and minimize the future errors and reworks the
rework cost can be eliminated and the design sample can be used for numbers of projects as a
catalogue with few changes Therefore by having these advantages the initial design cost can be
recovered soon and even make more benefit by the time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
43 | P a g e
Architectural challenges
One of the main group of experts who have argues about modular buildings are the
architectures who always suffer from limitations that this approach puts on their design process Most
of these challenges are mentioned below
bull Manufacturing technologies effect on the design One of the challenges which the manufacturers
can struggle is to consider a production line that be able to produce a wide range of product so
that there will be fewer limitations on the design phase This goal can often be impossible because
of the predicted budget of investors limited area of production plant and lack of technologies
Thus it is the architect who must be flexible with the production line and its boundaries
Moreover it is the art of the architect which can maintain a balance between ability of production
line and attractivity and innovation of the final product for the market and the industry
bull Transportation boundaries on architecture It is a fact that the transportation of modular
construction have puts limitations on the architectrsquos works The modules must obey the
obligations and regulations of the region that want to be transported in Therefore architects
must design modules which are transportable and minimize negative economic and timing effects
for the project In addition in the designing process environmental aspects which can be
happening during the transportation phase must be considered
bull Regional architecture specializations There are cases in which an off-site production plant ships
same model of modules for numbers of projects which are going to be assembled in variety of
regions with different climate cultural architecture and local construction regulations which can
surely have negative effects on the regionrsquos construction industry real estate market and cultural
architecture aspects For instance the harmony of the angel of sunlight and the windows
formation and dimensions in a residential building located in eastern region and western ones
which reduce or increase the sunlight absorption inside the building for the residents In this case
if the same form of modules will be transported and assembled without of any changes the
unsatisfaction of future users can be increased and in a result the demands can be reduce
significantly which could cause a failure for the real estate and construction industry of the region
In terms of architectural culture modular manufacturers must consider the traditional
architecture of the location in the designs in order to make sure that the harmony will be kept
among the present buildings and modular ones
bull Lack of knowledge about modular buildings among architects Manufacturers argue about the
lack of enough knowledge of architects about the modular fabrication process The third-party
inspections and approval process Transportation methods and its boundaries Onsite assembly
procedures The cross section of a modular structure which can reduce their understandings from
manufacturerrsquos demands of project and result a unsuitable design for the final products These
disagreements come with every innovation in civil engineering society which architect must follow
their lead most of the time The solution for this cause is to educate the architects by planning
workshops by the manufacturers or internships during a project so that architects can improve
their knowledge and gain actual experiences by observe and participating in real projects
bull Unfeasible on-site finishing Common architectural innovative designs focus a lot on finishing
works in order to gain attentions of buyer and improve attractiveness of buildings There are
different views about this subject Some manufacturers think that the finishing process must be
as simple as possible or minimize the schedule and costs on-site to benefit from the project On
the other hand architects believe that the modular buildings are not attractive enough because
of repetition in their design and try to focus on finishing process to make them desirable to the
market or improve the products in architectonic point of view
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
44 | P a g e
Transportation challenges
By transferring most of the construction activity to the off-site plant transportation plays a
vital role in the projects so that in case of poor logistic management can damage numbers of benefits
which were achieved in the factory plant
bull Dimensional and weight barriers based on type of transportation The type and technologies of
every modular constructorrsquos logistics can affect the project from the design phase to the on-site
assembly These effects can change the dimensions weight and structural features of the product
For instance modular structures transported on a flatback trailer will be limited in length width
and weight based on the physical capacity of the truck Components fit into shipping containers
are best suited for projects overseas because the structural integrity of the containers allows for
unorganized stacking However components will be limited by the interior dimensions of the
container in length width and height (Joseph M Schoenborn 2012)
bull Long distance transportation and lack of existence of local factory Off-site plants are not
available for every site location in numbers of states or even regions yet because of poor
development of these method in those regions Therefore in some cases the modules must
shipped even overseas to the site location to be assembled Long distance and its possible
difficulties during ground or marine transportation can bring extra costs for the project which
must be studied economically before the biding process
bull State regulations on structures dimensions and strategic issues Estate laws can always put
boundaries on construction industry and modular constructors are not an exception Every region
has its structural and transportation regulation which limits the final product In addition estate
approval during transportation phase can harm the projectrsquos scheduling program and put delays
on the arrivals or even occasional penalties which causes extra costs in the budget
bull Negative effects from environment on the modules during the transportation While the
modules are being transported to the site these products are in direct exposure to the
environment such as sunlight rain wind and other natural causes By the time possible damages
can be appeared in the modules which in some cases can be too critical that module need to be
repaired or replaced to be used On the other hand ground transportations can cause vibrations
on the trucks and its loads and the intensity of damage generally increases with the roughness of
the road surface which in some creates cracks or more critical damages on the structural element
installations or finishing The solution is to use To minimise transportation difficulties the vehicle
having vibration absorber can be used to minimise damage due to vibration and additional
precautions need to be considered for wider modules while low bed transport vehicles are
preferable for transporting taller modules (W Ferdows 2019) Moreover loading and offloading
processes must be carefully done by precise strategy and adequate equipment in order to avoid
the harms on the products
bull Transportable materials There are two terms which force modular constructors to use advanced
and high-quality materials transportation and design situations Transportation as it mentioned
earlier puts limitations on the final product and force the constructors to use material which have
less weight more against resistance road vibrations and endurance against sunlight and humidity
exposures In one word these materials must be part of a final product which can be
transportable Often these materials add costs on the project because they are more expensive
than the ones which have been used in conventional buildings All properties need to be
structurally sound in situ but units built using offsite construction methods also need to be
structurally sound whilst being raised and lowered throughout the transportation and assembly
stages of the process Key structural elements such as beams columns and potentially walls and
floors must be repeated in three-dimensional modules for transportation purposes This can
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
45 | P a g e
significantly increase material costs depending on the material choice and level of design
optimization (McKinsey amp Company 2019)
On the other hand numerous benefits which modular construction has in terms of material
such as less reworks discount on massive offers no exposure to natural causes and its off-site storage
and less waste during the production can assure the constructors that these challenges can overcome
the fact that modular buildings work better than conventional ones in a material criteria
Wrong perceptions among public and real estate market
Innovation without correct publicity brings wrong perception among people and markets
Also errors bad experiences of users and unprofessional works can change the mindsets quickly by
unsatisfying the users and in result investors During a period in past off-site accommodations were
mostly for temporary uses with low quality material and less functional features The demands of
permanent housing raised after a break such as world wars for those who lost their houses and
refugees that wanted to live abroad Therefore numbers of companies started to modify their off-site
products in order to have more lifetime and serviceability However there were constructors who
could not provide buildings with better functional services and the users became unsatisfied and lost
their trust in these products This wrong perception had been raised even until now that off-site
building such as modular ones will not serve a long lifetime and have low quality material incommode
and unattractive design and a poor functionality Obliviously bad perception of people will reduce the
demands and destroys the market as well
Today the industry recognizes the need for durable construction for even temporary uses
making it possible to move and re-use full buildings So a lack of knowledge among consumers as to
what is possible can prevent design innovation In order to overcome the stigma sometimes associated
with modular construction manufacturers attempt to offer a built product indistinguishable from one
built onsite Therefore the industry advertises a direct alternative to onsite construction In a
comparative analysis of the two processes time savings and worker safety stand out as the primary
advantages of modular construction over onsite construction The building manufacturing process
itself construction in a controlled environment with access to advanced technology is an evolution
of the art of building which is traditionally slow to evolve The modular building industry therefore
should advertise a different building product altogether featuring design innovation and ingenuity
executed through advanced building techniques (Joseph M Schoenborn 2012)
Moreover in order to raise the demands among the public who can be future users a range
of positive publicity about the environmental advantages such as less emission economic savings like
less energy bills cheaper and easier maintenance processes during the operation phase and faster
construction process which help them to be accommodate sooner can create a positive mindset
among the public In addition post-sell services from constructors such as better assurance policies
for buyers maintenance services and offering loans to customers who are in emergency
accommodation needs can change the market significantly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
46 | P a g e
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects (casasinhauscom)
Integration of advanced software
As it mentioned before modular construction can benefit from using innovative software in
their designing phase in order to be more precise on planning and provide detail for the production
line One of these software programs is BIM which can be used in design construction phase on-site
assemble and even operation phase However despite its advantages there will be some challenges
as well The greatest challenge of using BIM in construction project is the implementation process
itself regardless of the software capabilities Development of accurate BIM model requires extensive
resources and in-depth knowledge of construction methods and process Most small or medium firm
could not afford the special team and man hours to aligning BIM (Na Lu and Thomas Korman 2010)
Other than finance and organizational issues the project team has experienced legal challenges as
well The use of BIM technology encourages multi-disciplinary collaboration which contrasts to
defining responsibility to each party and then assigning liability issues among the parties In addition
using BIM models instead of traditional contract documents raises questions on insurance coverage
and confidentiality exposure Ownership and control of the model use and distribution of the model
and intellectual property rights are some of the issues that need to be addressed while BIM
implementation being adopted in construction industry
Redefining the contracts
Due to the changes over the responsibilities of every participants the amount of their
influence on projectrsquos activities and transferring most of the work to the off-site plant a new way to
contracting is needed in order to optimize the relationship between the owner designers and
manufacturers during all phases of the project Here are some of the common types of contracts which
are being used among modular building industry
bull Design-build The architect modular manufacturer and onsite general contractor are
hired as a team and assume the responsibilities of design and construction together DB contract can
be named one of most traditional types of contracts that would create an integration between all the
parties of a project Due to the design-build nature of modular construction a close partnership is
demanding during the project phases
bull Design-bid-build After the architectrsquos design has been approved by the client a
competitive bidding process takes place This results in a greater disconnect between parties The
common gap between participate happen a lot in this type of contract which frequently can cause
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
47 | P a g e
misunderstandings about responsibilities of each expert incomplete information about the project
design or executive details and lack of transparency among the participants
bull Negotiated bid The modular manufacturer is hired first by the client to find the
appropriate architect and onsite general contractor that can be hired within the constraints of a
budget This concept may increase bonding between experts and improve everyonersquos understandings
about many aspects of the project But the budget will decide whether the quality level design
enhancement can meet the clientrsquos requirements or not In addition in case of clientrsquos approval the
question would be the future userrsquos satisfaction can be achieved or not due to the budget limitations
on the project quality level
bull Certified Modular Architect (CMA) A sustained relationship between an architect
and a manufacturer can be developed over multiple projects Therefore a certification process
providing training and continuing education can be introduced to the modular building industry An
architect intimately familiar with modular construction is best suited to handle coordination issues
that arise when work is being done in the factory and onsite simultaneously A it mentioned earlier
architects understanding and knowledges is critical to avoid possible mistakes and unsuitable designs
for modules Therefore this certified education which can be called as a semi-professional internship
for the design team in order to be present at every phase of the project
Supply chain-transportation-onsite assembly management errors
One of the main objectives to use prefabricated elements in construction is to raise the
productivity in execution phase which is mostly happens in off-site plant As it mentioned before there
is a supply chain in manufacturing plant and its productivity is depended to many key factors which
will happen outside of the factory Continuity of assembly operation is one of them which would be
happening in parallel with off-site supply chain After the modules were prepared to be transported
to the site the transportation system must be synchronized with the factory delivery and assembly
demands If any delays may happen during the transportation would affect the both origin and
destination scheduling storage policies and demands
On the other hand assembly line also must on-time and well-communicated with off-site
plant experts because any changes in execution phase can make huge negative impacts on supply
chain productivity Therefore these three important phases must plan based by on-site demands
supply chain productivity execution management and transportation systems
Figure 2 51 - synchronization between supply chain transportation and on-site assembly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
48 | P a g e
3 Common challenges in modular construction industry by a
survey Methodology
Objective
This study used qualitative research and specifically a grounded theory methodology to
uncover more information about advantages of modular construction and its constraints or barriers
to develop this method in the market Qualitative research emphasizes the influence of the researcher
on the data collected
Role of the researcher
In this study I acted as the sole researcher who was responsible to design questions based by
literature reviews and then by creating an online survey form try to collect the data from the
participants
Ethical considerations
To protect the rights and guarantee the safety of participantrsquos information following actions
were done
1) The research objective and process were made clear to the participants
2) The collected data was used for research objectives only
3) Only eligible participants who are modular constructors and manufacturers were
chosen for this survey
4) The access option to the survey information gave to the participants after the
research was finished
5) The anonymity of the participants was maintained
6) The name of the participant and their brand was remained confidential for all roles
even the researcher to obey the law of data protection
Survey setting
Due to the emergency restrictions which caused by a virus pandemic across the world several
options were unavailable to be done such as face to face interviews factory visits and project site
practices Therefore online interview was the only solution which can be happen without any danger
for participants and researcher In most regions construction companies are suffering from a full shut
down on their production line and on-site projects so that access to these participants became even
harder than usual Thus an online survey form by office forms was chosen for this research so that
the participants can answer the form questions at any time and location with ease to answer by
multiple accesses to the formrsquos link (Figure 31)
This survey forms had been sent by email to the official addresses that were mentioned in
their websites for contact The priority in choosing the recipients were the construction managers
project managers and executive engineers so that the information will be collected from the operation
managers who have the most technical experience and have the most knowledge with construction
phases from off-site production to on-site installation This could also help the survey to find the
challenges during the construction that were not able to be visited due to the restrictions of global
pandemic
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
49 | P a g e
Figure 3 1 - Online office forms for survey use
The estimated time was reduced to 13min with the most important questions to improve the
efficiency and be timely reasonable for the participants
Development of questionnaire
After hours of study on numbers of articles which have focused on challenges in modular
construction industry several were found that have lack of scientific scope and recommended
solutions Therefore many of the questions were designed to first shed a light on the potential
advantages which have not been mentioned specific and completely unknown for the industry For
instance the social benefits which came immensely useful during the COVID-19 pandemic for health
centres and medical infrastructure etc Moreover a lack of inconsistency between industry and
science came to notice which shown a massive gap between these two important roles in construction
industry This gap explains that the scientific researchers in some areas have the minimum contact
with industrial players in construction world in comparison with other industries which the opposite
situation is applied To fill this gap questions were designed in a way which have an origin of scientific
researches and direct and first-hand information from the construction industry players which are
constructors modules manufacturers etc
Development path of questions can be explained as critical path to the best details of each
criteria than can obtain useful information from participants In terms of advantages the benefits
which were identified from literatures were ordered and asked form participants to be confirmed and
validated by the industry players in real project cases For instance in an environmental point of view
Reduction in Energy Consumption was identified in literatures and had been asked among participants
to confirm the hypothesis that modular construction can reduce the energy consumption in
comparison with traditional methods (Figure 32)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
50 | P a g e
Figure 3 2 - Questionnaire development
Participant profile
Experience amp professions
As the ldquoTable 31rdquo explains information from five companies have been selected for this
survey with variety of backgrounds from pioneers to well-experienced players in industry with over
than 120 years of experience in the modular construction society as constructors and modular
manufacturers The experts who answered have different roles in the industry from CEO to architect
and sales managers so that the data can have more perspectives of views on the questions such as
sales market and design process to project management Table 3 1 - Participantrsquos profiles
Because of diversity in the influence of challenges between massive international builders and
local players these five companies responds have been compared to each other from company C
which is a local constructor to company E that is currently executing modular projects in 80 countries
with approximately 6000 modules build annually
Types of materials in some cases can have different statistics in results For instance in
modular construction which steel and wood modules are more often used in projects can produce
various amount of CO2 emissions and waste or recycle process can be done with more ease For that
reason these survey all types of materials are considered including steel modules concrete modules
and wood modules There is also an argue that some benefits and challenges cannot be seen in unique
projects with more repetition in production of elements and mass production such as hotels and
schools while in residential projects can exists more than the others To cover all the contrasts of
60 of participants
can acheive a 30-40
reduction energy
consumption
A Our homes are not positive from an energy
perspective
B We can finish a 4 months traditional project in 8-10 weeks and Energy consumption of a factory is known and relatively constant on a weekly
E 30 reduction in energy consumption
Modular construction can
reduce the energy consumption up
to 30 in compariosn with
conventional methods
QsCompany A B C D E
Years of company experience 10-15 10-15 20-30 20-30 30-50
Position of participant CEO Sales Manager Design Architect Quantity Surveyor Foreign Trade Manager
Professional experience 15 13 30 NA 3
No of employeesfactoryModules build annually 801200 1301490 151- 50280 25026000
Type of material(WoodSteelConcrete) W amp S W W W S amp Conter amp fiber cabins
Types of Projects (ResedentialSchoolsHospitalCommercial) R R amp S amp C R R amp S amp C amp H R amp S amp C amp H
Use of BIM Yes No No No No
Level of automation 20 reaching up to 80 20 Off-site 60 On-site 20 20 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
51 | P a g e
information these companies have been selected that are involved in all types of modular building
projects including residential hospitals schools and commercials buildings
As it mentioned before BIM program can advance the projects in many ways however
unfortunately among these participants only company A is able to benefit from this software from 0
to 100 of the project Therefore the further arranged interview focused on BIM Function was
cancelled and may be done in the future investigations
Automation can play an important role in improving the productivity and sustainability of
construction processes as a part of ldquoindustrialization in constructionrdquo movement Among survey
participants the minimum automation level in off-site plants is 20 and maximum of 60 and in on-site
activities can be up to 40 In addition company A claimed that in near future their automation can
reach up to 80 which is an innovative move in construction industry On the other hand company
with over than 6000 modules build annually have a significant 60 of automation in their plant which
shown a massive interest of investment on this technology In addition automation application
difficulty have direct relation with the type of materials used in modules and type of the projects which
as Table 31 illustrates company E with the most variety in project types and materials use have
achieved a huge success in application of automation with a level of 60 which also helped a lot to
expand their market overseas
Data collection
General information
All the received information has been attached in ldquoAnnex 1rdquo where the responds are not
edited and mentioned in the original shape Here are the shorter versions of responds
bull Motivations to choose modular construction over traditional
To bring the attention of investors to an innovative method reasonable motivations are
needed which can be the current demands of market economic profits and environmental benefits
Therefore it was necessary to identify the motivations of these companies to start a modular
construction form Economic advantage for most of these has a priority not just for being profitable
but for being able to develop their dominance in the future On the other hand innovation has an
approximately same amount of interest which explain the reason behind choosing modular method
that is one of the most innovative off-site construction methods in the industry
The fact that mentioned before in literature reviews high demands in the market and the lack
of provide by construction players is one of most important reasons to apply a fast and high-quality
solution for reach the satisfaction of housing market Shorter schedule and environmental benefits
took the next places of priority in motivations for these companies which are also important for sure
Figure 3 3 - Participants motivations to start a modular company
28
9
18
18
27
Economic benefits
Enviromental benefits
Shorter schedule due to the need
High demands of housing in themarket and lack of provide
Innovation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
52 | P a g e
bull Built in factory panelssubcontracted panels used in modules
All five companies are manufacturing the panels that used in modules by their own inside the
off-site plant which as it mentioned earlier the selected participants have a variety of production rates
and by this information that they are able build their own panels it can be said that their production
is 100 off-site However in the case of company E which is a massive international modular player
there are some types of modules that are being provided from domestic market because of economic
feasibility issues
Economic issues
bull No of labourLess wages of salaryAdded value in each hour of workneed of
special workforce
Generally the participants mentioned that there fewer number of workers are needed on and
off site in comparison with traditional method About the amount of salary wages company A
confirms that for each hour of work off-site less amount wages are being paid to workers On the other
hand the shorter schedule of projects in modular projects can reduce the payments as well The fact
that most of the participants are emphasizing is that the efficiency of work and added value of
activities off-site are much more than the on-site traditional projects where company A acclaimed
that in terms of efficiency ldquo1 hour in the factory is equal to 4 hours on-siterdquo
Environmental status
bull Life cycle duration of products and material recycle
Company B acclaimed that they do have multiple solutions for each materials that theyrsquore
using in their modules for instance the unusable drywalls and PVC materials which they send for
recycling or the woods that would use into mulch products or for heating by others
Company E told that their products have a 50 years life span which is the same as a lifetime of
traditional build residential house However company C have some difficulties in recycle and reuse of
their elements because of unportable feature of their products
bull Integration the modules with other innovative technologies
Four of these five companies confirmed that their products have the option to integrate with
other innovative technologies such as self-powered homes by solar panels and also using advanced
insulation technics made by non-petroleum materials in their panels to reduce the energy
consumption during operation phase
bull Waste reduction
Company A acclaimed that their production line generates significant amount of 70 less
waste in comparison with traditional method The rest of the companies focused on carbon footprint
reduction and were able to reduce it 15 less that traditional method by choosing environmentally
friendly technologies in production and wise choice of materials for their products
bull Reuse of structural and non-structural elements in projects
Three of five participants confirmed that they have the ability to re-use their products in the
next projects in order to reduce the waste and energy consumption during the manufacturing
processes Type of the projects and material have the direct relation with the potential of reusability
in elements and due to the variety that the participant have in both criterions the potential is variable
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
53 | P a g e
Figure 3 4 - Re-use potential
bull Reduction in Energy Consumption
Company E mentions that modular construction can achieve a 30 of energy saving in
comparison with traditional site-build method while company A acclaimed that their homes are not
positive from an energy perspective Company B gave more details on energy consumption by making
a comparison between off-site activities and on-site traditional construction and acclaimed that due
to the shorter schedules in off-site production energy consumptions can be reduced up to 50 They
mentioned that ldquoEnergy consumption of a factory is known and relatively constant on a weekly
monthly and annual basis A competent and experienced modular builder can many times finish the
entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-
built house could require as much as 4 months for the same completionrdquo
Social Benefits
bull Delivery of projects for emergency services during COVID-19 Period
As it mentioned earlier due to the virus pandemic that is happening at moment in all around
the world a rapid response is needed more than ever for emergency services for health organizations
and according to this survey one of these companies is providing products for this cause which can be
a good news and accounted as a social benefits for this method of construction
Figure 3 5 - Contribution in Covid19 epidemic
bull Providing post-sale services for clients
In contrast with conventional construction which just have the responsibility until the delivery
of the project modular constructors because of their industrial profile have the ability to offer post-
No40
Yes60
Reuse the structuralnon-structural elements projects
No
Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
54 | P a g e
sale services to the clients such maintenances upgrades etc due to the results of this survey four of
these five companies confirmed the availability of post-sale services for their clients
Figure 3 6 - Post sale services por future clients
Initial costs
bull Initial investment and its Payback period
Company A claims that their initial investment to establish their company was about 20 million
Canadian dollar and its payback period was 5 years Company E had the amount of 15 million USD with
the same 5 years period However company C like many of the older players in modular construction
industry who started way earlier cannot estimate their initial investment
bull Factors that can change the initial costs
There are factors which can make a change in initial costs of companies The participants
prioritized these 6 chosen factors starting with product types and production range with 31 of
importance among others Level of automation took 25 share of the pie chart which has direct
relation with the initial costs Off-site plantrsquos location has 19 of efficiency on starting costs and
furthermore the quantity of sub-contracted players in the projects achieved 13 of the graph Finally
financing and design enhancement have the minimum equal shares of 6 which despite of being the
last factors have the efficiency on initial costs as well
Figure 3 7 - effective factors in initial investments for start-up companies
6
25
31
13
19
6
Factors that effect on initial costs
Design enhancment Level of automation
Product types and production range Less sub-contracted
site location Financing
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
55 | P a g e
Design limitations
bull Design boundaries caused by production line
Company A mentioned the subassemblies as the main element to be considered in design
phase while company D and company B introduce a maximum dimension for their production lines to
be economically viable for transportation costs In addition to those company C and company E
confirmed that there are no boundaries for the designer caused by the production lines because of
their wise choice of prefabrication methods
bull Lack of knowledge from architectsdesign engineers about production processes
transportation limitations etc
One of the main problems of start-up companies and the experts who join the modular
construction industry is the lack of knowledge about off-site processes and transportation limits
Three of five participants confirmed that there is lack of knowledge in these area from designers
Figure 3 8 - Lack of knowledge among designers and engineers
Transportation Limitations
bull Transportation regulation effects on modular projects
Three of five participants confirmed that the regulation by transport administrative can be
harmful for the projects such as extra costs or time delays on schedule Company A mentioned the
time delays in giving permits to the manufacturers and constructors which can damage the
synchronization between production line and on-site installation by reducing the speed of
transportation of elements to the site Company B added information about transportation system of
some states in America which use the term ldquoSuper Loadsrdquo to put limits on oversized shipping that
increases the cost and time on the project On the other side Company C as a strategy to avoid this
problem used legal load limits in their design instructions so that their products will obey the
regulations
bull Transportation boundaries on material choice and project costs
Company B D and E confirmed that the terms of special transportable material will not add
extra costs on the project Company A acclaimed that the extra costs by transportation can be offset
by speed of production and reduced financing costs for the project
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
56 | P a g e
Project management challenges
bull Difficulties in using automation in off-site production
In this survey based on literature reviews 4 main reasons for difficulties of using automation
in off-site production were selected to ask the participants Integration with advanced software and
high expenses of application in production line took approximately 60 of importance among others
Codding problem is another major problem in this subject which have 28 of pie chart In addition
company A demanded ldquoAn international coddingrdquo as a solution for this problem The last section
belongs to ldquolower salaries of manual processesrdquo which has the minimum importance of 14 among
participants
Figure 3 9 - challenges of using automation in off-site plants
bull Contracting problems
Starting with company A which acclaims that every state has its own code and the lack of a
universal code can bring challenges for modular players
Company B explained about the misunderstanding by final client who is the end home buyer
who ldquobelieves the factory to be the builder and the actual independent builder to be a sales agent
for the factoryrdquo Their recommended solution for this problem is to define the relationship between
the participants of projects their responsibilities by social media and requiring the builders customer
to sign a disclosure acknowledgement from that describes the relationship in detail
Company C mentioned a financial challenge caused by the banks in the projects that are
financed by them (Banks) which do not consider the project done until erected on-site This issue
creates pressure on cash flow of project where bank finance is involved The only problem that
company E consider in terms of contracts is lack of timing on project delivery which is generally causes
by constructors or general contractors
bull Lack of synchronization between projectrsquos participants
To begin with company A believes that there is a lack of quality partners on site They explain
that the problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution Company B mentioned that the responsibility of ensuring
28
29
29
14
Difficulties in using automation in off-site production
Codding Integration with advanced software Cost Lower salaries of manual processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
57 | P a g e
that the work is done properly belongs to the builder which any ldquodelays in this can result in postponed
transport of product and interest through demurrage charges
bull Sub-contractor for site planning and foundation phase
Company A uses local subcontractors for their site planning and foundation phases because
of variety of locations of their projects and ease of using local subcontractors Company B have only
the responsibility of modules production and defines the customer (the general
contractorindependent builder) responsibility to execute rest of the project phases have sub-
contractors if needed Company C does have sub-contractors for site-preparations and foundation
phases under direct supervision and the reason to not performing by their own is the high costs of
required equipment and not being portable for each project
bull Technology gap between sub-contractor and modular constructor
The only issue that were mentioned by participant is where company A recommended to ldquoto
educate most local subs on our process and reason for doing things a certain wayrdquo
Company B and C acclaimed that there are no challenges for the off-site production
Social challenges
bull Wrong perceptions among public and market
The only value that the market considers choosing modular method over traditional
construction is to be cheaper Company A says
According to company B experience in USA majority of people the media and even
professional engineers do not understand the capabilities of modular construction Many people
continue to confuse this form of construction with HUD on frame products
Another wrong perception that the publicmarket believes is that the prefabrication methods
limits the design options while Company C believe confirms that the reverse is the case
bull Solutions for resolving the wrong perceptions
Company A believes by using one of the main advantages of modular construction which is
shorter schedule the market can be dominated by modular projects and the more cases they deliver
the more recognised this method would be among the public and at the end the superior nature of
modular approach can be proved Company B addresses a solution in a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Company C acclaimed that advertising the modular advantages
among the public would be enough
Data analysis amp conclusions
The data from this survey can be used as an input data and prioritizations for the next chapter
which is decision-making process between four alternatives The solutions and recommendation will
be repeated at the recommendations at the final chapter as well Here are the conclusions about
advantages and challenges in modular construction mentioned by professional participants
Advantages
Economic benefits Generally apart from the other benefits as the participants mentioned
that there fewer number of workers are needed on and off site in comparison with traditional method
and Due to the shorter schedule of projects in modular projects can reduce the payments wages
Other fact that most of the participants are emphasizing is that the efficiency of work and added value
of activities off-site are much more than the on-site traditional projects
Environmental benefits Due to the variety of solutions for each material that they are using
in their modules there is high potential to send the used elements for recycling or would use into
mulch products A long lifetime span is acclaimed for the products which is close to the traditional
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
58 | P a g e
ones Majority of participants confirmed the literature concept that their products have the option to
integrate with other innovative technologies such as self-powered homes by solar panels and also
using advanced insulation technics made by non-petroleum materials in their panels to reduce the
energy consumption during operation phase In the waste management term there is a possibility for
production lines to generate significant amount of 70 less waste in comparison with traditional
method Moreover about carbon footprint reduction there is ability to reduce it 15 less that
traditional method by choosing environmentally friendly technologies in production and wise choice
of materials for products While there is argue that modular construction can achieve a 30 of energy
saving in comparison with traditional site-build method there are claims that their homes are not
positive from an energy perspective However this idea mentioned that by making a comparison
between off-site activities and on-site traditional construction due to the shorter schedules in off-site
production energy consumptions can be reduced up to 50
Social benefits As it was mentioned in literature reviews there are social benefits in modular
construction that can improve the satisfaction of clients Post-sale services for customers are possible
which is completely opposite to the traditional projectrsquos conditions
Challenges discussion
Initial costs It is obvious that a high amount of investment is needed to stablish an off-site
plant to start prefabrication of construction elements but the payback period is not that long that put
boundaries for start-up future players due to the collected information There are factors which can
make a change in initial costs of companies that are prioritized by the participants starting with
product types and production range level of automation which has direct relation with the initial
costs Off-site plantrsquos location the quantity of sub-contracted players in the projects and finally
financing and design enhancement have the minimum equal shares
Financial aids Financial assists which are crucial for kind of projects that are dependent to
these aids are not harmonized with modular project processes where there are argues that until the
first deliveries of elements to the site location and their assembly these aids are not reachable This
issue creates pressure on cash flow of project where bank finance is involved Changes in contract
conditions and education for financial supporters are recommended solutions to improve the
partnerships in projects
Design boundaries it was mentioned the subassemblies as the main element to be
considered in design phase while some players introduce a maximum dimension for their production
lines to be economically viable for transportation costs However there a possibility to eliminate the
boundaries for the designer by the production lines because by wise choice of prefabrication product
types
Lack of education The idea of lack of education among engineers and architects about off-
site construction methods was proved by the collected information which have to be resolved by
updating the education resources to innovative methods that can improve the productivity rates and
sustainability
Transportation regulations negative effects it is confirmed that the regulation by transport
administrative can be harmful for the projects such as extra costs or time delays on schedule Time
delays in giving permits to the manufacturers and constructors which can damage the synchronization
between production line and on-site installation by reducing the speed of transportation of elements
to the site A strategy to avoid this problem used legal load limits in their design instructions so that
their products will obey the regulations
Choice of transportable material effect In contrast with literature review which mentioned
the idea of extra costs by choices of transportable material this survey confirmed that the term of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
59 | P a g e
special transportable material will not add extra costs on the project Moreover the extra costs by
transportation can be offset by speed of production and reduced financing costs for the project
Automation use challenges Integration with advanced software and high expenses of
application in production line took approximately 60 of importance among others Codding problem
is another major problem in this subject In addition ldquoAn international coddingrdquo was mentioned as a
solution for this problem Every state has its own code and the lack of a universal code can bring
challenges for modular players ldquolower salaries of manual processesrdquo has the minimum importance
Defining responsibilities boundaries There is a misunderstanding by final client who is the
end home buyer who ldquobelieves the factory to be the builder and the actual independent builder to
be a sales agent for the factoryrdquo Their recommended solution for this problem is to define the
relationship between the participants of projects their responsibilities and requiring the builders
customer to sign a disclosure acknowledgement from that describes the relationship in detail
Lack of partnership among projectrsquos participants There is a lack of quality partners on site
The problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution The professionals answered that the responsibility of
ensuring that the work is done properly belongs to the builder which any ldquodelays in this can result in
postponed transport of product and interest through demurrage chargesrdquo
Wrong perception of publicmarket The only value that the market considers choosing
modular method over traditional construction is to be cheaper while majority of people the media
and even professional engineers do not understand the capabilities of modular construction Many
people continue to confuse this form of construction with HUD on frame products Another wrong
perception that the publicmarket believes is that the prefabrication methods limits the design
options while some players believe that the reverse is the case Therefore by using one of the main
advantages of modular construction which is shorter schedule the market can be dominated by
modular projects and the more cases they deliver the more recognised this method would be among
the public and at the end the superior nature of modular approach can be proved Another solution is
a form of cooperation between builders manufacturers architects and engineers to educate the
public by national entities such as Modular Home Builders Association
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
60 | P a g e
4 Decision making based on potential advantages among three
modular alternatives and conventional construction method in a
project by MIVES software Methodology
Objective
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria potential benefits can be recognised However to find out how much practical these benefits
are in the market several trade-offs must be done by professional tools such as project management
software programs which can take decisions based on the input data that receive
The objective of these thesis is to examine the practicality of modular construction by taking
the best decision among 4 alternatives including a conventional armed concrete building with steel
modular concrete modular and timber modular methods and see that the mentioned advantages can
lead the methods to become the best option to choose for building the project as a project
management point of view
What is MIVES
In order to make the most sustainable and reasonable decision among the alternatives a multi-
criteria decision-making program was used called ldquoMIVESrdquo MIVES is the acronym for Modelo
Integrado de Valor para una Evaluacioacuten Sostenible which means Integrated Value Model for a
Sustainable Assessment It is a multi-criteria methodology for decision making It allows transferring
the different characteristics of the objects to be evaluated to a series of homogeneous and
quantifiable parameters which facilitate the objectification of the choice
The MIVES methodology consists of creating a model that defines all the characteristic
features of the elements to be evaluated assigning them a function that allows converting the
different peculiarities of the alternatives into a common unit which we will call value Once the
amount of value for each alternative is obtained it can be used for a sustainable evaluation
(wwwdecaupcedu)
Data collection process
Case Study references
bull Journal of Cleaner Production (WAHammad 2019)
(httpsdoiorg101016jjclepro201904150)
This Fabolous multi-criteria comparison was done between two methods of conventional and
steel modular building in two cases case A which is a normal residential building and case B a school
building to measure the sustainability level of them in economic environmental and social areas The
location of this was considered in Sydney and central coast Australia and four BIM models had been
designed for each alternative in both cases The total floor area of Case A is 63 m2 (87m x 72m)
When adopting modular construction the granny flat is designed from 2 modules each module is
36m x 87m Case A was chosen as the study case to focus on because of type of the project that is
residential building
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
61 | P a g e
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study (WAHammad 2019)
The purpose of this journal is to add sustainability criteria as main factors for constructors to
make a multi-dimension decision whether to use Modular construction for a project or continue with
conventional methods
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and conventional methods
(Akbarnezhad 2019)
bull A comparative life cycle assessment (LCA) of concrete and steel-prefabricated
prefinished volumetric construction structures in Malaysia (Ali Tighnavard
Balasbaneh 2020)
(httpsdoiorg101007s11356-020-10141-3)
This researchrsquos focus is to compare two types of volumetric modules function in terms of cost
and LCA factors such as Greenhouse emission etc on a residential project with the approximate area
of 105m2 located in Malaysia based on local regulations Prefabricated Concrete Modules (PCM) and
Prefabricated Steel Modules (PSM) were considered for this project Recently Malaysian
administrative system has been pushing the companies and researchers to investigate on these types
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
62 | P a g e
of construction methods in order to measure the benefits and obstacles of using them in future project
and try to resolve the productivity problem in construction industry The construction industry in
Malaysia has been labelled ldquounproductiverdquo for its reliance on a large labour force and its use of non-
prefabricated strategies at a proper scale (Balasbaneh 2020)
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020)
bull Modular vs Conventional Construction A Multi-Criteria Framework Approach
published at ISARC 2017 (AWA Hammada and A Akbarnezhad 2017)
This paper did a comparative analysis in cost time and carbon emissions by BIM models
Material and equipment libraries and existent databases on a project in the North-West of Sydney
involves the construction of a granny flat with dimensions 14 m by 16 m
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017)
The framework of this papers based on the BIM model analysis with input data project actual
projectrsquos budget material and equipment used in the construction and environmental information in
database and then a comparative study on emissions during constructionmanufacturing schedule
and costs of project for crew material and equipment (Figure 45)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
63 | P a g e
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad 2017)
bull Life cycle greenhouse gas emissions and energy analysis of prefabricated reusable
building modules published on Energy and Building (Lu Aye 2011)
(httpsdoiorg101016jenbuild201111049)
Aye and his team did a LCA study on three alternatives PSM PCM and PTM which were used
in a multi-residential building with 63 apartment units with area of 63 m2
Figure 4 6 - Architectural section of multi-residential building (Aye 2011)
The modules in this study were categorized in 4 main elements Exterior walls with insulation
panels Interior walls used for internal separation which mostly build with timber frames and plaster
boards Floors with plywood material on topping in all alternatives and ceilings with thick plaster
boards and steel concrete and timber parts as main elements (Figure 47)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
64 | P a g e
Figure 4 7 - Structural elements used in modules (Aye 2011)
bull Comparing Environmental Impacts of Building Modular and Conventional Homes in
the United States published at Construction Matters (John Quale 2012)
(httpsdoiorg101111j1530-9290201100424x)
Quale did also a comparative analysis focused on Environmental emissions on two PTM and
Conventional Timber building Three residential modular companies generally representative of the
eastern US modular industry supplied data on completed projects for this study including utility
bills worker commuting information building materials and waste procedures construction
schedules employee schedules and other relevant information (Quale 2012) 186 m2 two-story
home that is a model for one of the companies involved in the study
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
65 | P a g e
Input data
4221 Alternatives
Four alternatives were selected for these study which are one conventional armed concrete
(Reinforced concrete RC) structure prefabricated steel modules (PSM) prefabricated concrete
modules (PCM) and prefabricated timber modules(PTM) that are most common solutions used by
contractors in the construction industry
4222 Requirement tree
These are groups of criteria which define a function to be evaluated A requirement usually
has several criteria Five requirements were selected based by literature review and the expertrsquos
opinions collected by survey among industrial players who were the participants of this questionnaire
Economic R1 time R2 environmental R3 safety R4 and social R5 requirements arranged in a way that
can examine the advantages adequately Time requirement were separated from economic one
because of importance due to high priority that have in the market to be chosen by the constructors
and clients In other words some clients and private builders choose the prefabrication methods such
as modular construction to save more time due to tight schedule that the project have Social and
safety requirements usually not being considered in sustainable decision-making processes but on this
study were included because the sustainability is not the only factor in project management
4223 Criteria
For each requirement a series of criteria are defined Criteria are the specific concepts that
the indicators contain the minimum unit to be quantified (wwwdecaupcedu) Each criterion was
chosen based on the importance among others efficiency on the project and availability of actual
amount and quantities in real cases over literature resources In other words the both advantages
and their functionality that modular construction have in comparison with traditional methods were
the main drivers to choose a criterion for each requirement as it mentioned earlier For economic
requirement cost of the project R1C1 was the only criteria that was considered which in the literatures
is expected to save 20 by choosing modular method in final cost (McKinsey amp Company 2019) while
experts in survey believe that the cost of transportation of prefabricated elements to the site can
compensate the difference with traditional method To examine these two opinions these criteria was
chosen In Time section the projectrsquos schedule R2C1 was only criteria to measure the important
advantage that the modular construction has Both literatures and expert agreed the time saving that
modular approach can bring to the project which is about 50
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES)
R1 - Economic
R1C1 - Project cost
R2 - Time
R2C1 - Project schedule
R3 - Environmental
R3C1 - Energy consumption
R3C2 - Waste generation
R3C3 - Material consumption
R3C4 - Noise Polution
R3C5 - Greenhouse gas emission
R3C6 - Recycle
R3C7 - Embodied energy
R4 - Saftey
R4C1 - Injury risks
R4C2 - Protection from natural cuases
R5 - Social
R5C1 - Job status
R5C2 - Quality
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
66 | P a g e
Seven criteria were chosen to cover the environmental requirements for this decision-making
process based on the available data in literatures However in this section not only advantages of
modular methods were considered but in some areas conventional reinforced concrete showed
better results and this fact can improve the liability and practicality of final decision For instance the
embodied energy of steel modular building is 30 more than the conventional during the construction
but the saving caused by re-useability of element in modular method can almost compensate the gap
between these two methods Energy consumption R3C1 which is the energy consumed during the
constructionfabrication amount of Waste generated R3C2 in all alternatives Material consumption
R3C3 in each method Noise pollution R3C4 Greenhouse gas emission R3C5 Recycle of elements R3C6
and Embodied energy for each method were chosen in this section
Safety issue as it has mentioned before was added to decide further than sustainability
concept boundaries which include two criteria Injury risk for workers R4C1 and Protection of project
from nature causes R4C2
Finally Social benefits which are not as main factors to be considered by construction players
to use the modular methods but are important enough to pay attention and were compared as well
by two criteria Job status R5C1 and Quality R5C2
4224 Indicators
The indicators for this study came directly from scientific articles which most of them were
published few months ago and it can be said that the data which were used for this study is updated
with the latest achievements in modular construction industry
To begin with for economic measurements two indicators for the project cost were selected
total project cost R1C1I1 and costs stability R1C1R2 Total project cost R1C1I1 for conventional RC
alternative means the final cost of construction including all the activities until the delivery of building
In modular alternatives PSM PCM and PTM includes the module fabrication in off-site plants
transportation installation on-site and final finishing of building after the assembly phase All
indicators are based on ldquoAustralian dollarsrdquo units (AUSD) because of the recourse quantities that was
used for this study which will be discussed more later Second indicator which is the costs stability
(R1C1R2) was chosen because of the common off-site production economic advantage that is
stabilizing the costs for the projectrsquos budget because of high quality of product more repetition of
elements and more accurate supervision on activities which leads to less reworks and less extra costs
etc
Total project schedule R2C1I1 is the first indicator for time requirement which include the
amount of time to fabricate transport and final assembly of the modules on-site in modular
alternatives and the final schedule of the conventional project during construction activities until the
delivery of the building which all are based on ldquodaysrdquo it was mentioned earlier that in off-site
production the project schedule can be estimated and controlled more adequately so that second
indicator which is time stability R2C1I2 was introduced to the study
Environmental requirement was studied in various features as it said before in 7 criteria which
shows the complexity of comparisons between alternatives First indicator is the Energy utilized during
construction R3C1I1 based on ldquoMJrdquo units Solid Waste R3C2I1 is the only indicator for Waste
generation criteria that focuses on the amount () of waste which was produced during
constructionfabrication activities in all four activities In material consumption criteria the total
amount of materials that was used for constructionfabrication of elements R3C3I1 is appointed as an
indicator to compare the benefits in each alternative based on ldquoKgrdquo Noise reduction in off-site
construction is another benefit that it has and to discuss this fact among the alternatives Average A-
weighted equivalent sound level of each construction equipment R3C4I1 based on ldquodBrdquo units was
focused on Greenhouse gas emission among alternatives was measured in CO2 that was produced
during constructionfabrication activities R3C5I1 based on ldquoKGrdquo units Two indicators were introduced
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
67 | P a g e
for recycle criteria between four alternatives recyclability or possibility of recycling of elements
R3C6I1 and Re-use of elements (Products) in projects R3C6I2 based on Percentages Embodied energy
was the last criteria which was focused on with two indicators Embodied energy used R3C7I1 in ldquoGjrdquo
units and Embodied energy saved by re-use of elements in percentages among alternatives
For safety measurements two indicators were selected for two criteria which are injury risk
level R4C1I1 for injury risk criteria and Protection level R4C2I1 for protection from nature causes both
in a qualitative unit
Job stability R5C1I1 for comparing the job status in terms of security of jobs among two
methods and new job creation R5C1I2 to analyse the possibility of providing new job positions which
is crucial in these era in construction industry were chosen in qualitative unit
The last criteria in social requirement which is quality of projects was presented with one
indicator of quality satisfaction of client R5C2I1 in qualitative unit to compare the clientrsquos satisfaction
level between alternatives Table 4 1 - Requirement tree with all indicators which considered for decision making process
Requirements Criteria Indicators
(R1) Economic (R1C1) Project Cost (R1C1I1) Total Project Cost
(R1C1I2) Cost Stability
(R2) Time (R2C1) Project schedule (R2C1I1) Total Project Schedule
(R2C1I2) Time Stability
(R3) Environmental
(R3C1) Energy Consumption (R3C1I1) Energy Utilized during construction
(R3C2) Waste Generation (R3C2I1) Solid Waste
(R3C3) Material Consumption (R3C3I1) Material Consumed in project
(R3C4) Noise Pollution (R3C4I1) Average A-weighted Equivalent sound Level of each instrument
(R3C5) Greenhouse Gas Emission (R3C5I1) Co2 in constructionfabrication
(R3C6) Recycle (R3C6I1) Recyclability of Elements
(R3C6I2) Re-use of elements
(R3C7) Embodied Energy (R3C7I1) Embodied Energy Used
(R3C7I2) Embodied Energy Saved
(R4) Safety (R4C1) Injury Risks (R4C1I1) Injury Risk Level
(R4C2) Protection from Nature Causes (R4C2I1) Protection Level
(R5) Social (R5C1) Job Status
(R5C1I1) Job Stability
(R5C1I2) New Job Creation
(R5C2) Quality (R5C2I1) Quality Satisfaction of Client
The input data for indicators are categorized in 4 types direct data calculated data estimated
data and qualitative data The reason for not having only direct data is the lack of enough literature
researches on this subject and in some cases the data were published two months before the date of
this study The variety of alternatives which is the first time that a study is going to analyse 3 modular
alternatives and a traditional method added difficulty to find useful data to do the decision making
reliable Moreover 5 articles were used for finding the correct data which each of them focused on
different alternatives The orientation of this study is the Cleaner Production journal by professor
Hammad that was published in 2019 which was mentioned earlier The reason of this orientation is
that most of the data came from this article and is more updated than the others
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
68 | P a g e
bull Direct Data
The direct data were the information that was related precisely to the alternatives without
any needs to change For instance the cost of the construction in Hammadrsquos article which can be used
without any changes The green parts on the Table 42 shows the direct data which are related to the
Hammadrsquos article Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed to be done on them
bull Calculated Data
In many indicators because of lack of existence in directly related data for alternatives a sort
of calculations were needed to change the data from other articles that related to alternatives that
are not focused in main case (Hammadrsquos article) to actual data based on the area of main article by
using accurate coefficients and ratios For instance in Hammadrsquos article CO2 was not estimated for
Prefabricated Steel Modules (PSM) alternative but Ayersquos CO2 data which is for total area of 3943m2
with 63 apartments each area of 628 m2 (close to 625 m2 area of Hammadrsquos granny flat) was used
by dividing on 63 apartments units so that results 54079 kg of CO2 for steel modular equivalent for
main case The yellow parts show the calculated data for indicators
3407000119896119892 1198881199002 divide 63 119906119899119894119905119904 (6251198982) = 54079119896119892 1198881199002 for steel modules in main case
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other studied
bull Estimated Data
Third type of input data were the necessary data which are not existed on any of literatures
of have to be estimated based on the qualitative information professional survey which have been
done before the decision making process (Chapter 3) and researcherrsquos opinions Fortunately in many
areas the data could be applied on other alternatives because of similarity of activities off-site and
onsite For instance for PCM alternative the noise and Injury risk level are approximately the same
the indicators of PSM case that have mentioned in Hammadrsquos article which are shown in green parts
in Table 42 because of similarity of off and on site activities during construction
The blue parts are the estimated data that were considered for PCM alternative based on
mentioned resources For instance the time indicator can be predicted 24 days few days more the
steel modules which is around 22 days because of the fact that concrete modules are heavier than
steel ones and has more complexity in structure for being produced that adds difficulties on
transportation process which leads to more delays on the schedule Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow)
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
69 | P a g e
bull Qualitative Data
This data was added because of two reasons first the lack of existence of direct data on
literatures and improve the literatures background on this subject and secondly to have more
influence from variety of benefits that modular construction has on the decision making process
Numbers of literatures insisted on advantages that can affect the decision making but did not
included on their data analyses at the end and this research decided to include these data and see
that how much functional can be in the decision making between alternatives in point of project
management view For instance cost stability which is better coordinated in off-site construction and
can be considered as an advantage to the decision making is not included in the literatures during
analysis and in this study is a vital factor for the economic criteria In order to add this indicator a
qualitative range was considered from 0 to 10 and four alternatives based on their functionality in cost
stability in project budget were compared to each other Traditional reinforced concrete building
which because of common reworks etc have less stability in final budget estimation On the other
side PSM and PTM which have the most repetition in manufacturing processes and ease of production
because of material type have the maximum cost stability of 9 out 10 among the others and PCM that
has less ease in production have less cost stability than other modular alternatives with 8 out of 10 Table 4 5 - Qualitative indicators
Final indicators
bull Prefabricated Steel Modules indicators (PSM)
As it mentioned before the direct data which are shown in green at table 46 do not need any
changes as they belong to the main case study while other indicators are still needed to be calculated
estimated and often considered qualitatively Aye case study have the closest data to the main case
study because of similarity of project type and dimensions so that the necessary indicators such as
material consumption waste generation percentage re-use amount and embodied energy indicators
can be calculated from this analytical study (For more information about indicators resources please
see Annex 1-A) Table 4 6 - First hand data over literature
A simple calculation is needed and that is dividing the CO2 emission Material
consumption and Embodied energy used amounts in Aye project on 63 apartment units with the
same area of 625 as main case in Hammads residential flat ldquoWaste amountrdquo ldquore-use of elementsrdquo
and ldquoembodied energy savedrdquo can be applied on the main case because of similarity of material
choices
IndicatorsAltertanives TRC PSM PCM PTM
Cost stability 6 9 8 9
Time stability 6 9 8 9
Recycleability of elements 3 8 7 9
Protection level 2 9 9 9
Job stability 5 8 8 8
New job creation 3 8 8 8
Quality satisfaction 5 9 8 9
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
70 | P a g e
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow)
bull Prefabricated Timber Modules indictors (PTM)
As it can be seen in table 48 there are no enough data over literature in many areas and due
to the necessities for this study a range of calculations and estimation have to be made based on the
similarity of projects among study cases and survey information Table 4 8 - First hand data over literature
Starting with Cost of the project which an ldquoestimationrdquo based on literature review information
and qualitative comparisons (John quale 2012) (Lu Aye2011) that is approximately 45000 AUD
because it proved that the cost of Timer modules is even cheaper than Steel Modules due to simplicity
of material choice and structure design The schedule of PTM building is shorter than the other
alternative because of numbers of reasons such as less weight of elements which can lead to faster
transportation loading and offload in assembly process on-site In addition the manufacturing lines
are simpler than other modular alternatives because of high repetitions and simplicity in design
For ldquocarbon emissionrdquo and ldquomaterial consumptionrdquo Aye project was used by diving on 63
apartment units which have the same area of 625 m2 as main case In terms of ldquowaste generationrdquo a
unique article was used (by Doyoon 2008) which did a LCA study on Timber modular building and the
amount of wastematerial consumed was about 9 The Noise level and Injury risk can be applied
from other modular alternative because of similarity of construction activities and equipment used
for fabrication Energy utilized during construction of Timer modules have the minimum amount in
comparison with other alternatives because of simplicity of material choice and design enhancement
so that was estimated 80MJ which is slightly less than steel modules with 86 MJ
Re-use of elements in timber modular elements was confirmed by survey among the
constructors over than 70 with a life span of 50 years Embodied Energy used was collected from
Aye case study dividing on 63 apartments units as same as other cases which equals to 65671 GJ
(Table 49) Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue)
bull Prefabricated Concrete Modules indicators (PCM)
The least focus on modular alternative was on Concrete Modules which is because of few uses
that this method has among the projects Balasbaneh study focused on a comparison between Steel
modules and Concrete modules in total project cost and LCA Table 4 10 - First hand data over literature
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury risk Energy utilized Re-use Embodied energy Emb saved
Aye 2500000 996 356 41373 691
Quale 13600
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 45000 20 39375 1580952 9 645 163 80 70 65671 691
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Balasbaneh 239380 8264
Units MLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
71 | P a g e
However the currency of this economic analysis is not as AUD (Australian Dollars) as the main
study Therefore to calculate the cost and CO2 footprint corresponding to main study case a ratio
was obtained between concrete modules amounts and steel modules in Balasbaneh study and then
multiplied to the steel modules quantities in Hammadrsquos main case and resulted project cost of
5188603 AUD and 46442 kg of CO2 emissions
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM alternatives
239380 divide 222580 = 1075478 119862119900119904119905 119903119886119905119894119900 (Balasbaneh study case)
482446 times 1075478 = 5188603 119860119880119863 Total project cost of PCM
8264 divide 9623 = 085877 1198621198742 119903119886119905119894119900
54079 times 085877 = 46442 119896119892 CO2 of PCM
The time indicator was estimated based on steel modules but with this difference that
concrete modules weight more than steel ones so that puts pressure on the transportation and
assembly phases and causes delays in the schedule as a result 24 days was predicted to finish the
project
There is no available information on the literature with specific quantitative details however
based on the qualitative structural information prefabricated concrete modules PCM because of their
similarity of material choice to conventional model have a massive material use in comparison with
Steel and Timber alternatives so that an estimated total material consumed of 20000kg assigned for
this indicator (Aye 2011) (Balasbaneh 2020)
Waste generation have a higher ratio in this alternative because of material choices which
generate more waste than other modular alternatives With this fact in mind the waste ratio
considered slightly more than steel kind with 10 (Aye 2011)
Noise level and Injury risk can be applied from other types because of similarity of equipment
and construction activities in all three modular alternatives (Hammad 2019)
Energy utilized during construction in PCM Alternative can be estimated more than steel ones
because of types of materials used in these modules and their high weight with value of 90MJ (Aye
2011)
The structural elements are ldquonotrdquo built in material which have a high recyclability potential so
that decreases the Re-use ratio to 20 approximately in comparison with other modular alternatives
(Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
72 | P a g e
Embodied energy used amount and its potential saving have the minimum value in a
qualitative comparison with other alternatives which respectively values of 800GJ and 60 were
estimated for them (Aye 2011) Table 4 11 - Final indicators for PCM
bull Traditional Reinforced Concrete (TRC) final indicators
The highest focus over the literature is to make a comparison between one of the modular
options and a traditional method which results more availability for direct data for Traditional method
The main case study is not an exception with almost half of the value are available directly such as
Project cost Time Noise level Injury risk and Energy utilized during construction which are shown in
green at table 412 (Hammad 2019) Table 4 12 - TRC first-hand data over literatures
Nevertheless still there are values that must be calculated over literature Green gas emission
indicator and Embodied Energy used were calculated form Ayersquos case study by dividing the values on
63 apartment units which results 3620635kg Co2 emission and 6033 GJ of 625 m2 area as same as
main case study (Aye 2011) (Hammad 2019)
Material consumption have the same methodology as carbon footprint with final value of
626825kg which is massively higher from modular alternatives (Aye 2011) (Hammad 2019)
Waste generation was calculated qualitatively from a literature resource called ldquoModular
Construction for Multifamily Affordable Housingrdquo by WSP which acclaims that the conventional site-
built method produces around 25 times more construction waste (WSP 2018) Thus TRC waste
generation is more than 25 times of modular ones with the value of 15
Two values of Re-use and Embodied energy saved by Re-use of elements were obtained from
Ayersquos case study respectively 22 and 322 (Aye 2011) Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow)
In general the table 414 shows the References and final indicator values that were used for decision
making process (Direct data are shown in Green Calculated data in yellow and estimated data in
blue)
Table 4 14 - Final Quantitative indicators used for decision making process
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 812298 6598 71 217 198
Akbarnejad 120000 67 84672
Aye 2281000 3949 22 38008 322
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
PSM 482446 2131 54079 138254 5 645 163 8593 50 9012 813
PTM 45000 20 39375 1580952 9 645 163 80 70 65671 691
PCM 5188603 24 46442 20000 10 645 163 90 20 800 60
TRC 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrence Ham Aye Balas Hammad Balas Aye Aye Doyoon WSP Aye Hammad Hammad Hammad Aye Aye Aye
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
73 | P a g e
Weights
The Weights (Pesos in MIVES) which are one of the most important factors in decision making
process have be assigned on the data in a way that the priority of each section in terms of efficiency
and importance can decide which value will have among the others AHP method was used to assign
weights on the data In AHP you get the weights through the subjective importance of each element
with respect to the others (Alejandro Josa 2012)
bull Weights of requirments
The importance of requirmenets was assumed based on proffessional survey among
constructors architects sales agents and clients in order to know the demands of market and make
the decision rely on what market expects from a innovative method According to the survey time
reduction is the first priority for choosing the modular methods by constructors and future clients so
than acheived 30 of weight Economic issues came after the time factor because of unconsistency
between responds about cost saving on the budget or offseting the expenses gap by tarnsportation
extra costs on the project Economic requirement has 27 of weight In some regions the priority of
choosing an innovative method are environmental emissions waste generation and recycleability of
products Therefore environmental requirement came after the economic one with 25 of weight
As it mentioned before Social and safety advantages are included in this decision making
process with respectly weights of 13 and 5 because of their less priorities among clients and market
players Table 4 15 - Requirement weights
Requirement Economic Time Environmental Safety Social
Weights 27 30 25 13 5
bull Weights of criteria
In cost and time of project which are single criteria have 100 of weights However for
instance in environmental and AHP method must be used to assign the weights based on the
importance in an environmental consideration The amount of emission that construction activities
can produce and the amount of negative effect on the global environment have been considered for
AHP method in weight assignment process Energy consumption and material consumption have the
priority to consider in LFA analysis because the consumption of primary resources have to be
minimized in a project at the first step and then the emission have to be reduced by changing the
processes etc Finally the ability to re-use and recycle and elements must be improved (Mohammad
Kamali 2017) (John Quale 2012) (Marta Gangolells 2014) Therefore Energy Consumption and
Material consumption have the most weight of 17 Embodied energy with 16 and waste generation
Greenhouse Gas emission and Recycle achieved 15 of weight At last noise Pollution took the least
priority of weights with 5 Table 4 16 - Weights of criteria
bull Weights of Indicators
Both of Economic and Time indicators divided to two sub-categories project cost and time and
their stability ratios with 80 and 20 weights by AHP method
Criteria that are single indicator obviously have 100 of weights However there are two
indicators in recycle criteria Recyclability and Re-use of elements with 40 and 60 weight
respectively Moreover Embodied Energy have is divided to Embodied energy used which is more
CriteriaEnergy
consumption
Waste
generation
Material
Consumption
Noise
pollution
Greenhouse
gas emissionRecycle
Embodied
energy
Weights 17 15 17 5 15 15 16
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
74 | P a g e
important than the other that is saving in embodied energy by re-use because as it mentioned before
in the first place the use have to be minimized and then actions such as re-use of elements have to be
done 70 of weight for Embodied energy use and 30 for Saved Embodied energy are assigned Job
stability and New job creation with weights of 50 each are the Job status indicators (Figure 411)
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software
Value function play an important role on deciding which comparative final value can each
indicator have among the other indicators for each alternative To evaluate the sustainability index
(Is) of each alternative solution value functions assigned and were used (Alarcon et al 2011) The
generic form of a value function is represented by Table 417 which allows to assess the sustainability
(satisfaction) associated with each indicator by transforming the physical units to a dimensionless
value between 00 and 10
Equation 4 1 - Functionality of value function elements
In Eq (41) B is the value of indicator(Iind) for Xmin Xmin is the minimum abscissa value in the
indicator interval assessed X is the abscissa value for the indicator assessed Pi is a shape factor which
defines whether the curve is concave (Pi lt 1) convex (Pi gt 1) linear (Pi = 1) or S-shaped (Pi gt 1) (see
figure 412) Ci approximates the abscissa at the inflexion point Ki tends towards (Iind) at the inflexion
point B the factor that prevents the function from exceeding the range (0 1) is obtained by Eq (42)
Xmax being the abscissa value of the indicator that gives a response value of 1 for increasing value
functions
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
75 | P a g e
Equation 4 2 - B value equation
Figure 4 12 - Possible forms of the value function
Due to the lack of existence of resources for assigning the specific value functions for modular
alternatives some hypotheses that can increase the feasibility and sustainability of project were
considered for the shape P K and C values to select the best form of abacus
In the other side maximum and minimum satisfaction points were selected on the
expectations of a project management view For instance in total project cost indicator case
minimum satisfaction point is 82000 AUD that is slightly more than the traditional reinforced concrete
alternative project cost (812298 AUD) because of the fact that those alternatives should be
considered as a reasonable options which can make saving in final budget Moreover the same rule
can be applied for maximum satisfaction point which is close to the Timber Modular alternative (45000
AUD) to minimize the final budget as much as possible The shape of the abacus was selected as
Convex shape (Convexa in MIVES) because even the least economic saving that an alternative can
achieve have a positive effect on the satisfaction of project and can be given any positive points in a
scale of ldquo0 to 10rdquo But the more the curve closes to the traditional alternative budget the les
satisfaction it can receive (Figure 413)
Figure 4 13 - Value function for total project cost in MIVES
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
76 | P a g e
The following Table 417 includes the value functions which were used for the rest of the
indicators Table 4 17 - Value function for indicators in MIVES
Data analysis
Indicators Values
Indicator data were translated to general normalized values shown in Table 418 amp 419 based
on the given value functions that earlier assigned This step is crucial for next analyses which will be
done to result the criteria and requirement values which lead to sustainability Indexes that can take
the multi-criteria decision As it can be seen these values have the same range of 0 to 1 so that can be
compared in with a common unit Comparisons are obvious in this level because of single value
orientation of each indicator however on following analysis there will be multi-criteria comparisons
which can achieve useful data for future decision-making process Table 4 18 - Indicators normalized values
Table 4 19 ndash Indicator normalized values
Indicators Lower limit Upper limit Max satisfaction Min satisfaction P K C Shape
Total Project Cost 30000 90000 43000 82000 05 05 79900 Concave
Cost stability 0 10 10 5 05 05 55 Concave
Total Project Time 20 75 20 68 05 05 632 Concave
Time stability 0 10 10 5 05 05 55 Concave
Energy Utilized 75 220 80 205 05 05 1925 Concave
Solid Waste 0 100 0 18 08 05 162 Concave
Material Consum 10000 70000 12000 63000 05 05 57900 Concave
Noise Level 58 78 62 72 05 05 71 Concave
CO2 32000 60000 32000 55000 05 05 52700 Concave
Recyclability 0 10 10 0 05 05 1 Concave
Re-use 0 100 60 0 05 05 20 Concave
Embodied energy 600 950 600 915 05 05 8835 Concave
Embodied saved 0 100 90 30 05 05 36 Concave
Injury risk 0 4 155 22 05 05 2135 Concave
Protection level 0 10 10 0 1 001 1 Lineal
Job stability 0 10 9 4 1 001 45 Lineal
New job creation 0 10 10 0 05 05 5 Concave
Quality Satisfaction 0 10 10 0 1 001 5 Lineal
R1C1I1 R1C1I2 R2C1I1 R2C1I2 R3C1I1 R3C2I1 R3C3I1 R3C4I1 R3C5I1
TRC 016 051 024 051 027 029 01 034 092
PSM 094 092 098 092 098 082 099 088 023
PCM 09 081 097 081 097 059 093 088 065
PTM 098 092 1 092 1 064 097 088 085
R3C6I1 R3C6I2 R3C7I1 R3C7I2 R4C1I1 R4C2I1 R5C1I1 R5C1I2 R5C2I1
TRC 073 026 1 024 024 021 02 063 05
PSM 095 094 023 095 094 09 08 092 09
PCM 092 068 064 077 094 09 08 092 08
PTM 098 084 092 085 094 09 08 092 09
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
77 | P a g e
Criteria Values
MIVES analysed each criterion by single or multi-indicator normalized values and resulted
values with a same range of 0 to 1 for following comparisons Table 4 20 - Criteria normalized values
Table 4 21 - Criteria normalized values
To begin with Project Cost (R1C1) criteria values shows that Almost three modular
alternatives performed 3 times more than the traditional method positively caused by hugely less total
project cost (R1C1I1) and great cost stability (R1C1I2) in project final budget The minimum value
belongs to PTM with 097 and slightly more than PSM and PCM is the next alternative with a value of
088 and at last TRC with 023 (Figure 414)
Figure 4 14 - Criteria normalized values
The comparison between modular alternatives in terms of which one can save time on the
schedule is close and it can be said that all three can make the project executed more than 3 times
shorter than traditional approach Timber steel and concrete options with respectively 098 097 and
094 values were compared to the conventional concrete method with 029 value (Figure 415)
R1C1 R2C1 R3C1 R3C2 R3C3 R3C4
TRC 023 029 028 029 009 032
PSM 094 097 099 083 099 088
PCM 088 094 096 059 094 088
PTM 097 098 101 064 096 088
R3C5 R3C6 R3C7 R4C1 R4C2 R5C1 R5C2
TRC 091 045 083 024 021 040 052
PSM 024 096 048 095 090 088 092
PCM 064 077 072 095 090 088 080
PTM 085 091 096 095 090 088 092
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
78 | P a g e
Figure 4 15 - Project Schedule
ldquoEnergy saving potentialrdquo in modular methods are close to the maximum satisfaction point
with timber solution and steel modules while concrete option is on the chase with 096 While
Traditional alternative only have 28 of satisfaction level
ldquoWaste generationrdquo among the alternatives have a different attitude while traditional method
with value of 029 has the most ratio of material waste production modular alternatives are
performing better where steel option have the most reduction with value of 083 and follow to that
timber and concrete options respectively 064 and 054 values PCM alternative as it said before
because of similarity of material choice to TRC have the minimum performance among the other
three (Figure 416)
Figure 4 16 - Waste generation ratios
ldquoMaterial consumptionrdquo criteria are dominated by modular methods which have a high
satisfaction with over than 09 normalized values while TRC performance can be concerning for the
primary resources with 01 normalized value
Previously on this report the fact was mentioned that off-site construction can benefit the
environment with noise reduction during construction activities based on literatures and this study
confirms this advantage by 088 values of all three modular alternatives and 032 value of traditional
RC which is less than half of modular options
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
79 | P a g e
A highlight of this study is about the comparison of CO2 Emissions of alternatives during the
constructionfabrication activities which traditional method have the minimum contamination with a
value of 091 and follow to that Timber option with 085 which is close to the TRC method Later to
that Concrete modules have a value of 064 and the minimum satisfaction belongs to the steel
modules with 024 normalized value This result bring uncertainty to the fact that modular
construction can reduce the Greenhouse gas emission to 30 over the literature review
Figure 4 17 - CO2 Emission normalized values
This study shows that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options with a value of 096 because of the material choice
repetition in element manufacturing and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution have 091 value that can confirm the concept of
recyclability for wooden modules which was mentioned by participants in professional survey as well
Figure 4 18 - Recyclability and re-use potential of alternatives
There is a discussion about the amount of embodied energy used during the lifetime of each
alternative and the potential of future saving by re-use of elements in projects which effect the total
embodied energy consumption in construction
As the Figure 419 explains traditional method has the maximum satisfaction level in terms
of consumption while steel modules have the least satisfaction of life cycle embodied energy used of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
80 | P a g e
023 PTM have a better value of 091 which shows that Timber solution can be reliable among the
others
However this study resulted that the most re-use value belongs to steel option with 095
value that and other two timber and concrete modules respectively with 085 and 077 can
compensate the gap with traditional method that has only 024 Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction total value of 096 Later
traditional reinforced concrete method with 088 still proves its abilities over other two modular
alternatives
Figure 4 19 - Embodied energy consumption and saving potential by reuse
In terms of safety modular alternatives because of their off-site nature can provide a high
satisfaction level with values of 095 in injury risks for workers and 090 protection from nature causes
which confirms the theory of safety advantage of modular construction over traditional methods from
literature studies (Figure 420)
Figure 4 20 - Safety advantage of modular construction over traditional method
Social benefits which were mentioned in literature review section also had been examined in MIVES
system and the job stability and job creation in modular construction can benefits the construction
society in significant way among the regions that have employability ratio problem
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
81 | P a g e
Figure 4 21 - Social criteria
Requirement Values
After analysis on criteria functions general values of each requirement were related to
alternatives achieved which can examinate all four construction methods to know which option is
more suitable in terms of Economic time environmental safety and social issues
The Table 422 below demonstrates the Requirements normalized values for each alternative Table 4 22 - Requirement normalized values for four indicators
bull Economic and Time requirements
As the graph illustrates Modular methods have a significant performance in economic and
time terms with the maximum values of 097 and 094 in Time and 098 and o97 in Economic
requirement for Timber and then Steel modules-based methods respectively Traditional reinforced
concrete option showed a poor functionality in cost and time of project with minimum values of o29
and 023 in order (Figure 422)
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values analysed by MIVES
Requirements Economic Time Environmental Safety Social
TRC 023 029 045 022 046
PSM 094 097 075 093 088
PCM 088 094 078 093 084
PTM 097 098 088 093 088
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
82 | P a g e
bull Environmental requirement
Generally all three modular approaches have beaten the traditional method with almost
double of normalized values in comparison
Despite the poor performance of steel modules in Greenhouse gas emissions and Embodied
Energy used in construction in total numbers proved that can provide the environmental demands
better than traditional option with a value of 075 which is third modular alternative in overall
Prefabricated Timber modules obtained the maximum value of 088 which claims not only
most economic option but environmentally friendly among other relatives and following to that
Concrete modules with value of 078 shows its liability to be chosen in case of need while the
traditional concrete method which includes most of the used materials n PCM but in a on-site plant
only can achieve a satisfaction value of 045 among the others (Figure 423)
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind
bull Safety and social requirements
The dominance of Modular construction in safety and social requirements over conventional
option can be seen in Figure 424 which can raise the possibility of modular methods to be the best
decision over the traditional option to construct this residential project As it was mentioned before
these two criteria must be considered in any decision-making process because of their high
importance in construction industry
Figure 4 24 - Modular dominance in safety and social requirements over conventional option
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
83 | P a g e
Sustainability Values (Final decision)
Finally the sustainability Indexes can be obtained to claim which alternative will be decided
as the most sustainable option for the main studyrsquos project to be build The needs of market such as
short project schedule cheaper budget reduction in environment emissions and ability to
recyclereuse safety measures and social benefits put effects on this decision as previously
mentioned
Table 423 explains that Prefabricated Timber Modules (PTM) is most sustainable alternative
among the other with a perfect normalized value of 094This could be because of its shorter schedule
of construction lowest total budget and excellency in environmental performance among the other
alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative Table 4 23 - SI (Sustainability Indexes related to four alternatives)
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This fact explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives
TRC PSM PCM PTM
SI 032 090 088 094
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
84 | P a g e
5 Conclusions Decision making process
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria etc However to find out how much practical these benefits are in the market several trade-
offs must be done by professional tools such as project management software programs which can
take decisions based on the input data that receive MIVES software was used in this study to
examinate these benefits The resources for this type of studies are limited due to the lack of focus or
newfound nature of this subject and only five of them were selected because of their variety of their
criterion studies reliability and accuracy of data Requirements criteria indicators and weights that
were used in MIVES had been selected based on demands of market and professional opinions
received from the survey and availability of data over references After assigning the value functions
which are related to satisfaction level on each criterion (For instance cost reduction time saving and
minimization of emissions) normalized values were achieved that can be compared between
alternatives with range of 0 to 1
Conclusions and discussion
ECONOMIC ndash TIME discussion
bull Decision-making result
Generally all three modular alternatives have beaten the traditional method with almost
double of normalized values Modular methods had a significant performance in economic and time
terms with the maximum values in Time and Economic requirements for Timber and then Steel
modules Traditional reinforced concrete option showed a poor functionality in cost and time of
project with minimum values
Literature reviews information
These Results confirm the 50 of time saving in projectrsquos schedule (McKinsey amp Company
report 2019) and 20 of cost reduction on the budget which was mentioned also in numbers of
literatures
Professional survey confirmation
In addition the claims from professional participants in survey about the 50 cost reduction
due to the added value of every hour of work in comparison with traditional stick and build on-site
method can be approved even far more those expectations
ENVIRONMENTAL discussion
bull Recyclability and re-use potential
This study showed that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options because of the material choice repetition of
elements in manufacturing line and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution can confirm the concept of recyclability for wooden
modules which was mentioned by participants in professional survey as well
bull Embodied energy used and saving by re-use
There is a discussion over the literature and survey participants about the amount of
embodied energy used during the lifetime of each alternative and the potential of future saving by re-
use of elements in projects which effect the total embodied energy consumption in construction
where one of the companies acclaims that ldquoour homes are not positive in energy consumption
aspectrdquo Traditional method has the maximum satisfaction level in terms of consumption while steel
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
85 | P a g e
modules have the least satisfaction of life cycle embodied energy used PTM have a better value of
091 which shows that Timber solution can be reliable among the others However this study resulted
that the most re-use value belongs to steel option and other two timber and concrete modules
respectively can compensate the gap with traditional method Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction Later traditional reinforced
concrete method still proves its abilities over other two modular alternatives
bull Greenhouse gas emission
Despite the poor performance of steel modules (PSM) in Greenhouse gas emissions that bring
uncertainty to the fact that modular construction can reduce the Greenhouse gas emission to 30
over the literature review and Embodied Energy used in construction proved that can provide the
environmental demands better than traditional option which is third modular alternative in overall
comparison
bull Most environmentally friendly alternative
Prefabricated Timber modules obtained the maximum value which achieves not only most
economic option but environmentally friendly among other relatives Following to that Concrete
modules shows its liability to be chosen in case of need while the traditional concrete method which
includes most of the used materials of PCM but in an on-site plant only can achieve the minimum
value
Comparison with literature review information and survey outputs
This comparison explains the truth about the concept of being environmentally friendly about
modular construction that have been mentioned in various scientific articles (McKinsey amp Company
report 2019) (M Kamali 2016) and the survey results which confirmed the concept in real cases at
the market over years of experience
SAFETY AND SOCIAL dominance by modular methods
The dominance of Modular construction in safety and social requirements over conventional
option was resulted which can raise the possibility of modular methods to be the best decision over
the traditional option to construct this residential project As it was mentioned before these two
criteria must be considered in any decision-making process because of their high importance in
construction industry Social benefits which were mentioned in literature review section also had been
examined in MIVES system and the job stability and job creation in modular construction can benefits
the construction society in significant way among the regions that have employability ratio problem
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES
Prefabricated Timber Modules (PTM) is most sustainable alternative among the other with a
perfect normalized value of 094This could be because of its shorter schedule of construction lowest
total budget and excellency in environmental performance among the other alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This result explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
86 | P a g e
Effective external factors on decision
The decision was made for the best alternative in terms of sustainability for a specific
residential case located in Sydney Australia among three modular options and one traditional
method However there are factors which can affect the final decision obviously Such as the location
of the project which the availability of primary resources can change the or alternatives or number of
indicators The local market and their demands for specific products can be crucial for choosing the
best method which affect the priorities of weights Regulation of every regions as it was mentioned
before can change the project requirements and indicators
The type of the project was a residential building that has its own characteristics but for
instance a school or hospital project would demand a higher functionality and lifetime because of their
distinctive operation kind and evidentially can be considerable in decision-making process to the end
step Special project due to their unique requirements often do not consider all criterions For
instance emergency health stations demanded during the Virus pandemic period have their own
material choose design enhancement and priorities on requirements
Future studies
Due to novelty of this subject there are numbers of studies still remained without coverage
which might be studied in future
Decision making study on two real projects with the input data of professional
modular and traditional constructors
Due to the lack of information over literature there were so many elements that have been
estimated by hypothesis and survey information therefore it is crucial to find these data in order to
do a precise study with real numbers These data can be obtained by requests to industry players to
have access of real project details including budget schedule material consumptions etc By this
action the liability of the study can be improved and accurate results can be achieved Thus a
decision-making process can be done to find out which alternative can be more sustainable
Technological studies about the production line of a modular off-site plant by factory
and on-site visits
There are still uncertainties about the status of use of automation productivity rate etc which
have to be analysed closely Modular construction was suggested as an example of industrialization in
construction industry to improve the productivity rate but corresponding to past survey the majority
of constructors are not benefiting from automation in their production lines and assembly processes
A study is needed on different phases of a project that have to be monitored and analysed scientifically
in order to find challenges errors and possible solutions to make this method even more sustainable
A survey about challenges in modular construction and its possible solutions to find
adequate solutions
Challenges have to focused more on this method because its players are still suffering from
the incompatibility of construction industry and the projectrsquos old conditions with innovative solutions
Series of interviews with experts factory visits etc have to be done to hear the voices of them and
then researchers to find solutions to update the industry and help them for growth
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
87 | P a g e
Recommendations
Cooperation between industrial players and scientific researchers in offsite
construction
Numbers of contrasts where found in the data and results among literatures professional
participants of survey and the decision-making study which shows a poor status of cooperation
between scientific researchers and professional players in the construction industry It is obvious that
the real data from the constructors designers etc in real projects are more reliable than scientific
estimation which in this case were based on BIM models and approximate calculations without any
interruption effects of common challenges in industry There were few participants who did not want
to share their project details in public or even education purposes or in a case one of the most
innovative players in modular industry responded their lack of available time to respond the survey
by direct email These attitudes can increase the gap between two vital elements for improvement
which are science and industry in construction society and to reduce it cooperation must be increased
specially in off-site society
Education about industrialization in construction and its alternatives
The idea of lack of education among engineers and architects who enter the professional
society about off-site construction methods was proved by the collected information from survey
participants which can cause problems in the projectrsquos design coordination and execution processes
These series of errors must be resolved by updating the education resources about innovative
methods such as off-site construction industrialization in construction concept rather than traditional
on-site methods that still occupy most of the educational courses these actions can improve the
common challenges in construction industry such as productivity problem and sustainability rate by
encouraging the researchers even far beyond the boundaries of investigations and make the way
possible to find more innovative solutions such as robotic fabrication 3D concrete printing etc
Establishing international and regional adequate codes
Use of automation is suggested by the researchers and industry players to raise the
productivity and sustainability in construction as the other industries which resulted positively
However constructors and manufacturers are suffering from a lack of exitance of international united
codding for their production line and boundaries and uncertainties by local regulations
To resolve these issues participants addressed an international code similar to what on-site
traditional methods have which the responsibility of creation of these codes are on the shoulders of
researchers and professional experts with a mutual partnership that is only possible with cooperation
of industry with science as it mentioned before
Synchronizing the contract conditions with modular construction conditions
There are numbers of problems in terms of contract conditions such as misunderstanding by
final client who is the end home buyer who ldquobelieves the factory to be the builder and the actual
independent builder to be a sales agent for the factoryrdquo one of the participants mentioned A
recommended solution for this problem is to define the relationships between the participants of
projects their responsibilities For instance requiring the builders customer to sign a disclosure
acknowledgement from that describes the relationship in detail In addition there is a lack of quality
partners on site The problem starts when on-site participants realize the advantages of modular
construction they tend to increase their prices for services which can increase the final prices of
project Another challenge which modular projects can face is the lack of delivery of project on agreed
time with an unacceptable quality of on-site execution The professionals answered that the
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
88 | P a g e
responsibility of ensuring that the work is done properly belongs to the builder which any ldquodelays in
this can result in postponed transport of product and interest through demurrage chargesrdquo
These problems must be solved by defining unique types of contracts that are adapted with
the off-stie construction nature and be obeyed by all the participants globally
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc
The only value that the market considers choosing modular method over traditional
construction is to be cheaper while majority of people the media and even professional engineers do
not understand the capabilities of modular construction Many people continue to confuse this form
of construction with HUD on frame products Another wrong perception that the publicmarket
believes is that the prefabrication methods limits the design options while some players believe that
the reverse is the case Therefore by using one of the main advantages of modular construction which
is shorter schedule the market can be dominated by modular projects and the more cases they
deliver the more recognised this method would be among the public and at the end the superior
nature of modular approach can be proved Another solution is a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Many of these wrong perception and misunderstandings can be
clarified by well-organized advertisements about several advantages that modular construction have
in comparison with conventional methods
Changes in financial strategies and adapting them with off-site construction nature
Financial assists which are crucial for kind of projects that are dependent to these aids are
not harmonized with modular project processes where there are argues that until the first deliveries
of elements to the site location and their assembly these aids will not be reachable This issue creates
pressure on cash flow of project where bank finance is involved Changes in contract conditions and
education for financial supporters are recommended solutions to improve the partnerships in
projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
89 | P a g e
6 References 1) Balasbaneh AT Ramli MZ A comparative life cycle assessment (LCA) of concrete and
steel-prefabricated prefinished volumetric construction structures in Malaysia Environ Sci
Pollute Res (2020) httpsdoiorg101007s11356-020-10141-3
2) Doran D and Giannakis M (2011) An examination of a modular supply chain a
construction sector perspective Supply Chain Management Vol 16 No 4 pp 260-
270 httpsdoiorg10110813598541111139071
3) Lawson RM Ogden RG Bergin R 2012 Application of modular construction in high-rise
buildings Journal of Architectural Engineering httpsdoi101061(ASCE)AE1943-
55680000057
4) Diez R et al (2007) lsquoAUTMOD3 The Integration of Design and Planning Tools for Automatic
Modular Constructionrsquo International Journal of Advanced Robotic Systems httpsdoi
1057725671
5) Lee J Park M Lee H ampamp Hyun H (2019) Classification of Modular Building
Construction Projects Based on Schedule-Driven Approach Journal of Construction
Engineering and Management 145(5) 04019031 httpsdoi101061(asce)co1943-
78620001656
6) Barbosa F Woetzel J Mischke J Ribeirinho M Sridhar M Parsons M Brown S
(2018 July 09) Reinventing construction through a productivity revolution Retrieved
September 28 2020 from httpswwwmckinseycomindustriescapital-projects-and-
infrastructureour-insightsreinventing-construction-through-a-productivity-revolution
7) Quale J Eckelman MJ Williams KW Sloditskie G and Zimmerman JB (2012)
Construction Matters Comparing Environmental Impacts of Building Modular and
Conventional Homes in the United States Journal of Industrial Ecology 16 243-253
httpsdoi101111j1530-9290201100424x
8) Horwitz-Bennett Barbara (2020) Rising to the challenge sl Modular Building Institute
(MBI)
9) Lu N amp Korman TM (2010) Implementation of Building Information Modeling (BIM) in
Modular Construction Benefits and Challenges
10) Institute Modular Building 2019 Permanent Modular Construction Canada Modular
Building Institute
11) Josa A (2012) Introduccioacuten a MIVES y el anaacutelisis multicriterio Jornada sobre la Importancia
de un meacutetodo para la toma de decisiones modelo MIVES para una ingenieriacutea sostenible
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
90 | P a g e
12) Aye L Ngo T Crawford R H Gammampila R amp Mendis P (2012) Life cycle greenhouse
gas emissions and energy analysis of prefabricated reusable building modules Energy and
buildings 47 159-168
13) Kamali M amp Hewage K (2016) Life cycle performance of modular buildings A critical
review Renewable and sustainable energy reviews 62 1171-1183
14) Lawson M Ogden R Goodier C (2014) Design in Modular Construction London CRC
Press httpsdoiorg101201b16607
15) Generalova E M Generalov V P amp Kuznetsova A A (2016) Modular buildings in modern
construction Procedia engineering 153 167-172
16) Thompson J (2019) Modular Construction A Solution to Affordable Housing Challenges
Cornell Real Estate Review 17(1) 21
17) Modular construction for multifamily affordable housing (2018) WSP
httpscdnymawscomwwwnibsorgresourceresmgrosccepa-modular-construction-
forpdf
18) Hammad A W A amp Akbarnezhad A (2017) Modular vs conventional construction a
multi-criteria framework approach In ISARC Proceedings of the International Symposium on
Automation and Robotics in Construction (Vol 34) IAARC Publications
19) Ferdous W Bai Y Ngo T D Manalo A amp Mendis P (2019) New advancements
challenges and opportunities of multi-storey modular buildingsndashA state-of-the-art review
Engineering Structures 183 883-893
20) Bertram N Fuchs S Mischke J Palter R Strube G amp Woetzel J (2019) Modular
construction From projects to products McKinsey amp Company Capital Projects amp
Infrastructure 1-34
21) Hsu P Y Aurisicchio M amp Angeloudis P (2020) Optimal logistics planning for modular
construction using multi-stage stochastic programming Transportation Research Procedia
46 245-252
22) Rausch C Nahangi M Perreault M Haas C T amp West J (2017) Optimum assembly
planning for modular construction components Journal of computing in civil engineering
31(1) 04016039
23) Connor G Jones C E amp Finney S J (2014) Easing future low voltage congestion with an
AC chopper voltage regulator httpsdoi 101061(ASCE)CO1943-78620001001
24) Ahn Y H amp Kim K T (2014) Sustainability in modular design and construction a case
study of lsquoThe Stackrsquo International Journal of Sustainable Building Technology and Urban
Development 5(4) 250-259
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
91 | P a g e
25) Gunawardena D Mendis P Ngo D Aye L amp Alfano J (2014) Sustainable prefabricated
modular buildings httpsdoi 10131402148473920
26) Olearczyk J Al-Hussein M Bouferguene A amp Telyas A (2009) Virtual construction
automation for modular assembly operations In Construction Research Congress 2009
Building a Sustainable Future (pp 406-415)
27) Woźniak-Szpakiewicz E (2016) EU migrant crisis and increasing demand for modular
construction modular social housing complex for refugees in Munich In Back to the Sense
of the City International Monograph Book (pp 921-931) Centre de Poliacutetica de Sogravel i
Valoracions
28) Wunderlich-Malec 2019 The Modular Solution to Reduce Total Construction Costs
httpswwwslidesharenetJoelGil2wuderlich-malec-engineering-modular-construction
29) HAMMAD AWA AKBARNEZHAD A WU P WANG X and HADDAD A 2019 Building
information modelling-based framework to contrast conventional and modular construction
methods through selected sustainability factors Journal of Cleaner Production [en liacutenea] vol
228 pp 1264ndash1281 ISSN 0959-6526 DOI httpsdoiorg101016jjclepro201904150
Disponible en httpwwwsciencedirectcomsciencearticlepiiS0959652619312296
30) HONG J SHEN GQ LI Z ZHANG B and ZHANG W 2018 Barriers to promoting
prefabricated construction in China A costndashbenefit analysis Journal of Cleaner Production
[en liacutenea] vol 172 pp 649ndash660 ISSN 0959-6526 DOI
httpsdoiorg101016jjclepro201710171 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS0959652617324782
31) LOPEZ D and FROESE TM 2016 Analysis of Costs and Benefits of Panelized and Modular
Prefabricated Homes Procedia Engineering [en liacutenea] vol 145 pp 1291ndash1297 ISSN 1877-
7058 DOI httpsdoiorg101016jproeng201604166 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS1877705816301734
32) NEELAMKAVIL J 2009 Automation in the Prefab and Modular Construction Industry [en
liacutenea] Sl sn DOI 1022260ISARC20090018 Disponible en
httpwwwiaarcorgpublicationsproceedings_of_the_26th_isarcautomation_in_the_pref
ab_and_modular_construction_industryhtml
33) SANTIAGO M ALBERTO J MARIA NJ and PATRICIA G 2008 Building industrialization
robotized assembly of modular products En M ONORI (ed) Assembly Automation [en
liacutenea] vol 28 no 2 pp 134ndash142 ISSN 0144-5154 DOI 10110801445150810863716
Disponible en httpsdoiorg10110801445150810863716
34) McGeorge D amp Zou P X (2012) Construction management new directions John Wiley amp
Sons
35) Fieldwire (2018) Why the Construction Industry Is Stuck in the Past
httpswwwfieldwirecomblogis-construction-stuck-in-the-1960s
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
92 | P a g e
36) Construction industry - Office for National Statistics (2019) ONS
httpswwwonsgovukbusinessindustryandtradeconstructionindustry
37) Timmer M P O Mahony M amp Van Ark B (2007) EU KLEMS growth and productivity
accounts an overview International Productivity Monitor 14 71
38) Smith A (2011 September 22) Agile and Lean for Construction SlideshareNet
httpswwwslidesharenetadrianlsmithagile-and-lean-for-construction-9384237
39) The massive opportunity of digitization in Engineering amp Construction (2019)
JourneyappsCom httpsjourneyappscomblogmassive-opportunity-digitization-
engineering
40) Tapscott D amp Tapscott A (2018) Blockchain Revolution How the Technology Behind
Bitcoin and Other Cryptocurrencies Is Changing the World (Reprint ed) Portfolio
41) Can Blockchain Fix the Construction Industryrsquos Productivity Problem (2018) Enstoa
httpsenstoacomblogcan-blockchain-fix-construction-industrys-productivity-problem
42) Itanola M (2019 June 5) Hey Quantity Surveyor is BIM going to take your job Blaze
Threads httpswwwblazethreadcomhey-quantity-surveyor
43) BIM Community (2017) Remodeling Construction Industry with Digitization BIM and
Reality Capture httpswwwbimcommunitycomnewsload563remodeling-
construction-industry-with-digitization-bim-and-reality-capture
44) Kolarevic B (2003) Digital production Architecture in the digital age design and
manufacturing 38-63
45) Labonnote N Roslashnnquist A Manum B amp Ruumlther P (2016) Additive construction State-
of-the-art challenges and opportunities Automation in construction 72 347-366
46) Kapoutsis A C Chatzichristofis S A Doitsidis L de Sousa J B Pinto J Braga J amp
Kosmatopoulos E B (2016) Real-time adaptive multi-robot exploration with application to
underwater map construction Autonomous robots 40(6) 987-1015
47) Khoshnevis B (2004) Automated construction by contour craftingmdashrelated robotics and
information technologies Automation in construction 13(1) 5-19
48) R Alice (2019) CRYSTAL PALACE SHOWER TALK httpsbloginoxstylecomencrystal-
palace
49) Eba (2014) HISTORY ldquoballoon framingrdquo the first prefabricated building system (US)
Architecture for the 99 httpslikemyplacewordpresscom20140214history-balloon-
framing-the-first-prefabricated-building-system-us
50) Peter Goumlssel Arnt Cobbers Oliver Jahn (2012) A Brief History of Prefab ArchitectureWeek
httpwwwarchitectureweekcom20121003design_1-1html
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
93 | P a g e
51) Merin G (2018) AD Classics Habitat 67 Safdie Architects ArchDaily
httpswwwarchdailycom404803ad-classics-habitat-67-moshe-safdie
52) Sveiven M (2018) AD Classics Nakagin Capsule Tower Kisho Kurokawa ArchDaily
httpswwwarchdailycom110745ad-classics-nakagin-capsule-tower-kisho-kurokawa
53) Modular Building Experience | Deluxe Modular (2020)
httpswwwdeluxemodularcomexperience
54) Applications | Modular Construction | Bathroom Pods (2020) Howick Ltd
httpswwwhowickltdcomapplicationsmodular-constructionbathroom-pods
55) Project types (2018) Panel built httpswwwpanelbuiltcomblogmodular-building-types
56) Mobile Mini Merger - WillScot (nd) Willscot httpswwwwillscotcomAboutMobile-
Mini-Merger
57) Teague L (2017) Urbantainer breaks down the negative stereotypes of modular building
Frameweb httpsframewebcomarticleurbantainer-breaks-down-the-negative-
stereotypes-of-modular-building
58) Modular construction (nd) SteelconstructionInfo
httpswwwsteelconstructioninfoModular_construction
59) Modular V (2020) What Is Modular Building Construction Your Ultimate Guide Vanguard
httpsvanguardmodularcomabout-modular
60) Permanent Modular Construction Annual Report 2019 | Modular Building Institute (2019)
MBI httpswwwmodularorgHtmlPageaspxname=pmc-2019-home
61) Modular Construction Foundation (2020) Triumph Modular
httpswwwtriumphmodularcomabout-triumphour-servicesconstruction-
managementfoundations
62) Weights and Dimensions (2020) ITF httpswwwitf-oecdorgweights-and-dimensions
63) Sajip J (2019) Modular Construction A Sustainable Building Method NY-Engineers
httpswwwny-engineerscomblogmodular-construction-a-sustainable-building-
methodWeights and Dimensions (2020 August 28) ITF httpswwwitf-oecdorgweights-
and-dimensions
64) Muresan F (2019) What is Modular Construction NY-Engineers httpswwwny-
engineerscomblogwhat-is-modular-construction
65) ADVANTAGES of using SurePods prefabricated modular bathroom pods (nd) SurePods
httpswwwsurepodscomspeed
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
94 | P a g e
66) EasyPads - The easy-to-use foundation system for modular buildings (2019 March 23)
EasyPads - Foundation System httpseasypadscouk
67) Honrubia M amp Mendonccedila A (2019 June 18) The Benefits of Reusable and Modular
Constructions Ennomotive httpswwwennomotivecomreusable-modular-
constructions
68) Cosentino (2020) Discover Cosentino and all the characteristics of its materials
httpswwwcosentinocom
69) Al-Hussein M Manrique J D amp Mah D (2009) North Ridge CO2 analysis report
comparison between modular and on-site construction University of Alberta Canada
70) Vickers H (2017) Modular construction 4 health and safety benefits Building 4 Education
httpsb4edcomArticlefour-health-and-safety-benefits-of-modular-construction
71) PRISM (2020) HGA and The Boldt Company build STAAT ModTM critical care units to
address the COVID-19 hospital bed shortage PRISM Modular construction 4 health and
safety benefits Building 4 Education httpsb4edcomArticlefour-health-and-safety-
benefits-of-modular-construction
72) Harrouk C (2020 September 28) Mayor of London Launches Housing Design App to
Transform Construction ArchDaily httpswwwarchdailycomauthorchristele-harrouk
73) Schoenborn J (2012) A case study approach to identifying the constraints and barriers to
design innovation for modular construction (Doctoral dissertation Virginia Tech)
74) Casas prefabricadas inHAUS (nd) servicio post-venta casa modular archivos InHAUS
httpscasasinhauscomfranceestagservicio-post-venta-casa-modular
75) Catalunya U U P (nd) MIVES mdash Departamento de Ingenieriacutea Civil y Ambiental mdash UPC
Universitat Politegravecnica de Catalunya UPC httpsdecaupceduesproyectosmives
76) Kim D (2008) Preliminary Life Cycle Analysis of Modular and Conventional Housing in
Benton Harbor MI (Doctoral dissertation)
77) Gangolells M Casals M Forcada N amp Macarulla M (2014) Analysis of the
implementation of effective waste management practices in construction projects and sites
Resources conservation and recycling 93 99-111
78) Alarcon B Aguado A Manga R amp Josa A (2010) A Value Function for Assessing
Sustainability Application to Industrial Buildings Sustainability 3(1) 35ndash50
httpsdoi103390su3010035
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
95 | P a g e
Anexo 1
a) Indicators resources
o Prefabricated Steel Modular (PSM)
Table A1 1 ndash Cost of project PSM (Hammad 2019)
Table A1 2 -Time of project PSM (Hammad 2019)
Table A1 3 - Energy utilized during construction (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
96 | P a g e
Figure A1 1 - Injury risks for workers (Hammad 2019)
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
97 | P a g e
Figure A1 3 - Co2 amount (Aye 2011)
o Prefabricated Concrete Modular (PCM)
Figure A1 4 - Total project cost (Balasbaneh 2020)
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
98 | P a g e
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter)
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020)
o Prefabricated Timber Modular (PTM)
Figure A1 8 - Co2 emission (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
99 | P a g e
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
o Traditional Reinforced Concrete (TRC)
Table A1 6 6 - Projects cost (Hammad 2019)
Table A1 7 - Projects schedule (Hammad 2019
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
100 | P a g e
Table A1 8 - Energy utilised during construction process (Hammad 2019)
Figure A1 9 - Injury risks for workers (Hammad 2019)
Figure A1 10 - Noise level (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
101 | P a g e
Figure A1 11 - Greenhouse gas emission (Aye 2011)
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
102 | P a g e
Anexo 2 1 Survey Q amp A
Q How many years of experience do your company have in modular construction
industry Table A2 1 - Professional experience of the company
Company Responses
A 10-15
B 10-15
C 20-30
D 20-30
E 30-50
Q How many years of experience do you have in the modulartraditional construction
and what is your job position Table A2 2 - Personal experience of participant
Company Responses
A 15 years
B 13 years sales manager
C 30 years of which the last 25 have been as design architect
D Quantity Surveyor
E 3 years Foreign Trade Manager
Q What types of modules your company products in terms of material Table A2 3 - Type of modules
Company Responses
A Wood Steel
B Wood
C Wood
D Wood
E Counter and Fibber cabins Steel
Q Which types of projects you did so far Table A2 4 - Type f projects
Company Responses
A Residential houses
B Schools Residential houses Commercial buildings
C Residential houses
D Schools Residential houses Hospital Commercial buildings
E Schools Residential houses hospital Commercial buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
103 | P a g e
Q Num of employees num of factories and num of modules build Table A2 5 - Characteristics of production range
Company Responses
A 80 employees 1 factory 200 modsyear
B 130 1 490
C 15
D 50 Employees 2 factories 80 build
E 250 employees 2 factories 100000 m2 prefabricated 5000 containers 1000 cabinets TURKEY
Q What was your motivation to choosework in modular construction Table A2 6 - Motivation for doing modular construction
Company Responses
A High demands in market and lack of provide Innovation
B Economic profit
C Environmental benefits High demands in market and lack of provide Innovation Shorter construction schedule due to need Economic profit
D Shorter construction schedule due to need Innovation
E Economic profit
Q Do you have sup-contracts for your panels or they had built in your factories what
is the reason for this decision Table A2 7 - Panel production conditions
Company Responses A build our own
B PE design and approvals fire suppression design and installation ceramic tile Energy Star design and inspection are all subcontracted
C All built in house in our own workshop We have developed our own unique systems which are not available elsewhere
D build in factory - programme cost
E
EPS isolated panels are produced in our factories The other are being purchased from domestic market Standard is EPS isolation and its fixed costs are lower because of quantity The others are not standard investment in production is not feasible
Q What is the level of automation technologies you use in off-site and on-site
production and assembly Table A2 8 - Level of automation
Company Responses
A Extraordinarily little today investing in this heavily this year want to get to 80
B 20
C Off-site 60 on site 20
D 20
E 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
104 | P a g e
Q Does A modular project have a smaller number of labours Less wages of salary off-
site and on-site due to specialization of workforce Does the more value added in
each hour of work can compensate Table A2 9 - Laboral status
Company Responses
A Fewer labour hours and at less cost per hour 1 hour in the factory is equal to 4 on site
B Prefabricated systems-built modular construction generally has a smaller on-site labour force for a shorter period
C Labour similar but more efficient working off site
D Yes (less no of workers and wages) - no need for special work force
E -
Q Do you have any case of recycle and reuse the structuralnon-structural elements in
your projects Table A2 10 - Recycle and Re-use
Company Responses
A Yes
B Yes
C No
D No
E Yes
Q Do you upgrade the modules with other environmentally friendly technologies such
as solar panels in your projects Please give us some examples Table A2 11 - Innovative technology integration
Company Responses
A Our homes are all self-powered only company in the world to be doing this
B
This factory allows for site installation of solar panels and other energy savings processes on site by the independent builderbuyer of our modular building materials Modular makes the most sense to be used by architects and builders with environmentally friendly tech
C
Modules (flat packed floor wall and roof components) are constructed of ply and highly insulated with non-petroleum-based insulation (recycled glass as a fibre) Solar panels fitted as an add on to completed building
D None yet not been asked
E Solar technology is YES
Q Automation in off-site production generates less or more waste of material There
are some argues about less waste generation in manual activities because of better
sense of material resistance by normal labour (wooden material for instance) Table A2 12 - Automation status on waste generation
Company Responses
A we are not automated yet but believe automation will be much more efficient use of materials
B In our experience as a custom modular manufacturer automation has a significant cost that may not be recoverable for many months if not years- millions of dollars in cost of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
105 | P a g e
components set up and training versus hourly wage and benefits of trained factory workers
C Waste is much reduced and a proportion of the waste is remanufactured to smaller items or sold on to handymen
D Would be less waste but we do not use much automation
E -
Q How much reduction does off-site modular construction has in generating ldquowasterdquo in
comparison with traditional construction methods Table A2 13 - Reduction of waste
Company Responses
A 70 less waste
B I am unable to provide an answer to this question
C
As we are timber people emissions are low regardless of construction methods Steel and concrete use are kept to a minimum and these are the high emission materials
D We are still working on our carbon footprint
E 15 less carbon emission
Q How much reduction has in ldquoenergy consumptionrdquo off-site in comparison with
conventional on-site construction What about during the operation phase Table A2 14 - Energy consumption status
Company Responses
A Our homes are not positive from an energy perspective
B
Energy consumption of a factory is known and relatively constant on a weekly monthly and annual basis The modular components for a two-box ranch style house require 3 workdays on our factory floor and 4 more days in final finish prior to shipment A competent and experienced modular builder can many times finish the entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-built house could require as much as 4 months for the same completion
C Not assessed but doubt there is much difference
D We are still working on our carbon footprint
E 30 energy saving
Q Did you deliver any projects for providing emergency services in Covid-19 period You
can mention the projects in the other section Table A2 15 - Delivery of projects in COVID-19 pandemic period
Company Responses
A No
B No
C No
D No
E Yes
Q Did you construct any projects for world aid organizations and charities You can
mention them in the other section
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
106 | P a g e
Table A2 16 - Aid organization project delivery
Company Responses
A No
B No
C No
D No
E Yes
Q Do you offer post-sale services to your clients Table A2 17 - Post-sale services to client
Company Responses
A Yes
B No
C Yes
D Yes
E Yes
Q How much was your initial costs estimate (Factory set up etc) How long was the
investmentrsquos payback period Table A2 18 - Initial costs
Company Responses
A 20 million Canadian dollar 5-year payback
B What costs Factory set up or cost of modular product sold to builders What about labour engineering transportations etchellip
C The business has been building up over decades so it is not possible to isolate specific costs
D -
E 15 million USD 5 years
Q Which factors can change the initial costs Table A2 19 - Effective factors on initial costs
Company Responses
A Level of automation Product types and production range Less sub-contracts Site location
B Design of modular building- ie roof system high wind heavy snow loads etchellip Product types and production range Site location
C Financing Level of automation Product types and production range Less sub-contracts
D Level of automation Product types and production range Site location
E Level of automation Product types and production range
Q Can component re-use building portability and the life cycle value of materials be
used as a strategy to ldquocompensaterdquo for higher initial construction costs Table A2 20 - Re-use effect on budget
Company Responses
A -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
107 | P a g e
B
We use many lumber cut-offs PVC drainpipes and conduit and dry wall pieces over many modular orders Unusable drywall shingle and PVC pieces are collected and sent out for recycling Wood is collected and recycled into mulch product or used for heating by others
C Not easily Our methods (flat pack) due not lend themselves to building portability
D -
E 50 years life span of the products
Q Which factors did you consider for choosing modular construction over traditional
method Table A2 21 - positive factors about modular construction to be chosen
Company Responses
A traditional construction is broken
B
Speed ease and cost of overall construction Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
C Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
D Transportation costs and boundaries Local salary wages
E Transportation costs and boundaries Local salary wages Environmentally friendly
Q Do use BIM in your projects what are the challenges in using BIM Table A2 22 - Use of BIM in projects
Company Responses
A 100 BIM from conceptual to finished models
B No
C No
D No
E No
Q What effects the production line can have on the design Are there any boundaries
on the architectural design Table A2 23 - Influence of production line on design
Company What effects the production line can have on the design Are there any boundaries on the architectural design
A No you just need to design with our subassemblies in mind
B This factory maximum module dimension capability is 15rsquo9
C Workshop prefabrication gives the architect far more design freedom
D Width of building for transport to make economically viable
E No
Q Is there any lack of knowledge from architects or design engineers in modular industry
about production line processes transportation limitations etc
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
108 | P a g e
Table A2 24 - Lack of knowledge among experts
Company Responses
A Yes
B No
C NA
D Yes
E Yes
Q How state transport regulation and approval can harm the projects in cost and time
Have you experience delays in your schedules because of those Table A2 25 - Transportation regulation effect on projects
Q Does the concept of transportable materials add extra costs on the project Do the
reduction of material waste and multiple discounts can ldquocompensate the lossrdquo Table A2 26 ndash Transportable material choice and its effects
Company
Does the concept of transportable materials add extra costs on the project Do the reduction of material waste and multiple discounts can ldquocompensate the lossrdquo
A Transportation costs are offset by speed of production and reduced financing costs for the project
B Not significantly
C See 26 The reverse applies
D No
E No
Q What are the difficulties in using automation in off-site production processes Table A2 27 - Challenges of using automation
Company Responses
A Codding Integration with advanced software
B Cost
C -
D Integration with advanced software
E Codding Cost Lower salaries of manual processes by labour
Company
How state transport regulation and approval can harm the projects in cost and time Have you experience delays in your schedules because of those
A Yes Some areas are slow to respond
B
Yes Some states in the US are more difficult to ship oversized and ldquosuper loadsrdquo through This adds both time and expense to the projects
C No Our company prefabricates and flat packs so all components are within or close to legal load limits
D No
E Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
109 | P a g e
Q Which problems exist in modular construction in terms of contracts What are the
solutions Table A2 28 - Contract condition in modular industry
Q What are the challenges in defining responsibilities among participants of a project
due to the changing most of the activities to precast solutions Table A2 29 - Participation status in modular projects
Company
What are the common errors than can harm the synchronization of productivity between off-site production transportation and on-site installation progress For instance less demands on-site caused
A Lack of quality partners on site that see the benefits of modular and therefore increase their pricing
B
The builder owns the responsibility to ensure that site work is done on time and correctly Delays in this can result in postponed transport of product and interest through demurrage charges
C Provided control is tight none
D -
E -
Q Considering all components are prefabricated offsite what is the role of an outside
general contractor Table A2 30 - Role of outside general constructor
Company Responses
A will always need some component of site work to complete the project
B
An outside general contractor is the independent builder The modular factory is a material vendor to the general contractor The general contractor is responsible for all site work and permits as well as storage- installation- and finish of the modular product forming the house or structure they are building
C We do not use outside general contractors All stages from earliest concept design to completed building are in house
Q How often advantageous changes must be done in the production line and what are
the challenges
Company Which problems exist in modular construction in terms of contracts What are the solutions
A Every state has a different building code need a universal code
B
In some cases the end home buyer believes the factory to be the builder and the actual independent builder to be a sales agent for the factory Our company addresses this through accuracy in the relationship described on our website and social media as well as requiring the builders customer to sign a disclosure acknowledgement from that describes the relationship in detail
C Banks do not recognise work done until it is erected on site This creates cash flow pressure where bank finance is involved
D -
E Delivery on time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
110 | P a g e
Table A2 31 - Changes in production line and its effects
Company Responses
A Slows down production
B This company incorporates changes to product materials or procedures between orders A change in process will not occur that affects only some of the components of an order
C Not sure I can answer that ion the space All means of production have advantages and challenges We have chosen methods and stick to them
Q Do you have sub-contracted players involved in your project for site preparation and
foundation phase etc why Table A2 32 - Site preparation status
Company Do you have sub-contracted players involved in your project for site preparation and foundation phase etc why
A Yes Because we are selling in many geographic areas we need local representation
B No This is the responsibility of our customer- the general contractorindependent builder
C Yes Under direct supervision Their equipment is expensive and not portable It makes sense to use local contractors for footings
D -
E Yes
Q If the onsite foundation is constructed by an outside general contractor are there
additional challenges at the interface in terms of a technology gap the equipment or
tools used the construction experience of workers or in scheduling and phasing of
construction Table A2 33 - Challenges with sub-contractors for site preparation phase
Q What are the wrong perceptions about modular products among market and public Table A2 34 - Wrong perceptions for modular products
Company What are the wrong perceptions about modular products among market and public
A that their only quality is being cheaper
B
In the USA many people the media and even professional engineers do not understand the capabilities of modular construction Many people continue to confuse this form of construction with HUD on frame products
C With our methods (flat pack) that prefabrication reduces the design options The reverse is the case
Company
If the onsite foundation is constructed by an outside general contractor are there additional challenges at the interface in terms of a technology gap the equipment or tools used the constructionhellip
A we need to educate most local subs on our process and reason for doing things a certain way
B Not that directly affects the factory
C No
D -
E -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
111 | P a g e
Q What strategies are taken among manufacturers to either improve the public
perception of modular construction or to promote its advantages to architects and
potential clients Table A2 35 - Solutions for wrong perceptions
Company
What strategies are taken among manufacturers to either improve the public perception of modular construction or to promote its advantages to architects and potential clients
A Going fast Proving the superior nature of our homes by getting more of them into the world
B
There is some cooperation between builders manufacturers architects and engineers to educate the public The national entity is the Modular Home Builders Association See httpswwwmodularhousingcom
C Nothing specific We advertise our advantages and it is enough
Q Any other challenges and recommended solutions for them that you want to add
please Table A2 36 - Recommendations
Company Responses
A -
B -
C The capital cost of equipment Specialised digital equipment is expensive making it difficult for small and medium companies to enter the market
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Masterrsquos Degree
Title
Author
Tutor
Speciality
Department
Date
PUJADAS AacuteLVAREZ PABLO
-
September 2020
Structural and Construction Engineering
Modular construction and overview on its potential advantages
and constraints in the project management perspective
MASOUD VEISKARAMI
EPC - Department of Project and Construction Engineering
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Dedication
To my brother Milad one of the best executive civil engineers that I have ever seen who was and will be my role model and inspiration in construction world
دنیای در من بخش الهام و الگو که ام دیده تاکنون که اجرایی عمران مهندسین بهترین از یکی میلاد برادرم به تقدیمبود خواهد و بوده ساز و ساخت
To my parents Professor Kiomars VeisKarami who is my inspiration to pursuit post-education to be an ideal professor like him Ashraf Ahmadi who cherished and supported me all the way I am thankful for all your favours
استاد یک تا است عالی تحصیلات پیگیری برای من بخش الهام که کرمی ویس کیومرث پروفسور مادرم و پدر هب شما لطف از کرد حمایت من از و داشت گرامی مرا زندگی طول تمام در که احمدی اشرف باشم او مانند آل ایده
سپاسگزارم
To dear my friends and classmates Ali Sasani loveable Sofia and genius Junior who always were next to me and will be in my heart
من کنار در همیشه که عزیز جونیور و داشتنی دوست وفیاس ساسانی علی عزیزم های همکلاسی و دوستان برایبود خواهند من قلب در و بودند
To my valuable professors specially Professor Pablo Alvarez Pujadas who guided me to direction that helped me to discover a new perspective of civil engineering that I always was looking for
A mis valiosos profesores en especial al profesor Pablo Alvarez Pujadas quien me guioacute
hacia una direccioacuten que me ayudoacute a descubrir una nueva perspectiva de la ingenieriacutea
civil que siempre estuve buscando
To my language teachers Mr Roozbeh Kargar who made me able to write this dissertation in the most academic way without any obstacles Ms Shafie and Ms Ismaili who shared their knowledge of Spanish to help me through the courses to achieve great marks and improve my knowledge
هیچ بدون روش ترین اکادمیک به را نامه پایان این بتوانم من شد باعث که کارگر روزبه استاد من زبان اساتید به به را خود اسپانیایی زبان دانش که اسماعیلی خانم سرکار و یشفیع خانم سرکار محترم اساتید بنویسم مانعی
بهبود را خود دانش و آورم بدست را عالی نمرات تا کنند کمک من به آموزشی های دوره در تا گذاشتند اشتراکبخشم
ایرانی باد زنده ایران باد زنده
28092020
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Abstract
During past century construction industry is suffering from a poor productivity rate in
comparison with the other industries To solve this problem the concept of industrialization in
construction was introduced which Modular construction is one of its methods with a not short
history However during past decade had changed its nature to be used for longer lifetime as
permanent uses
The purpose of this study is to identify the possible advantages and investigate on common
challenges related to modular construction industry in a project management perspective and intend
to find adequate solution for them The methodology of this study is a combination of quantitative
and qualitative based approaches
A multi-criterion decision-making software (MIVES) was used to measure the functionality of
advantages and their effect on final decision to use ether three modular alternatives (Steel timber
and concrete) or a traditional reinforced concrete method for building a residential project The results
showed that despite few poor performances in two environmental criteria (CO2 emission amount and
Embodied energy used during construction) in general all three modular alternatives had overcome
traditional option in every requirement where prefabricated timber modular method became the
most sustainable alternative This result can confirm the positive effect of modular construction
advantages and show its superior nature over conventional construction
In addition a qualitative online survey form was sent to modular players to confirm the
identified benefits discussion about common challenges and receive recommendations and solutions
to solve them The responds were collected from five companies with the average of 20 years of
experience in modular construction which illustrated that the advantages can be achieved in real
projects as well as the literature review and study cases on decision making process identified
On the other hand there are challenges remaining without resolution such as Lack of
partnership among participants of project conflicts by local codding in use of automation wrong
perceptions of market etc
The possible solutions could be creating an international code for modular products
advertisement on potential advantages of modular method in publicmarket updating the contract
condition and most important of all improving the cooperation between scientific investigators and
off-site industry to motivate and provide the researchers with more real data to prevent contrasts in
hypothesises and find more innovative solutions1
Keywords Sustainability Modular construction Embodied energy Prefabrication Lifecycle assessment (LCA) Building information modelling (BIM) MIVES Productivity rate Standardization
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table of Contents Table of Contents 2
1 Introduction 1
Motivations 1
Orientation of previous studies 1
Gap of knowledge 1
Objectives of the study 2
Survey among the professionals in the modular industry by Online Form 2
Decision-making among three modular methods and conventional option by MIVES 2
Limitations 2
Lack of existence of references related to the subject 2
Non-accessible information from companies and scientific articles 2
Obstacles caused by global lockdown during covid-19 pandemic 2
Organization of the thesis 3
2 State of the art 4
Productivity problem in construction industry 4
Status of productivity rate of construction industry among other industries 4
Reasons of poor productivity 6
Solutions for improvement 7
Brief on modular construction 10
History of modular construction 10
Types of modular product 15
Module architectural types 15
Module structure types 22
Types of modular buildings based on operation period 27
Common uses of modular buildings in the market 27
Construction phases 28
Literature review on possible advantages 31
Scheduling benefits 31
Economic benefits 34
Environmental Benefits 36
Health and security benefits 38
Social-Laboral benefits 39
Modular Construction role in COIVD-19 Pandemic 40
Review on common challenges 41
Initial costs 41
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Architectural challenges 43
Transportation challenges 44
Wrong perceptions among public and real estate market 45
Integration of advanced software 46
Redefining the contracts 46
Supply chain-transportation-onsite assembly management errors 47
3 Common challenges in modular construction industry by a survey 48
Methodology 48
Objective 48
Role of the researcher 48
Ethical considerations 48
Survey setting 48
Development of questionnaire 49
Participant profile 50
Experience amp professions 50
Data collection 51
General information 51
Economic issues 52
Environmental status 52
Social Benefits 53
Initial costs 54
Design limitations 55
Transportation Limitations 55
Project management challenges 56
Social challenges 57
Data analysis amp conclusions 57
Advantages 57
Challenges discussion 58
4 Decision making based on potential advantages among three modular alternatives and
conventional construction method in a project by MIVES software 60
Methodology 60
Objective 60
What is MIVES 60
Data collection process 60
Case Study references 60
Input data 65
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Final indicators 69
Weights 73
Data analysis 76
Indicators Values 76
Criteria Values 77
Requirement Values 81
Sustainability Values (Final decision) 83
5 Conclusions 84
Decision making process 84
Conclusions and discussion 84
ECONOMIC ndash TIME discussion 84
ENVIRONMENTAL discussion 84
SAFETY AND SOCIAL dominance by modular methods 85
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES 85
Effective external factors on decision 86
Future studies 86
Decision making study on two real projects with the input data of professional
modular and traditional constructors 86
Technological studies about the production line of a modular off-site plant by factory
and on-site visits 86
A survey about challenges in modular construction and its possible solutions to find
adequate solutions 86
Recommendations 87
Cooperation between industrial players and scientific researchers in offsite
construction 87
Education about industrialization in construction and its alternatives 87
Establishing international and regional adequate codes 87
Synchronizing the contract conditions with modular construction conditions 87
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc 88
Changes in financial strategies and adapting them with off-site construction nature 88
6 References 89
Anexo 1 95
Anexo 2 102
1 Survey Q amp A 102
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study 4
Figure 2 2 - UK productivity status (Office for National Statistics -ONS) 5
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS) 5
Figure 2 4 - Value added comparison among industries (ennovacom) 6
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom) 6
Figure 2 6 - Fragmentations between construction industry players and their various productivity
rates (McKinsey 2019) 7
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom) 8
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom) 9
Figure 2 9 - Digital construction organization (wwwbimcommunitycom) 9
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom) 10
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom) 11
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom) 11
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8
meters (modulartch) 12
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau) 13
Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
14
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom) 15
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom) 16
Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom) 17
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom) 17
Figure 2 20 - Production steps of floor cassette to walls and their attachment together
(wwwhowickltdcom) 18
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom) 19
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom) 19
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom) 20
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom) 20
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom) 21
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-
Malec (wmengcom) 21
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo) 22
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
23
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported
module (wwwsteelconstructioninfo) 24
Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the
lower levels (wwwsteelconstructioninfo) 25
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other
metals (vanguardmodularcom) 26
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma
Beton) 26
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction
report MBI 2019) 28
Figure 2 34 - Overlaps of phases in modular construction project 29
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom) 30
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method
(McKinsey amp Company 2019) 31
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom) 33
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom) 33
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes) 34
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom) 34
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk) 35
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images) 36
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site
(wwwcadoltocom) 37
Figure 2 44 - various layers of a module building unit including insulations
(wwwsteelconstructioninfo) 38
Figure 2 45 - Compartment floor at junction with external wall and compartment wall
(wwwsteelconstructioninfo) 39
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use
inside convention centres arenas and temporary structures Image courtesy of HGA and The Boldt
Company (prismpubcom) 40
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The
Boldt Company 40
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction
(archdailycom) 41
Figure 2 49 -Balance between Initial costs and Economical benefits 42
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects
(casasinhauscom) 46
Figure 2 51 - synchronization between supply chain transportation and on-site assembly 47
Figure 3 1 - Online office forms for survey use 49
Figure 3 2 - Questionnaire development 50
Figure 3 3 - Participants motivations to start a modular company 51
Figure 3 4 - Re-use potential 53
Figure 3 5 - Contribution in Covid19 epidemic 53
Figure 3 6 - Post sale services por future clients 54
Figure 3 7 - effective factors in initial investments for start-up companies 54
Figure 3 8 - Lack of knowledge among designers and engineers 55
Figure 3 9 - challenges of using automation in off-site plants 56
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study
(WAHammad 2019) 61
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and
conventional methods (Akbarnezhad 2019) 61
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020) 62
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017) 62
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad
2017) 63
Figure 4 6 - Architectural section of multi-residential building (Aye 2011) 63
Figure 4 7 - Structural elements used in modules (Aye 2011) 64
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012) 64
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES) 65
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM
alternatives 71
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software 74
Figure 4 12 - Possible forms of the value function 75
Figure 4 13 - Value function for total project cost in MIVES 75
Figure 4 14 - Criteria normalized values 77
Figure 4 15 - Project Schedule 78
Figure 4 16 - Waste generation ratios 78
Figure 4 17 - CO2 Emission normalized values 79
Figure 4 18 - Recyclability and re-use potential of alternatives 79
Figure 4 19 - Embodied energy consumption and saving potential by reuse 80
Figure 4 20 - Safety advantage of modular construction over traditional method 80
Figure 4 21 - Social criteria 81
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values
analysed by MIVES 81
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind 82
Figure 4 24 - Modular dominance in safety and social requirements over conventional option 82
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives 83
Figure A1 1 - Injury risks for workers (Hammad 2019) 96
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
96
Figure A1 3 - Co2 amount (Aye 2011) 97
Figure A1 4 - Total project cost (Balasbaneh 2020) 97
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
97
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter) 98
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020) 98
Figure A1 8 - Co2 emission (Aye 2011) 98
Figure A1 9 - Injury risks for workers (Hammad 2019) 100
Figure A1 10 - Noise level (Hammad 2019) 100
Figure A1 11 - Greenhouse gas emission (Aye 2011) 101
Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo) 23
Table 2 2 - Possible benefits in projects scheduling 32
Table 2 3 - Economic benefits in modular method 35
Table 2 4 - Environmental Benefits 37
Table 2 5 - Health and safety amp Social-Laboral advantages 39
Table 3 1 - Participantrsquos profiles 50
Table 4 1 - Requirement tree with all indicators which considered for decision making process 67
Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed
to be done on them 68
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other
studied 68
Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow) 68
Table 4 5 - Qualitative indicators 69
Table 4 6 - First hand data over literature 69
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow) 70
Table 4 8 - First hand data over literature 70
Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue) 70
Table 4 10 - First hand data over literature 70
Table 4 11 - Final indicators for PCM 72
Table 4 12 - TRC first-hand data over literatures 72
Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow) 72
Table 4 14 - Final Quantitative indicators used for decision making process 72
Table 4 15 - Requirement weights 73
Table 4 16 - Weights of criteria 73
Table 4 17 - Value function for indicators in MIVES 76
Table 4 18 - Indicators normalized values 76
Table 4 19 ndash Indicator normalized values 76
Table 4 20 - Criteria normalized values 77
Table 4 21 - Criteria normalized values 77
Table 4 22 - Requirement normalized values for four indicators 81
Table 4 23 - SI (Sustainability Indexes related to four alternatives) 83
Table A1 1 ndash Cost of project PSM (Hammad 2019) 95
Table A1 2 -Time of project PSM (Hammad 2019) 95
Table A1 3 - Energy utilized during construction (Hammad 2019) 95
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 96
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 99
Table A1 6 6 - Projects cost (Hammad 2019) 99
Table A1 7 - Projects schedule (Hammad 2019 99
Table A1 8 - Energy utilised during construction process (Hammad 2019) 100
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011) 101
Table A2 1 - Professional experience of the company 102
Table A2 2 - Personal experience of participant 102
Table A2 3 - Type of modules 102
Table A2 4 - Type f projects 102
Table A2 5 - Characteristics of production range 103
Table A2 6 - Motivation for doing modular construction 103
Table A2 7 - Panel production conditions 103
Table A2 8 - Level of automation 103
Table A2 9 - Laboral status 104
Table A2 10 - Recycle and Re-use 104
Table A2 11 - Innovative technology integration 104
Table A2 12 - Automation status on waste generation 104
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table A2 13 - Reduction of waste 105
Table A2 14 - Energy consumption status 105
Table A2 15 - Delivery of projects in COVID-19 pandemic period 105
Table A2 16 - Aid organization project delivery 106
Table A2 17 - Post-sale services to client 106
Table A2 18 - Initial costs 106
Table A2 19 - Effective factors on initial costs 106
Table A2 20 - Re-use effect on budget 106
Table A2 21 - positive factors about modular construction to be chosen 107
Table A2 22 - Use of BIM in projects 107
Table A2 23 - Influence of production line on design 107
Table A2 24 - Lack of knowledge among experts 108
Table A2 25 - Transportation regulation effect on projects 108
Table A2 26 ndash Transportable material choice and its effects 108
Table A2 27 - Challenges of using automation 108
Table A2 28 - Contract condition in modular industry 109
Table A2 29 - Participation status in modular projects 109
Table A2 30 - Role of outside general constructor 109
Table A2 31 - Changes in production line and its effects 110
Table A2 32 - Site preparation status 110
Table A2 33 - Challenges with sub-contractors for site preparation phase 110
Table A2 34 - Wrong perceptions for modular products 110
Table A2 35 - Solutions for wrong perceptions 111
Table A2 36 - Recommendations 111
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
1 | P a g e
1 Introduction
Motivations
Construction industry is suffering for a poor productivity problem during the past 60 years in
comparison with other industries and industrialization in construction was suggested by the
investigators to improving the construction performance by applying production technologies and
design standardized products to be built in off-site plants By searching over the off-site methods
modular construction was found which is benefiting its high sustainability and productivity in
comparison with traditional construction approaches
One of the motivations of these study is to study the advantages of modular construction in
order to demonstrate the superior nature of modular construction over traditional methods to be
presented as a reasonable solution for productivity problem the However there are various of
opinions and argues about the beneficiary of this method so that it was decided to analyse them more
deeply in construction management perspective and even get into contact with the industry for
professional confirmation
Another motivation of this study was to contribute to development of modular construction
and find what is holding it back from developing by discovering the challenges in the modular
construction industry and find possible solutions to help for growth
Orientation of previous studies
During past two decades fewer studies in comparison with other innovative methods have
focused on this subject to analyse this method in economic environmental and functional areas to
discover the benefits and make comparisons with traditional construction methods where possible
McKinsey amp company report on 2019 had general overview on its potential advantages challenges
and its ability to raise the productivity in construction processes while introducing the benefits by
making comparisons in projectrsquos schedule budget and environmental performance among modular
and traditional methods and finally shedding a light on dark side which are the obstacles of growth in
industry and then suggesting possible solutions for improvements In addition there are numbers of
articles focusing on the environmental performance of modular buildings by doing Lifecycle
assessment (LCA) analysis on emissions waste generations and consumption primary resources etc
(Mohammad Kamali and Kasun Hewage et al 2016)
On the other side there are studies that made comparisons between traditional and modular
methods of construction to build a specific project based on BIM models and professional data bases
which led to great results that showed numbers of advantages (AWA Hammad et al 2019) (L Aye
et al 2011) (Ali Tighnavard Balasbaneh at Springer-Verlag 2020)
Gap of knowledge
Taking into account of existent researches there is a gap of knowledge which leads to few
questions that still have remained without answer
bull Confirmation of these benefits that came from scientific researches by professional
players in the industry
bull Do these advantages effect the final decision to choose modular method over
conventional way
bull What are the needs of the market that could be as motivations to use modular
construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
2 | P a g e
bull What are the challenges in the industry in the professional point of view
bull Do the solutions that suggested by researchers can be applied in real projects What
are their professional solutions
Objectives of the study
The importance of this study is to resolve the mentioned questions by accomplishing the
studyrsquos objectives that are separated to be achieved by two methods which are qualitative and
quantitative
Survey among the professionals in the modular industry by Online Form
bull To confirmcorrect the data from literature reviews about benefits of modular
construction
bull Their motivations and reasons to choose modular method
bull What are the constraints and obstacles that they are facing
bull Recommendations and solutions for these problems
Decision-making among three modular methods and conventional option by MIVES
bull To discover the advantages in real study cases by comparisons between four
alternatives
bull To examinate the functionality of every alternative in several criterions
bull How much effective these benefits can be in the final decision based on the
requirements of market and their priorities
Limitations
Several obstacles were seen during the study that effected the methodology and input data
significantly Here are some examples
Lack of existence of references related to the subject
Because of the subjectrsquos novelty or less focus the quantity of references is not enough to
cover all the dimensions of study therefore few estimation hypothesis (that were proved by the
results at the end) and consultants with experts were used instead to provide the necessary
information In addition many of the scientific reports and articles were published few months or
even days before the studyrsquos conclusions so that it was decided to be used immediately to improve
the studyrsquos liability
Non-accessible information from companies and scientific articles
There are innovative companies that because of their privacy policies and protection of
innovation could not provide the necessary data about their projects by request even for academic
uses
On the other side scientific papers in some cases were protected and did not have open
access not even with educational access permissions as requests have been denied by the authors
Obstacles caused by global lockdown during covid-19 pandemic
One of the unpredicted challenges that happened during the study was the virus pandemic
that affected the world negatively and this study was not an exception From on-site project and off-
site factory visits interviews with experts in the industry etc were cancelled Numbers of regions went
to full shutdown including offices factories etc which resulted in reduction of participations in online
survey form as well Therefore it was decided to select five most suitable participants to be analysed
instead of planed massive quantity of results
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
3 | P a g e
Organization of the thesis
⎯ Chapter two state of the art explaining the productivity problem history types and
phases of modular construction and literature reviews on benefits and challenges
⎯ Chapter three The online survey among modular players in the industry
⎯ Chapter four MIVES multi-criteria decision-making approach
⎯ Chapter five Conclusions and findings
⎯ Chapter six Recommendations
⎯ Chapter seven references
⎯ Anexo A (Input data references)
⎯ Anexo B (Survey QampA) 2
Kewwords Sustainability Modular construction MIVES Productivity rate Prefabrication Lifecycle assessment (LCA)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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2 State of the art Productivity problem in construction industry
Status of productivity rate of construction industry among other industries
It has been decades that construction industry is far behind the other industries in terms of
productivity rates Attempts had been done by innovative players in the industry but still the
difference is too enormous which the demands for improvement are needed
Globally construction sector labour-productivity growth averaged 1 percent a year over the
past two decades compared with 28 percent for the total world economy and 36 percent for
manufacturing If construction productivity were to catch up with the total economy the industryrsquos
value added could rise by $16 trillion a year (McKinsey 2019)
It can be said that the building industry is one of the key industries in the general economy
The construction sector typically comprises 8-10 of the Gross Domestic Profit (GDP) of a Western
economy (McGeorge amp Palmer 2002) Therefore only 10 improvement in construction
performance can represent a 25 increase in GDP (McGeorge amp Palmer 2002) Therefore there is
no doubt that improving productivity in the building industry will contribute positively to the general
economy
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The UK has a problem with productivity and the construction sector has poorer productivity
growth rates than any other Simply put productivity is the amount of stuff (whether goods or
services) that is produced by a person in an amount of time UK productivity is lower than it was in
2008 and the construction industry has not seen any significant growth in productivity in the last 20
years (Figure 22)
Figure 2 2 - UK productivity status (Office for National Statistics -ONS)
Not all the regions are struggling at the same rate and the reasons which will be discused
furthermore can be the insterest of regulators to support innovations and new solutions which can
improve the productivity in construction industry(Figure 23)
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS)
The result is that between 70 and 90 of projects exceed the original planned cost and that
the overrun commonly varies between 50 and 100 of budget Construction also suffers from 57
of effort on non-value-added activities compared with 26 within manufacturing (Figure 24)
These productivity rates had experienced severalrises and downs in some periods which is
because of increase of demandas of housing that results a boost in construction industry in order to
provide the needs
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Figure 2 4 - Value added comparison among industries (ennovacom)
Reasons of poor productivity
There are numbers of reasons for this poor performance The industry is extensively
regulated very dependent on public-sector demand and highly cyclical Informality and sometimes
corruption distort the market Moreover poor project management and execution insufficient skills
inadequate design processes and underinvestment in skills development RampD and innovation can
affect the productivity indirectly by decreasing the feasibility and value of the activities and add extra
costs on the project
Another key factor that causes a disruption among construction players which reduces the
average productivity rate is the lack of harmony in productivity between the players In other words
The sector divides mainly in two large-scale players involved in heavy construction such as civil and
industrial work and large-scale housing and a large number of firms engaged in fragmented
specialized trades such as mechanical electrical and plumbing work that act as subcontractors or
work on smaller projects like refurbishing single-family housing The first group manages to have 20
to 40 percent higher productivity than the second However even in the more productive heavy
construction sector there are endemic-potentially structural-challenges in meeting cost and schedule
commitments on megaprojects and players routinely subcontract specialized trades (McKinsey amp
Company 2019) (Figure 26)
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
7 | P a g e
Figure 2 6 - Fragmentations between construction industry players and their various productivity rates (McKinsey 2019)
Solutions for improvement
Nowadays there are solutions which are being used in construction world such reshaping the
regulation rewiring the contractual framework to reshape industry dynamics rethink design and
engineering processes improve procurement and supply-chain management improve on-site
execution infuse digital technology new materials and advanced automation and reskill the
workforce Each region based on their capabilities potential and Infrastructures would take a decision
which ways can be applied to increase the productivity in construction projects in a short or long
period
bull Redefine regulation Actions include streamlining permitting and approvals processes as
Australia has done reducing informality and corruption and encouraging transparency on cost
and performance as the International Construction Measurement Standards project does Many
governments allocate grants for innovation and training Germanyrsquos Federal Ministry of Transport
and Digital Infrastructure (formerly the Federal Ministry of Transport Building and Urban
Development) for instance supports RampD through studies in building materials Best practice
regulation would include moving toward outcome-based more standardized building codes and
consolidating land to promote scale Examples include Singaporersquos move to allow cross-laminated
timber (CLT) for high-rise structures and Japanrsquos promotion of scale through land pooling
bull Re-arrange the contractual framework Establishing a ldquosingle source of truthrdquo on projects for
monitoring progress early potentially supported by collaborative technology helps to minimize
misalignments and enable joint corrective action The data already exist to fundamentally
improve the accuracy of cost and schedule estimates Where players continue to use traditional
contracts they should introduce incentives that significantly improve performance and alignment
not at a trade or package level but at the project-outcome level To move toward best practices
appropriate alternative contracting models such as integrated project delivery (IPD) help build
long-term collaborative relationships Relational contracts will need to become more prevalent
than transactional contracts Sufficient investments in up-front planning incorporating all partiesrsquo
input have been shown to raise productivity substantially Smart Contracts are another example
of these solutions which during recent years is being identified by the major players A smart
contract is a computer program or a transaction protocol respectively which is intended to
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
8 | P a g e
automatically execute control or document respectively legally relevant events and actions
according to the terms of a contract of an agreement or of a negotiation The objectives of smart
contracts are the reduction of need in trusted intermediators arbitrations and enforcement costs
fraud losses as well as the reduction of malicious and accidental exceptions (Tapscott Don
Tapscott Alex amp Savelyev Alexander 2016)
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom)
bull Off-site production shift The biggest impact on productivity would come from moving toward
thinking about construction as a production system where possible encouraging off-site
manufacture minimizing on-site construction through the extensive use of pre-cast
technology assembling panels in factories and then finishing units onsite
bull Improve on-site execution There are four key approaches that are well known in the industry
but have not been universally adopted First is the introduction of a rigorous planning process
the Last Plannerreg System (LPS) is a useful tool to ensure that key activities are achieved on
time and on budget The use of integrated planning tools on a large-scale oil and gas project
for instance achieved a 70 percent increase in the projectrsquos productivity Second is reshaping
the relationship and interactions between owners and contractors and key performance
indicators (KPIs) being agreed on and used at regular performance meetings at which on-site
issues are resolved Complementing commonly used KPIs with additional forward-looking plan
conformance metrics to identify and subsequently reduce variance is critical Third is
improving the mobilization for new projects by ensuring that all pre-work (for instance
obtaining approvals and developing project milestones) has been completed prior to starting
onsite Finally there is a need for careful planning and coordination of different disciplines
on-site along with the application of lean principles to reduce waste and variability On-site
productivity can be increased by as much as 50 percent by implementing a cloud-based
control tower that rapidly assembles accurate data in near real time that is both backward-
looking and predictive (for example using plan conformance and other variability and
inventory metrics)
bull Introduce digital technology advanced automation Companies can start by making 3D
building information modelling (BIM) universal within the company alongside use of digital
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
9 | P a g e
collaboration tools drones and unmanned aerial vehicles for scanning monitoring and
mapping They can put themselves at the cutting edge by using platforms such as 5D BIM to
establish transparency in design costing and progress visualization (Figure 28)
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom)
Advanced analytics enabled by the Internet of Things to improve on-site monitoring of
materials labour and equipment productivity and digital collaboration and mobility tools (such as
construction management apps loaded on mobile devices) to better track progress and collaborate in
real time (Figure 29)
Figure 2 9 - Digital construction organization (wwwbimcommunitycom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Advanced automated equipment and tools such as bricklaying and tiling robots can accelerate
on-site execution The field of digital fabrication (dfab) is quite broad and has many applications Dfab
techniques are based on the combination of computational design methods and automated
construction processes which are typically categorized as subtractive formative or additive
(Kolarevic 2003) The use of subtractive and formative digital fabrication is becoming mainstream in
the prefabrication (off-site) of building parts (eg by using laser cutting CNC milling etc)
In recent years additive fabrication processes especially 3D printing have experienced a
rapid development in many industries As interest in additive fabrication grows research into large-
scale processes begins to reveal potential applications in construction (Labonnote et al 2016)
Existing additive dfab technologies can be classified in two big clusters on-site and off-site
construction technologies On the one hand on-site digital fabrication aims to bring additive
fabrication processes on construction sites
Sousa et al (2016) classified on-site technologies in three main categories large scale robotic
structures mobile robotic arms and flying robotic vehicles A well-known example from first category
is Contour Crafting a robotic structure for 3D printing large-scale construction developed at the
University of Southern California (Khoshnevis 2004)
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom)
bull Reskill the workforce Change in the construction sector cannot be achieved without
investment in retooling a workforce that is aging and changing its makeup through migration
Construction firms and workers need to continuously reskill and train to use the latest
equipment and digital tools In the mix should be apprenticeship programs such as the one
run by Siemens in the United Kingdom training frontline workers in core skills that are
currently underdeveloped and increasing stability in the workforce by breaking seasonality
and cyclicality
Brief on modular construction
History of modular construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
11 | P a g e
bull 1800s
In 1830 he first documented prefabricated home was created by London carpenter John
Manning for his son who was moving from England to Australia Manning built a prefabricated house
in pieces then shipped it to the Land Down Under for easy assembly In 1840 Modular construction
made its way to the United States in response to the housing needs of the California Gold Rush The
Crystal Palace was built for Britains Great Exhibition and remains one of the most famous examples
of early modular construction in 1851 Designed in less than two weeks it utilized light and
inexpensive materials such as iron wood and glass it was constructed in only a few months
Afterward the palace was dismantled moved and rebuilt at another location
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom)
bull 1900s
Augustine Taylor a builder in Chicago devised the balloon-frame method (Figure 212)
enabling walls to be built offsite then transported to the intended construction site for speedy
assembly The rise of catalogue houses happened Between 1908 and 1940 when Sears Roebuck and
Co sold more than 500000 prefab homes through its catalogue straight to consumers At the time
these houses cost less than two-thirds of conventionally built homes and many still exist throughout
the United States
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull WWII Housing Boom
Prefab structures continued into World War Two to meet the growing demand for mass
accommodations for military personnel So-called Quonset Huts or Nissen Huts in the UK
comprised of corrugated steel were introduced for domestic military and institutional uses
When soldiers began returning home in the United States there was a need for rapid
construction for new homes to accommodate these expanding families Once again modular
construction serviced those needs because of its efficiency reduced costs and quick construction
Today many of those units are still in use
bull Prefab in Post-war Europe
The situation in Europe was more difficult although millions of people had no place to live on
the Old Continent due to the destruction of the Second World War people were unwilling to accept
prefabricated construction In Germany which had not only lost 25 percent of its entire housing stock
to bombing but also had to integrate 12 million refugees from former German territories in Eastern
Europe one form of prefabricated housing was used extensively the Nissen Hut (similar to the
Quonset hut) An attempt was also made in post-war France to combat housing shortages with the
help of prefabricated houses In 1944 Jean Prouveacute was already commissioned by the Ministry of
Reconstruction and Urban Planning to build 800 houses as emergency shelters that could be easily
disassembled However only 400 of these Maisons agraveportique which were equipped with an axial
steel frame were ever erected Prouveacutes Alba houses developed for the Abbey Pierres homeless
organization in 1956 were also not a success (Peter Goumlssel Arnt Cobbers Oliver Jahn 2012
architectureweekcom)
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8 meters (modulartch)
bull The Pre-fabulous 60s
The 1960s were a period of social transition in which attitudes towards prefabricated housing
also changed During this era which was marked by space travel the moon landing and even childrens
books that predicted weekend trips to distant galaxies prefabricated construction was discovered both
as a form of artistic expression and as a technical means of creating houses to provide a basis for new
lifestyles which seemed to be imminent in a society characterized by an extremely optimistic view of
progress
These approaches supported the idea of creating megastructures out of residential capsules
the architect Moshe Safdie who was only 24 at the time presented his megastructure Habitat 67 at
the Expo 67 in Montreal 158 housing units consisting of 354 concrete modules assembled as a
conglomerate
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The British architectural group Archigram developed building structures made of residential
capsules as an architectural Utopia which could be expanded at will and joined to form entire cities
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau)
bull Eco-conscious 70s
In 1972 the Japanese architect Kisho Kurokawa built the Nakagin Capsule Tower in Tokyo
housing cells were layered around a prefabricated concrete core to form a fourteen-story residential
tower(Figure 215) The idea of residential capsule megastructures was repeatedly revived as in Zvi
Heckers Ramot housing development in Jerusalem in 1974
The ecology movement of the 1970s brought an end to this euphoria regarding technological
progress and futuristic architectural dreams Now highly modern building materials that did not seem
to be in harmony with a return to nature such as plastic or aluminium fell into disrepute A new
perspective of view replaced as a priority to choose the material types which have the minimum
relation with non-renewable resources
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
bull 90s
This was further exacerbated by the fact that prefabricated elements had often been used to
build high-density housing which was now generally viewed negatively Hence prefabricated building
now came to be associated with the aesthetic and social failure of deindividualized megalomaniac
prefabricated slab housing blocks clustered on the periphery of large cities Thus the acceptance of
the prefabricated house in large parts of Europe remained low up until the 1990s
Prefabricated construction only gradually began to again emancipate itself from a homespun
cheap mass-produced image during the 1990s This is mainly due to the use of computer-operated
programs in the design and production processes The prefabricated housing industry now stands at
a juncture reminiscent of the dynamism of the 1920s and 1930s
bull Modern days
For many years now companies like Muji in Japan or BoKlok in Scandinavia and more recently
also in Poland and England have been supplying prefabricated houses in large numbers In Sweden
alone with only nine million inhabitants 14000 units are sold every year Muji offers models designed
by Kengo Kuma and Kazuhiko Namba that are as simple as they are elegant and far more interesting
than the building-kit houses offered by the multinational concerns Mitsubishi Toyota and Panasonic
(deluxemodularcom 2019)
Countries around the world have enlisted prefab and modular construction methods for
decades For example an estimate of all detached homes that are prefabricated in each country
shows a potential for growth off 84 in Sweden 5 in the United States 9 in Germany 20 in the
Netherlands and 28 in Japan
Today prefabrication and modularization are utilized in the construction of hotels apartment
buildings offices hospitals and schools in every major US city Here is a rundown of the percentage
per industry of prefabricated structures that use some form of modular construction
(deluxemodularcom 2019)
bull 49 of healthcare facilities
bull 42 of college buildings and dorms
bull And 42 of manufacturing buildings
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Types of modular product
Module architectural types
The products can be categorized by its functions dimensions material or type of its operation
etc Here they will be introduced by their general characteristics
bull Bathroom pods
Bathroom pods are commonly used in the construction of most hotels and apartment
buildings these days and becoming used more for residential housing The main drivers for choosing
a modular pod method are
o The cost savings that can be made by building repeated designs in a factory
environment
o Higher quality finish
o Rapid installation
o No trades on site
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom)
Pod Construction Process can be various but the most common steps can be as below
(httpswwwhowickltdcom)
Once the bathroom specification has been finalized and the design completed the
machine files are issued and the framing can be produced
The frames are rolled out of the machine ready for assembly
The panels are assembled
The panels are then fitted with the internal boarding and finished with tiles or a
waterproof lining
The walls floor and roof are joined to create the room structure and the joints sealed
The fixtures and fittings can then be installed including
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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o Bath or shower
o Toilets
o Basins
o Lights
o Mirrors
o Cabinets
The plumbing and electrical components are connected
The pods are then subjected to an electrical test and a pressure test to ensure there
are no leaks (Figure 217)
The pods are then sealed to prevent access ready for transportation
Once on site the pods are slid into position and connected to the power and water services
This process greatly reduces the build time as there are no requirements for trades on the site As the
pods are sealed until the building is completed there are reduced chances of them being damaged
during the building construction phase
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom)
bull Kitchen pods
These pods are less common but are also becoming more frequently used All the appliances
and electrics can be fitted in the factory removing the need for work on site Kitchen pods are ideal
for renovating older or industrial buildings as all the electrical services for the building can be
integrated into the pod From student accommodation to residential flats modular kitchen pods are
suitable for a variety of different sectors and uses and because they are designed bespoke to each
clientrsquos exact specifications they can be anything from a fully fitted kitchen to a small kitchenette
Each modular unit is completely customisable from the worktops to the splashbacks and integrated
white goods
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Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom)
bull Volumetric and modular rooms
Volumetric and modular rooms are becoming widely used for buildings that have a repetitive
nature Common structures include
bull Hotels
bull Apartments
bull Student accommodation
bull Schools
bull Hospitals
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The benefits of being able to manufacture the complete unit in the factory (including the
bathrooms and fitting of furniture) are
o No weather delays
o Superior finish quality
o All the electrical and plumbing works are done in a controlled atmosphere
o The rooms are sealed before moving to site restricting unauthorized access
Modular rooms production process can be explained as below
Once the building design has been completed and the individual modules specified the
framing components can be made on a just in time basis for site delivery
A typical assembly process would consist of
The floor cassette is rolled and the flooring boards are attached along with the
required insulation and services
The wall and ceiling frames are assembled
The internal lining is fitted and painted
The wall frames are then attached to the floor cassette (Figure 220)
Figure 2 20 - Production steps of floor cassette to walls and their attachment together (wwwhowickltdcom)
The ceiling frames are then fitted
The bathroom can then be fitted and plumbed as well as the electrical fittings and
wiring
The wall and ceiling insulation is added to the frame
The fit-out can then be completed to the desired specification
A hotel module for example would feature carpets bed bedside furniture desk
wardrobe TV system air-conditioning (either vents from main system or stand-alone
unit) bathroom fittings and fixtures
Once completed the electrics are checked and the plumbing is pressure tested
A protective cover is then added for transport and the unit is delivered to site
On-site the units are craned into position and joined
The services are connected
The building is then roofed and clad to the required specification In some cases the cladding
can be fitted during the module assembly further reducing the on-site work
bull Modular Trailers
Outside of modular homes modular trailers are probably the type of modular building that
people are most familiar with These buildings have a lot of applications and are often used as a
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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temporary space solution These trailers can be relocated for several times and are well-equipped as
well Temporary pre-semester school classes and temporary offices can be two examples of these
trailers uses
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom)
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom)
bull Containers
When looking at modular containers they are structures that are typically used to contain a
shiprsquos cargo When Shipping containers were originally created they were designed with modularity
in mind They were required to withstand all kinds of abuse as they journey through some of the
worldrsquos harshest climates From salt water to freezing temperatures a shipping container is meant to
handle the worst of the worst while protecting some of the worldrsquos most precious cargo Comprised
of Corten steel it is in a shipping containers DNA to protect itself from any corrosion or rust and when
they fall off the ship they can take up to a week to sink With more boxes being imported than
exported we have an opportunity to reuse something that is desperately looking for a new home
There has been a shift recently where after these buildings serve their purpose as shipping containers
they are reused fitted with windows doors HVAC units etc And made into an office environment
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The biggest benefit of these containers is they are cheap very portable and easy to install on site
However since most of the time these buildings are retrofitted and remodelled into modular
buildings they usually do not have a lot of flexibility in layout or their dimensions
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom)
Shipping containers act as the exoskeleton of each module The original structure will frame
the HVAC wiring lighting plumbing appliances and wall finish materials Because containers were
built to be durable and mobile they can be transported by train tractor-trailer boat or in some cases
a powerful pickup truck Forklift pockets and corner castings allow the containers to be moved smaller
distances by crane and forklift Shipping containers empower you to move your modular structures
without sacrificing the structural integrity or damaging the modulersquos contents
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull Office Complexes
Office complexes will take several office modules and combine them to assemble a much
larger fully functioning office building Just like all modular construction these modules are
fabricated in a manufacturing environment except when these projects reach the job site they
function more similarly to a full-fledged construction site Generally the module will need a crane to
lift the section from the ground and place it in the correct spot to assemble the building Next the
workers will go through that module and do all things necessary to attach and hook up the piece
Then the next piece is put in place and these steps are repeated and again until the building is
finished
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom)
bull Modular enclosures
For instance one of the major electric utilities in the Northeast using Modular Construction is
Wunderlich Malec Integrated Control Enclosures since 2001 A standard 16times50times11-foot enclosure
with twenty (20) protective relay and control cabinets marshalling cabinets HVAC fire and security
completely installed wired and tested at the factory prior to shipment
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-Malec (wmengcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Module structure types
Modular structure types can be categorized by their materials or structural formation
o Steel Modules
bull 4-sided modules
In this form of construction modules are manufactured with four closed sides to create
cellular type spaces designed to transfer the combined vertical load of the modules above and in-
plane loads (due to wind action) through their longitudinal walls The cellular space provided is limited
by the transportation and installation requirements Depending on location and exposure to wind
action the height of buildings in fully modular construction is in the range of 6 to 10 storeys Modules
are manufactured from a series of 2D panels beginning with the floor cassette to which the four wall
panels and ceiling panel are attached generally by screws The walls transfer vertical loads and
therefore the longitudinal walls of the upper module are designed to sit on the walls of the module
below
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo)
It consists of a modular structure of high strength galvanized steel which is also used as the
basis for building closure Steel physical properties make it one of the most versatile materials for
construction since it is
ELASTIC Steel does not break as it has a great strength and elasticity It is easily workable and it has
a great advantage over traditional construction
RECYCLABLE Steel is 100 recyclable
DURABLE With zinc application it can become galvanized steel which has extraordinary durability
properties
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Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo)
bull Partially open-sided modules
4 sided modules can be designed with partially open sides by the introduction of corner and
intermediate posts and by using a stiff continuous edge beam in the floor cassette The maximum
width of opening is limited by the bending resistance and stiffness of the edge member in the floor
cassette Additional intermediate posts are usually square hollow sections (SHS) so that they can fit
within the wall width
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull Open sided (corner-supported) modules
Modules may be designed to provide fully open sides by transfer of loads through the
longitudinal edge beams to the corner posts The framework of the module is often in the form of hot
rolled steel members such as Square Hollow Section (SHS) columns and Parallel Flange Channel (PFC)
edge beams that are bolted together
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported module
(wwwsteelconstructioninfo)
bull Modules supported by a primary structure
Modular units may be designed to be supported by a primary structure at a podium or
platform level In this case the supporting columns are positioned at a multiple of the width of the
modules (normally 2 or 3 modules) The beams are designed to support the combined loads from the
modules above (normally a maximum of 46 storeys) The supporting structure is designed
conventionally as a steel framework with beams and columns that align with multiples of the module
width and provides open plan space at ground floor and below ground levels This form of construction
is very suitable for mixed retail commercial and residential developments especially for residential
units above commercial areas or car parking etc particularly in urban projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the lower levels
(wwwsteelconstructioninfo)
o Wood structure
Back in the days of the very first modular buildings wood was the modular construction
material of choice and nowadays it overwhelmingly remains the most used for these projects due
to its abundance and cheaper initial costs Wood-framed modular buildings however have several
notable limitations that might give a property developer pause and may even prove more costly in the
long-term repairs
Wood often lacks the strength necessary to support large building projects especially those
of multiple stories Due to this weakness wood-framed buildings are typically no taller than a few
stories a considerable limitation for someone looking to build a hotel or apartment building as
examples
Wood is flammable and vulnerable to fire which could severely damage the structural
integrity of the building requiring replacement or even worse leading to a total collapse
Wood tends to warp over time resulting in a lower quality building in the years after
completion Combined with its susceptibility to pests and mold selecting wood for a modular
structure may prove to be the more expensive choice in the long term considering repair costsmdasheven
despite initial savings
Wood is among the most wasted materials used in modern construction On average 20 of
construction lumber typically ends up in landfills leaving a larger environmental footprint than other
alternatives (httpswwwdeluxemodularcom)
Considering all those negative points mentioned earlier there are numbers of regions that
still are oriented to wooden structures as this type of housing is part of culture of the society because
of traditional architecture etc therefore typical clients prefer to build the type of accommodation
that they trusted for many years as it became the main demand of market Accessible local resources
availability of necessary knowledge for construction and compatibility of labour forces with this
method are other reasons to be chosen over the other alternatives
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other metals
(vanguardmodularcom)
o Concrete modules
Precast concrete is a well-established and efficient manufacturing industry and products
range from hollow-core slabs to beams and columns in structural frames Concrete modules can be
manufactured in two ways either from precast 2D wall floor and ceiling panels or as 3D modular
units which are generally cast with an open base Concrete modules are often used in high-security
applications as they are extremely resistant to damage
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma Beton)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
27 | P a g e
Types of modular buildings based on operation period
bull Relocatable Buildings (RB)
Relocatable modular buildings are designed to be reused or repurposed multiple times and
transported to different sites Relocatable Building as defined in the 2015 International Existing
Building Code a partially or completely assembled building constructed and designed to be reused
multiple times and transported to different building sites
bull Permanent Modular Construction (PMC)
PMC is an innovative sustainable construction delivery method utilizing offsite lean
manufacturing techniques to prefabricate single or multi-story whole building solutions in deliverable
module sections PMC buildings are manufactured in a safe controlled setting and can be constructed
of wood steel or concrete PMC modules can be integrated into site-built projects or stand alone as
a turnkey solution and can be delivered with MEP fixtures and interior finishes in less time with less
waste and higher quality control compared to projects utilizing only traditional site construction
Common uses of modular buildings in the market
o Education
Relocatable buildings have become a critical factor in managing student demographics and
increasing enrolments Relocatable classrooms are also ideal for swing space during new construction
or renovation Convenient flexible cost-effective temporary buildings can be delivered and
operational in as little as 24-hours These classrooms are measured for quality and code compliance
by state or third-party agencies through routine and random inspections testing and certification
services Customers may choose single classrooms or arrange multiple buildings in clusters to create
a campus feel MBI members supply steps decks ramps and even furniture Members also offer
lease purchase and lease-to-purchase financing for a variety of public and private school needs
These classrooms are sometimes referred to as temporary portable or mobile classrooms
o Construction-Site
Relocatable buildings have their roots in construction site trailers where speed temporary
space and relocate-ability are important Used as standard field offices construction site and in-plant
buildings are available for immediate delivery Standard construction is wood but steel units are
available to meet non-combustible requirements In-plant buildings are available as single- or two-
story units for industrial environments with noise reducing insulation and are typically moveable by
forklift and include electrical and communications wiring heating air conditioning and even
plumbing
o Healthcare
Relocatable buildings for healthcare applications are designed and constructed to
uncompromising standards of quality A customerrsquos new clinic hospital extension laboratory
diagnostic centre MRI unit dentist office or other medical facility can be open for business and
serving communities in as little as a few days Is your interest in serving patients as quickly as possible
in the safest and aesthetically pleasing environments available These facilities offer quick quiet safe
and clean buildings with an unlimited choice of interior deacutecor and furniture and equipment leasing
o General Administrative and Sales Office
When production demands increase relocatable buildings can temporarily enlarge a current
facility without permanent alterations to the site Because the space is not permanent many
companies are able to expand without the budget approval process necessary for traditional capital
expenses Relocatable offices can be single- and multi-story buildings configured to include
independent offices conference rooms and large open spaces for cubicles or other partition systems
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
28 | P a g e
Large and small businesses as well as local and state governments are typical users of relocatable
office space
o CommercialRetail
Earlier occupancy means quicker return on investment For retail occupancies this can mean
significant cash flow advantages Standard floorplans are available for immediate delivery while
custom buildings are built to specifications in weeks not months Unique to the modular process is
concurrent construction site-work occurs while buildings are being put together in a quality-
controlled factory Typical retail applications include new home sales centers banks golf pro shops
automobile fleet ownerships college bookstores and concession stands If a clientrsquos emerging
business needs are short-term temporary space will accommodate their financial situation space
requirements and deadlines
o Security
Relocatable buildings can be custom built for a variety of access and control situations Toll
booths tickets sales offices guard stands and weigh stations are common applications One and two-
story wood and steel buildings have straight walls or walls that are tilted to improve views and reduce
glare
o EmergencyDisaster Relief
There is simply no other means of providing fast transitional shelter and basic community
needs following natural disasters than relocatable buildings Relocatable buildings can be quickly and
efficiently deployed for emergency shelter medical and educational needs or to accommodate relief
workers
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction report MBI 2019)
Construction phases
Modular construction is the process of manufacturing multiple building sections in a facility
for assembly at a remote building site The building sections called modules will fit together once
assembled on site with plumbing HVAC and electrical connections running throughout One of the
great advantages in the modular construction process is that many of the processes happen at the
same time which can cut the construction time in half There are six common steps to complete a
modular project Design amp Engineering Permits amp Approvals Site Development Plant Fabrication
Transportation and Installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
29 | P a g e
Figure 2 34 - Overlaps of phases in modular construction project
o Step 1 Design
The design phase of the modular building process creates a description of the building usually
represented by detailed plans and specifications A thorough customer consultation with a Palomar
project manager gathers the information required to develop the building plan Once this information
has been gathered the design team will produce the ideal modular building design to fit the customerrsquos
needs
o Step 2 Engineering
Each building design goes through the engineering department for an engineering review Like
site-built structures modular buildings are subject to a series of national state and local building
codes that ensure the building meets a set of standards for safety and performance State level
building codes can be superseded or augmented by local building code requirements and then must
confirm the design proposal meets all applicable building codes
o Step 3 Permits amp Approvals
A construction permit or building permit is a permit required in most jurisdictions for new
construction or major renovations Typical construction permits required can include
Site plan
Building permit
Mechanical permit
Plumbing permit
Concrete permit
Encroachment permit
Sign permit
Flood district development permit
The building owner is ultimately responsible for securing building permits for work on their
property In practice most building owners appoint the general contractor as an authorized
representative so the contractor can obtain the required permits The building owner is advised to
confirm that the general contractor has secured the proper building permits for their project Failure
to obtain the proper permits can result in significant fines penalties and even demolition of
unauthorized construction
o Step 4 Site Development
One of the advantages inherent in modular construction is that the site development and
building foundation are prepared while the modules are being fabricated at the manufacturing facility
and transported to the job site The site development and building construction processes happen
Permits
Design amp Engineering
Site Development
Plant Fabrication
TransportationOn-site installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
30 | P a g e
concurrently instead of sequentially like site-built construction Projects are developed on a variety of
geographic settings typical site development includes
Surveying
Demolition
Excavation
Grading
Site drainage
Foundation construction
Utility installation
There are two primary modular building foundation classifications on-grade and raised or full
foundation An on-grade foundation is generally for permanent installations and is more expensive A
full foundation can be used for temporary or permanent structures it is less expensive to install and
it is more cost effective to relocate the building later while causing minimal site disturbance
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom)
bull Step 5 Plant Fabrication
There are two scenarios for steel modular constructors There are few numbers of off-site
plant which built their own steel frames inside the plant because of high initial budget and it is
common that it would be cheaper to order the frames from another supplier and transfer to the
factory to assembly with other parts The steel frame is then loaded on the main factory production
line where the sub-floor is insulated and floor decking is assembled atop the steel frame As the
module moves down the production line framed wall sections are fabricated insulated and hoisted
in place The truss roof assembly is built in components at ground level before it is hoisted into place
The module proceeds down the line where mechanical electrical and plumbing services are installed
while the last of the insulation goes into place Interior finishes like drywall painting and flooring are
applied while doors and windows are installed
On the last stop of the production line the exterior finish and trim are applied before the
module is prepared for transportation
During construction at the manufacturing facility a third-party inspection agency is present to
ensure the modules are built in compliance with building code
bull Step 6 Transportation
The fabricated modules are shipped over the road by carriers that specialize in modular
building transportation In most US jurisdictions building shipping limitations are 16rsquo in width and
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
31 | P a g e
between 70rsquo amp 90rsquo in length per module Permissible Maximum Dimensions of Lorries in Europe and
UK for Lorry or Trailer are 4m in height 255m in width and 12m in length (International
Transportation forum)
bull Step 7 Installation
A general contractor often one specializing in modular construction will install the modules
complete any on site finish out and make the final utility connections
The choice of building foundation determines how the building will be installed Permanent
semi-permanent and on grade foundations will require the modules to be set with a crane Raised
foundations typically used for temporary buildings allow the modules to be set in place through
simple mechanical methods
With the modules in place final finish out of the interior and exterior proceeds Finish out can
include electrical and mechanical system connection between modules stairs wheelchair ramps
skirting exterior siding trim and utility connections
Literature review on possible advantages
Modular construction comes with advantages which motivates investors and innovative
constructors to apply this method on their future projects Here these benefits are being classified in
various sections such as schedule economic environmental health and safety and social-laboral
advantages
Scheduling benefits
While on-site constructors are complaining about the slow progression of construction
activities and delays on project deliveries the struggle is still to be continued to find new methods to
improve productivity and progression speed while maintaining the quality at a reasonable level
whether if its achievable or not On the other side modular construction because of numbers of
reasons is making a significant boost in term of time management in many phases As it can be seen
in figure 236 McKinsey amp Company report explains that approximately between 20 - 50
scheduling improvement can be achieved in comparison with traditional on-site construction
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method (McKinsey amp Company
2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
32 | P a g e
To be more specific literature reviews identified numbers of benefits in most of the
constructive activities from design to on-site installation As the table 22 illustrates off-site
manufacturing brings most of the time saving to the project by better coordination precise quality
management and not being affected by the on-site bad conditions Table 2 2 - Possible benefits in projects scheduling
In addition design can the ability to be applied in multiple projects instead of just one which
accelerates the project schedule significantly Various overlaps in modular construction can save lots
of time in projects such as site preparations off-site manufacturing and on-site installation with each
other
The acceleration in design process which would be ideal for schedule-critical projects (for
instance emergency accommodation for people who are affected by natural causes) also Long-lead
items can be stocked Fabrication can start and finish earlier in this case In the real state point of view
in the design phase there is one huge benefit which will be so handy when nearly ldquoshovel-readyrdquo
design documentation is needed for clients and site selectors (wwwmcminnvillebusinesscom)
The simplicity precision and clarity of the design plans in modular projects can increase the
possibility of using advanced software such as BIM which reduce the period time of designing phase
significantly With the increasing the possibility of integration of BIM in construction project
incorporating modular building technologies into project becomes more developed and
manufacturing and construction process could be streamlined (Na Lu and Thomas Korman 2010)
About 90 percent of the build activity takes place indoors which means the building process
is nearly guaranteed to stay on schedule That predictability and reliability enable you to count on
timely project completion If a skilled modular crew only spends half the time building your structure
than a site-built crew would your labour cost also gets cut in half
Because of stability of production location there are numbers of advanced technologies
which are being used in other industries production lines that can be used in these off-site facilities in
order to improve the productivity and reduce the timeline of the activities
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
33 | P a g e
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom)
The nature and outdoor construction have always mutual effects on each other mostly in a
disfavour way Site conditions often cause negative impacts on the activities which lead delays quality
insurances or stop them because of safety matters In result the project schedule can be changed and
most of the times unpredictive delays will take place in the timelines In addition there are sites which
the possibility of on-site construction for most of the year is almost zero percent or if exists would be
limited because of life risks for workforce A reasonable solution for these cases is off-site construction
which in most of them reduce the nature effects Thus factory-based production can make a
revolutionary impact on the project scheduling In modular method 60-90 of the construction work
is completed in a closed factory environment and this mitigates the impact of unfavourable weather
(FLORI MURESAN on ny-engineerscom)
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
34 | P a g e
Machinery equipment can take place in mentioned phase instead of human labour which can
boost the productivity quality as well as the time reduction Robotic assembly is one the efficient
examples of this technology One of the very first EU projects carried out in the Robotics Lab
(httproboticslabuc3mes) located at the Carlos III University named FutureHome-IF7 project The
done research was focused in the robotization and industrialisation of the final stage of the
construction process by mean of modular construction (Martinez 2008)
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes)
Economic benefits
Economic advantages can always attract investors to develop innovations Since in a project
time and cost have a direct and mutual relation with each other most of the benefits which were
mentioned earlier in the schedule section can also make positive impact in projectrsquos economy In
some cases these benefits equal to the initial costs which will be discussed later in challenges As it
was mentioned earlier the design plans can be repeated multiple times in projects because of
similarity of requirements that can save design costs in future budgets
Modular building because of their standardization and classification in design phase can be
more compatible with advanced such as BIM (building information modelling) BIM technology in its
5D phase does cost estimating material quantifications and pricing to be automatically generated
and modified while changes are applied for each building module (Na Lu and Thomas Korman 2010)
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
35 | P a g e
Foundations do not have complexity in modular buildings because of weight of the modules
which have to be manufactured lightly in order to be transported simpler to the location
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk)
Also because of the high quality and precise off-site execution there are fewer reworks in
modular products which can save costs in projects Off-site manufacturing provides more economic
benefits such as reduction of salary wages due to a smaller number of workers and more specialized
ones and adding values to each hour of work by increasing productivity to the activities
Moreover massive orders of Materials to the supplier can bring more quality to the material
multiple discounts on each offer and add more stability in prices of material in instable markets Table 2 3 - Economic benefits in modular method
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
36 | P a g e
Environmental Benefits
A highlight among the modular constructionrsquos benefits is in the environmental point of view
Since the modular buildings are friendly with environment many clients are willing to change their
method to this ecological approach in order to make their projects more sustainable and promote
their product in the market as an innovative constructor in the industry such as ldquoGrupo Consentinordquo
which not only builds modules that are available to use solar panels as energy supplier but recycle
many structural and non-structural elements and reuse them in another projects Waste management
can be applied simply in modular construction by reduction in waste during off-site production recycle
and reuses in elements in several projects use of automation can secure waste reduction at a high
rate It has been proven that modular construction can reduce waste by up to 90 thanks to off-site
construction (JAHNAVI SAJIP ny-engineerscom)
Agostinho Mendonccedila in 2018 did a research about reuse in construction industry which
shows a great improvement in terms of sustainability During 2022 FIFA World Cup in Qatar football
fans will have the opportunity to enjoy the stunning views of Doharsquos skyscrapers and be marvelled at
the unique Ras Abu Abod Stadium Its design concept results in a good cost-efficient arena with an
elegant curved square form
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images)
This innovative stadium will also allow it to be completely disassembled after the World Cup
Precisely many elements of the arena including all 40000 seats the containers and even the roof
will be reused providing valuable infrastructures to sports and non-sports projects elsewhere
Moreover off-site manufacturing can reduce emissions much more than conventional
method In 2009 Al-Hussein et al focused on the construction phase of modular and conventional
buildings and compared their CO2 equivalent emissions They analysed a 42-suite multi-family four-
story residential modular building located in Alberta Canada All the construction activities needed
for this building and a similar conventional building such as material delivery transportation
workforce trips equipment usage and winter heating were identified separately Therefore CO2
emissions from each of these activities were quantified The authorsrsquo analyses showed that modular
processes led to a 43 reduction in CO2 emissions compared to on-site processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
37 | P a g e
Table 2 4 - Environmental Benefits
While the on-site construction disturbs the sitersquos neighbourhood with noise dust congestion
and waste modular construction performs better by providing minimal project site disturbance
(Mohammad Kamali2016) Since most of the construction process takes place offsite there is less
impact on the project surroundings Modular construction reduces the number of vehicles and heavy
equipment required on site which translates into reduced pollution and less site disruption
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site (wwwcadoltocom)
Energy consumption in the occupancy phase of modular buildings dominates the other life
cycle phases This phase alone accounts for more than 70 and up to 98 of energy consumption and
consequent impacts over the life cycle of buildings while the contribution of the construction phase
is relatively small (M Kamali 2016) Sustainable material selection optimum modular factory
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
38 | P a g e
location and availability of labour which lead to less embodied energy consumption are effective
opportunities to reduce the life cycle energy consumption and the subsequent environmental
impacts In addition a smart design of insulation which is advanced in modular buildings can achieve
a high amount of energy use saving during the operation phase
Figure 2 44 - various layers of a module building unit including insulations (wwwsteelconstructioninfo)
Health and security benefits
When it comes to safety modular method can offer advantages for both phases (construction
and operation) to workers and future users Converting possibly dangerous on-site activities to an off-
site plant that there the supervision and control is much higher can reduce the accidents for the
workforces and the products It is obvious that the safety plan can be applied much more efficient in
a factory environment Not only is there a reduced risk of slips trips and falls ndash particularly as work
at height is reduced but there is also a reduction in onsite activity thus ensuring health and safety
always remains a top priority from start to finish
Furthermore if necessary factory operations can continue 247 with less risk of noise and
disruption to workers Work is also unaffected by the weather and other environmental delays which
could result in the project being turned around even quicker
On the other side during the operation phase safety can be improved for instance fire
protection can be designed by using multiple insulations and protectors inside the panels
One of the examples is Actavorsquos plan for Ensuring everyonersquos safety is at the heart of Actavo
what does and in line with this they have developed the HEART (Help Eliminate All Risks Today)
procedure Devised and implemented in the continuous effort to create an accident and incident-free
environment the HEART behavioural safety observation process sets the whole Actavo teamrsquos
expectation every injury is preventable so do not let any happen (Hannah Vickers b4edcom)
Modular construction generally achieves these requirements using fire-resistant plasterboard
conforming to BS EN 520 Alternative materials such as cement particle board and gypsum fibre board
may also be used in combination with plasterboard as the facing layer In residential construction
each dwelling usually forms a separate fire compartment All walls and floors that provide a separating
function between compartments require 60 minutes fire resistance In hotels and other residential
buildings each bedroom may form its own compartment (wwwsteelconstructioninfo)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
39 | P a g e
Figure 2 45 - Compartment floor at junction with external wall and compartment wall (wwwsteelconstructioninfo)
Social-Laboral benefits
Most of the mentioned benefits including economic scheduling environmental and safety
advantages have direct effect on social well-being as well Therefore they can also be named in this
section Future users can benefit from the quality of building energy savings etc which leads to
costumerrsquos satisfaction among the public Due to the shorter on-site schedule there are fewer
negative impacts on local businesses urban beauty image than conventional constructions Also
modular construction demands more skilled workforce and experts which can create more jobs for
these group of labour in the regions that struggle with high unemployment rates
In addition every industry needs to trust innovations in order to improve the science and help
the innovator to break limitations and explore new alternatives to solve problems Modular
construction as it was mentioned can be a great solution for the productivity problem in construction
industry and by applying these method it is possible to even find more solutions in the future which
can increase these rate more or solve other problems that nowadays are common among players of
construction industry Table 2 5 - Health and safety amp Social-Laboral advantages
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
40 | P a g e
Modular Construction role in COIVD-19 Pandemic
Recognizing the urgent need to create modular critical care units for rapidly growing numbers
of COVID-19 patients HGA Architects and Engineers partnered with Boldt Construction to design and
build a new system within a noticeably short timeframe ldquoThe initial idea was to provide rapid
response for hospitals and build a product with off-the-shelf readily available parts because we did
not know what the supply chain would be like Over the course of three weeks we went from concept
to full design and fabrication was underwayrdquo reports Ben Bruns executive vice president of Boldt
Construction in Appleton Wis (Rapid Response by Barbara Horwitz-Bennett 2020) The final product
was a prefabricated modular solution for assembling field hospitals capable of providing airborne
infection isolation rooms
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use inside convention
centres arenas and temporary structures Image courtesy of HGA and The Boldt Company (prismpubcom)
These Strategic Temporary Acuity-Adaptable Treatment (STAAT) units are isolation units with
enough clearance for safe bed transfers and accommodate equipment and a reclining chair These
multifunctional modules can be used as supplemental interior isolation rooms within an existing
system of care as a modular system connected to an existing hospitalrsquos infrastructure or as a self-
sufficient temporary hospital with its own infrastructure
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The Boldt Company
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
41 | P a g e
PCL Construction has come up with a similar solution in collaboration with Thor Plumbing and
Heating f-BLOK Architecture EH Price Industries and P4 Electrical Contractors Called ldquoQuaran-Tin
Podsrdquo the units are emergency response modular isolationcare rooms that provide temporary and
reusable emergency isolation for care and treatment of COVID-19 patients Each unit is self-contained
with built-in power heating and cooling as well as connections for medical gas oxygen and vacuum
Highly scalable and customizable the pod is continuously negatively pressurized and all the exhaust
is HEPA filtered Citizen Care Pod is a smart screening and testing pod that integrates intelligent
technology within a modular design to support a safe responsible recovery for governments
businesses and communities Customizable with the capabilities to enable full-on mobile COVID-19
testing in high-traffic environments the project will help in testing screening and eventually
vaccination on a mass scale (Christele Harrouk on archdailycom)
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction (archdailycom)
The Citizen Care Pod is a turnkey solution that accelerates recovery for businesses and public
institutions such as airports offices sports and entertainment complexes construction sites and
more by rebuilding staff and customer confidence that your organization is equipped to ensure their
safety
Unfortunately the COVID-19 pandemic is only intensifying the housing crisis Further
complicating the issue is the fact that a significant percentage of skilled labour workers will be retiring
within the next couple years which will significantly impact the construction industry As stated in
MBIrsquos ldquoThe US Construction Industry A National Crisis Loomingrdquo there are currently not enough
skilled workers to build all of the projects that need to be built in the same manner in which they have
been built in the past ldquoThere is no other choicerdquo advises Hardiman ldquoIt is now time for our
policymakers to start looking at alternative ways to build everything and we think that modular
construction should be a part of that solutionrdquo Along these lines the COVID-1 Response Page also
includes links to articles illustrating how MBI membersrsquo systems and facilities are currently being used
in housing infrastructure and COVID-19-related projects
Review on common challenges
Initial costs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
42 | P a g e
To start the modular construction method in an area there will be a significant investment
to establish a production plan and then designing team who must work alongside the execution
engineers parallelly in the design phase
factory cost Like any other industry modular construction demands a production line which
is an off-site plan with a supply chain based on 3D volumetric products First the off-site plan must be
designed based on the local requirements amount of demands availability of experts and labours and
budget that manufactures are willing to invest on this technology These factories are mostly
expensive to be build and the issue of production costs will always be a barrier to innovation in
modular construction because both the client and the architect will expect lower fabrication costs
However the art of every industrial innovative player is to study the economic pros and cons
of issued technology and then the industrial expert by doing couple trade-offs between the benefits
and disadvantages can make the decision whether to apply the new method or not Modular
construction is not an exception of this fact A local study can tell the investors if the approach would
be reasonable in all term and not only economic terms for the society or not Thus due to the
economic benefits that were mentioned earlier in numbers of regions which the labour salaries are
higher and the balance between transportation costs primary material access and costs experts
existence local market and their demand of real state and initial costs is more favourable modular
construction can be the best solution to apply On the other hand nowadays there are numbers of
region which the investors of industry are eager to use innovative method with higher costs that have
positive influence on environment and public health in which modular construction is more friendly
than the conventional method
Figure 2 49 -Balance between Initial costs and Economical benefits
First design costs and errors By changing the traditional construction products a change of
design is also demanded Modular design can be based by the production linersquos technologies the
budget of manufacturer and the final products quantity and quality In the earlier discussions about
design phase the complexity of 3D volumetric design had been mentioned and surely in the first
attempts would be expensive for the manufacturer However if the design could focus more on the
standardization of elements repetition in production line and consider integrate with modern design
software in order to provide more executive details and minimize the future errors and reworks the
rework cost can be eliminated and the design sample can be used for numbers of projects as a
catalogue with few changes Therefore by having these advantages the initial design cost can be
recovered soon and even make more benefit by the time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
43 | P a g e
Architectural challenges
One of the main group of experts who have argues about modular buildings are the
architectures who always suffer from limitations that this approach puts on their design process Most
of these challenges are mentioned below
bull Manufacturing technologies effect on the design One of the challenges which the manufacturers
can struggle is to consider a production line that be able to produce a wide range of product so
that there will be fewer limitations on the design phase This goal can often be impossible because
of the predicted budget of investors limited area of production plant and lack of technologies
Thus it is the architect who must be flexible with the production line and its boundaries
Moreover it is the art of the architect which can maintain a balance between ability of production
line and attractivity and innovation of the final product for the market and the industry
bull Transportation boundaries on architecture It is a fact that the transportation of modular
construction have puts limitations on the architectrsquos works The modules must obey the
obligations and regulations of the region that want to be transported in Therefore architects
must design modules which are transportable and minimize negative economic and timing effects
for the project In addition in the designing process environmental aspects which can be
happening during the transportation phase must be considered
bull Regional architecture specializations There are cases in which an off-site production plant ships
same model of modules for numbers of projects which are going to be assembled in variety of
regions with different climate cultural architecture and local construction regulations which can
surely have negative effects on the regionrsquos construction industry real estate market and cultural
architecture aspects For instance the harmony of the angel of sunlight and the windows
formation and dimensions in a residential building located in eastern region and western ones
which reduce or increase the sunlight absorption inside the building for the residents In this case
if the same form of modules will be transported and assembled without of any changes the
unsatisfaction of future users can be increased and in a result the demands can be reduce
significantly which could cause a failure for the real estate and construction industry of the region
In terms of architectural culture modular manufacturers must consider the traditional
architecture of the location in the designs in order to make sure that the harmony will be kept
among the present buildings and modular ones
bull Lack of knowledge about modular buildings among architects Manufacturers argue about the
lack of enough knowledge of architects about the modular fabrication process The third-party
inspections and approval process Transportation methods and its boundaries Onsite assembly
procedures The cross section of a modular structure which can reduce their understandings from
manufacturerrsquos demands of project and result a unsuitable design for the final products These
disagreements come with every innovation in civil engineering society which architect must follow
their lead most of the time The solution for this cause is to educate the architects by planning
workshops by the manufacturers or internships during a project so that architects can improve
their knowledge and gain actual experiences by observe and participating in real projects
bull Unfeasible on-site finishing Common architectural innovative designs focus a lot on finishing
works in order to gain attentions of buyer and improve attractiveness of buildings There are
different views about this subject Some manufacturers think that the finishing process must be
as simple as possible or minimize the schedule and costs on-site to benefit from the project On
the other hand architects believe that the modular buildings are not attractive enough because
of repetition in their design and try to focus on finishing process to make them desirable to the
market or improve the products in architectonic point of view
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
44 | P a g e
Transportation challenges
By transferring most of the construction activity to the off-site plant transportation plays a
vital role in the projects so that in case of poor logistic management can damage numbers of benefits
which were achieved in the factory plant
bull Dimensional and weight barriers based on type of transportation The type and technologies of
every modular constructorrsquos logistics can affect the project from the design phase to the on-site
assembly These effects can change the dimensions weight and structural features of the product
For instance modular structures transported on a flatback trailer will be limited in length width
and weight based on the physical capacity of the truck Components fit into shipping containers
are best suited for projects overseas because the structural integrity of the containers allows for
unorganized stacking However components will be limited by the interior dimensions of the
container in length width and height (Joseph M Schoenborn 2012)
bull Long distance transportation and lack of existence of local factory Off-site plants are not
available for every site location in numbers of states or even regions yet because of poor
development of these method in those regions Therefore in some cases the modules must
shipped even overseas to the site location to be assembled Long distance and its possible
difficulties during ground or marine transportation can bring extra costs for the project which
must be studied economically before the biding process
bull State regulations on structures dimensions and strategic issues Estate laws can always put
boundaries on construction industry and modular constructors are not an exception Every region
has its structural and transportation regulation which limits the final product In addition estate
approval during transportation phase can harm the projectrsquos scheduling program and put delays
on the arrivals or even occasional penalties which causes extra costs in the budget
bull Negative effects from environment on the modules during the transportation While the
modules are being transported to the site these products are in direct exposure to the
environment such as sunlight rain wind and other natural causes By the time possible damages
can be appeared in the modules which in some cases can be too critical that module need to be
repaired or replaced to be used On the other hand ground transportations can cause vibrations
on the trucks and its loads and the intensity of damage generally increases with the roughness of
the road surface which in some creates cracks or more critical damages on the structural element
installations or finishing The solution is to use To minimise transportation difficulties the vehicle
having vibration absorber can be used to minimise damage due to vibration and additional
precautions need to be considered for wider modules while low bed transport vehicles are
preferable for transporting taller modules (W Ferdows 2019) Moreover loading and offloading
processes must be carefully done by precise strategy and adequate equipment in order to avoid
the harms on the products
bull Transportable materials There are two terms which force modular constructors to use advanced
and high-quality materials transportation and design situations Transportation as it mentioned
earlier puts limitations on the final product and force the constructors to use material which have
less weight more against resistance road vibrations and endurance against sunlight and humidity
exposures In one word these materials must be part of a final product which can be
transportable Often these materials add costs on the project because they are more expensive
than the ones which have been used in conventional buildings All properties need to be
structurally sound in situ but units built using offsite construction methods also need to be
structurally sound whilst being raised and lowered throughout the transportation and assembly
stages of the process Key structural elements such as beams columns and potentially walls and
floors must be repeated in three-dimensional modules for transportation purposes This can
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
45 | P a g e
significantly increase material costs depending on the material choice and level of design
optimization (McKinsey amp Company 2019)
On the other hand numerous benefits which modular construction has in terms of material
such as less reworks discount on massive offers no exposure to natural causes and its off-site storage
and less waste during the production can assure the constructors that these challenges can overcome
the fact that modular buildings work better than conventional ones in a material criteria
Wrong perceptions among public and real estate market
Innovation without correct publicity brings wrong perception among people and markets
Also errors bad experiences of users and unprofessional works can change the mindsets quickly by
unsatisfying the users and in result investors During a period in past off-site accommodations were
mostly for temporary uses with low quality material and less functional features The demands of
permanent housing raised after a break such as world wars for those who lost their houses and
refugees that wanted to live abroad Therefore numbers of companies started to modify their off-site
products in order to have more lifetime and serviceability However there were constructors who
could not provide buildings with better functional services and the users became unsatisfied and lost
their trust in these products This wrong perception had been raised even until now that off-site
building such as modular ones will not serve a long lifetime and have low quality material incommode
and unattractive design and a poor functionality Obliviously bad perception of people will reduce the
demands and destroys the market as well
Today the industry recognizes the need for durable construction for even temporary uses
making it possible to move and re-use full buildings So a lack of knowledge among consumers as to
what is possible can prevent design innovation In order to overcome the stigma sometimes associated
with modular construction manufacturers attempt to offer a built product indistinguishable from one
built onsite Therefore the industry advertises a direct alternative to onsite construction In a
comparative analysis of the two processes time savings and worker safety stand out as the primary
advantages of modular construction over onsite construction The building manufacturing process
itself construction in a controlled environment with access to advanced technology is an evolution
of the art of building which is traditionally slow to evolve The modular building industry therefore
should advertise a different building product altogether featuring design innovation and ingenuity
executed through advanced building techniques (Joseph M Schoenborn 2012)
Moreover in order to raise the demands among the public who can be future users a range
of positive publicity about the environmental advantages such as less emission economic savings like
less energy bills cheaper and easier maintenance processes during the operation phase and faster
construction process which help them to be accommodate sooner can create a positive mindset
among the public In addition post-sell services from constructors such as better assurance policies
for buyers maintenance services and offering loans to customers who are in emergency
accommodation needs can change the market significantly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
46 | P a g e
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects (casasinhauscom)
Integration of advanced software
As it mentioned before modular construction can benefit from using innovative software in
their designing phase in order to be more precise on planning and provide detail for the production
line One of these software programs is BIM which can be used in design construction phase on-site
assemble and even operation phase However despite its advantages there will be some challenges
as well The greatest challenge of using BIM in construction project is the implementation process
itself regardless of the software capabilities Development of accurate BIM model requires extensive
resources and in-depth knowledge of construction methods and process Most small or medium firm
could not afford the special team and man hours to aligning BIM (Na Lu and Thomas Korman 2010)
Other than finance and organizational issues the project team has experienced legal challenges as
well The use of BIM technology encourages multi-disciplinary collaboration which contrasts to
defining responsibility to each party and then assigning liability issues among the parties In addition
using BIM models instead of traditional contract documents raises questions on insurance coverage
and confidentiality exposure Ownership and control of the model use and distribution of the model
and intellectual property rights are some of the issues that need to be addressed while BIM
implementation being adopted in construction industry
Redefining the contracts
Due to the changes over the responsibilities of every participants the amount of their
influence on projectrsquos activities and transferring most of the work to the off-site plant a new way to
contracting is needed in order to optimize the relationship between the owner designers and
manufacturers during all phases of the project Here are some of the common types of contracts which
are being used among modular building industry
bull Design-build The architect modular manufacturer and onsite general contractor are
hired as a team and assume the responsibilities of design and construction together DB contract can
be named one of most traditional types of contracts that would create an integration between all the
parties of a project Due to the design-build nature of modular construction a close partnership is
demanding during the project phases
bull Design-bid-build After the architectrsquos design has been approved by the client a
competitive bidding process takes place This results in a greater disconnect between parties The
common gap between participate happen a lot in this type of contract which frequently can cause
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
47 | P a g e
misunderstandings about responsibilities of each expert incomplete information about the project
design or executive details and lack of transparency among the participants
bull Negotiated bid The modular manufacturer is hired first by the client to find the
appropriate architect and onsite general contractor that can be hired within the constraints of a
budget This concept may increase bonding between experts and improve everyonersquos understandings
about many aspects of the project But the budget will decide whether the quality level design
enhancement can meet the clientrsquos requirements or not In addition in case of clientrsquos approval the
question would be the future userrsquos satisfaction can be achieved or not due to the budget limitations
on the project quality level
bull Certified Modular Architect (CMA) A sustained relationship between an architect
and a manufacturer can be developed over multiple projects Therefore a certification process
providing training and continuing education can be introduced to the modular building industry An
architect intimately familiar with modular construction is best suited to handle coordination issues
that arise when work is being done in the factory and onsite simultaneously A it mentioned earlier
architects understanding and knowledges is critical to avoid possible mistakes and unsuitable designs
for modules Therefore this certified education which can be called as a semi-professional internship
for the design team in order to be present at every phase of the project
Supply chain-transportation-onsite assembly management errors
One of the main objectives to use prefabricated elements in construction is to raise the
productivity in execution phase which is mostly happens in off-site plant As it mentioned before there
is a supply chain in manufacturing plant and its productivity is depended to many key factors which
will happen outside of the factory Continuity of assembly operation is one of them which would be
happening in parallel with off-site supply chain After the modules were prepared to be transported
to the site the transportation system must be synchronized with the factory delivery and assembly
demands If any delays may happen during the transportation would affect the both origin and
destination scheduling storage policies and demands
On the other hand assembly line also must on-time and well-communicated with off-site
plant experts because any changes in execution phase can make huge negative impacts on supply
chain productivity Therefore these three important phases must plan based by on-site demands
supply chain productivity execution management and transportation systems
Figure 2 51 - synchronization between supply chain transportation and on-site assembly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
48 | P a g e
3 Common challenges in modular construction industry by a
survey Methodology
Objective
This study used qualitative research and specifically a grounded theory methodology to
uncover more information about advantages of modular construction and its constraints or barriers
to develop this method in the market Qualitative research emphasizes the influence of the researcher
on the data collected
Role of the researcher
In this study I acted as the sole researcher who was responsible to design questions based by
literature reviews and then by creating an online survey form try to collect the data from the
participants
Ethical considerations
To protect the rights and guarantee the safety of participantrsquos information following actions
were done
1) The research objective and process were made clear to the participants
2) The collected data was used for research objectives only
3) Only eligible participants who are modular constructors and manufacturers were
chosen for this survey
4) The access option to the survey information gave to the participants after the
research was finished
5) The anonymity of the participants was maintained
6) The name of the participant and their brand was remained confidential for all roles
even the researcher to obey the law of data protection
Survey setting
Due to the emergency restrictions which caused by a virus pandemic across the world several
options were unavailable to be done such as face to face interviews factory visits and project site
practices Therefore online interview was the only solution which can be happen without any danger
for participants and researcher In most regions construction companies are suffering from a full shut
down on their production line and on-site projects so that access to these participants became even
harder than usual Thus an online survey form by office forms was chosen for this research so that
the participants can answer the form questions at any time and location with ease to answer by
multiple accesses to the formrsquos link (Figure 31)
This survey forms had been sent by email to the official addresses that were mentioned in
their websites for contact The priority in choosing the recipients were the construction managers
project managers and executive engineers so that the information will be collected from the operation
managers who have the most technical experience and have the most knowledge with construction
phases from off-site production to on-site installation This could also help the survey to find the
challenges during the construction that were not able to be visited due to the restrictions of global
pandemic
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
49 | P a g e
Figure 3 1 - Online office forms for survey use
The estimated time was reduced to 13min with the most important questions to improve the
efficiency and be timely reasonable for the participants
Development of questionnaire
After hours of study on numbers of articles which have focused on challenges in modular
construction industry several were found that have lack of scientific scope and recommended
solutions Therefore many of the questions were designed to first shed a light on the potential
advantages which have not been mentioned specific and completely unknown for the industry For
instance the social benefits which came immensely useful during the COVID-19 pandemic for health
centres and medical infrastructure etc Moreover a lack of inconsistency between industry and
science came to notice which shown a massive gap between these two important roles in construction
industry This gap explains that the scientific researchers in some areas have the minimum contact
with industrial players in construction world in comparison with other industries which the opposite
situation is applied To fill this gap questions were designed in a way which have an origin of scientific
researches and direct and first-hand information from the construction industry players which are
constructors modules manufacturers etc
Development path of questions can be explained as critical path to the best details of each
criteria than can obtain useful information from participants In terms of advantages the benefits
which were identified from literatures were ordered and asked form participants to be confirmed and
validated by the industry players in real project cases For instance in an environmental point of view
Reduction in Energy Consumption was identified in literatures and had been asked among participants
to confirm the hypothesis that modular construction can reduce the energy consumption in
comparison with traditional methods (Figure 32)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
50 | P a g e
Figure 3 2 - Questionnaire development
Participant profile
Experience amp professions
As the ldquoTable 31rdquo explains information from five companies have been selected for this
survey with variety of backgrounds from pioneers to well-experienced players in industry with over
than 120 years of experience in the modular construction society as constructors and modular
manufacturers The experts who answered have different roles in the industry from CEO to architect
and sales managers so that the data can have more perspectives of views on the questions such as
sales market and design process to project management Table 3 1 - Participantrsquos profiles
Because of diversity in the influence of challenges between massive international builders and
local players these five companies responds have been compared to each other from company C
which is a local constructor to company E that is currently executing modular projects in 80 countries
with approximately 6000 modules build annually
Types of materials in some cases can have different statistics in results For instance in
modular construction which steel and wood modules are more often used in projects can produce
various amount of CO2 emissions and waste or recycle process can be done with more ease For that
reason these survey all types of materials are considered including steel modules concrete modules
and wood modules There is also an argue that some benefits and challenges cannot be seen in unique
projects with more repetition in production of elements and mass production such as hotels and
schools while in residential projects can exists more than the others To cover all the contrasts of
60 of participants
can acheive a 30-40
reduction energy
consumption
A Our homes are not positive from an energy
perspective
B We can finish a 4 months traditional project in 8-10 weeks and Energy consumption of a factory is known and relatively constant on a weekly
E 30 reduction in energy consumption
Modular construction can
reduce the energy consumption up
to 30 in compariosn with
conventional methods
QsCompany A B C D E
Years of company experience 10-15 10-15 20-30 20-30 30-50
Position of participant CEO Sales Manager Design Architect Quantity Surveyor Foreign Trade Manager
Professional experience 15 13 30 NA 3
No of employeesfactoryModules build annually 801200 1301490 151- 50280 25026000
Type of material(WoodSteelConcrete) W amp S W W W S amp Conter amp fiber cabins
Types of Projects (ResedentialSchoolsHospitalCommercial) R R amp S amp C R R amp S amp C amp H R amp S amp C amp H
Use of BIM Yes No No No No
Level of automation 20 reaching up to 80 20 Off-site 60 On-site 20 20 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
51 | P a g e
information these companies have been selected that are involved in all types of modular building
projects including residential hospitals schools and commercials buildings
As it mentioned before BIM program can advance the projects in many ways however
unfortunately among these participants only company A is able to benefit from this software from 0
to 100 of the project Therefore the further arranged interview focused on BIM Function was
cancelled and may be done in the future investigations
Automation can play an important role in improving the productivity and sustainability of
construction processes as a part of ldquoindustrialization in constructionrdquo movement Among survey
participants the minimum automation level in off-site plants is 20 and maximum of 60 and in on-site
activities can be up to 40 In addition company A claimed that in near future their automation can
reach up to 80 which is an innovative move in construction industry On the other hand company
with over than 6000 modules build annually have a significant 60 of automation in their plant which
shown a massive interest of investment on this technology In addition automation application
difficulty have direct relation with the type of materials used in modules and type of the projects which
as Table 31 illustrates company E with the most variety in project types and materials use have
achieved a huge success in application of automation with a level of 60 which also helped a lot to
expand their market overseas
Data collection
General information
All the received information has been attached in ldquoAnnex 1rdquo where the responds are not
edited and mentioned in the original shape Here are the shorter versions of responds
bull Motivations to choose modular construction over traditional
To bring the attention of investors to an innovative method reasonable motivations are
needed which can be the current demands of market economic profits and environmental benefits
Therefore it was necessary to identify the motivations of these companies to start a modular
construction form Economic advantage for most of these has a priority not just for being profitable
but for being able to develop their dominance in the future On the other hand innovation has an
approximately same amount of interest which explain the reason behind choosing modular method
that is one of the most innovative off-site construction methods in the industry
The fact that mentioned before in literature reviews high demands in the market and the lack
of provide by construction players is one of most important reasons to apply a fast and high-quality
solution for reach the satisfaction of housing market Shorter schedule and environmental benefits
took the next places of priority in motivations for these companies which are also important for sure
Figure 3 3 - Participants motivations to start a modular company
28
9
18
18
27
Economic benefits
Enviromental benefits
Shorter schedule due to the need
High demands of housing in themarket and lack of provide
Innovation
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52 | P a g e
bull Built in factory panelssubcontracted panels used in modules
All five companies are manufacturing the panels that used in modules by their own inside the
off-site plant which as it mentioned earlier the selected participants have a variety of production rates
and by this information that they are able build their own panels it can be said that their production
is 100 off-site However in the case of company E which is a massive international modular player
there are some types of modules that are being provided from domestic market because of economic
feasibility issues
Economic issues
bull No of labourLess wages of salaryAdded value in each hour of workneed of
special workforce
Generally the participants mentioned that there fewer number of workers are needed on and
off site in comparison with traditional method About the amount of salary wages company A
confirms that for each hour of work off-site less amount wages are being paid to workers On the other
hand the shorter schedule of projects in modular projects can reduce the payments as well The fact
that most of the participants are emphasizing is that the efficiency of work and added value of
activities off-site are much more than the on-site traditional projects where company A acclaimed
that in terms of efficiency ldquo1 hour in the factory is equal to 4 hours on-siterdquo
Environmental status
bull Life cycle duration of products and material recycle
Company B acclaimed that they do have multiple solutions for each materials that theyrsquore
using in their modules for instance the unusable drywalls and PVC materials which they send for
recycling or the woods that would use into mulch products or for heating by others
Company E told that their products have a 50 years life span which is the same as a lifetime of
traditional build residential house However company C have some difficulties in recycle and reuse of
their elements because of unportable feature of their products
bull Integration the modules with other innovative technologies
Four of these five companies confirmed that their products have the option to integrate with
other innovative technologies such as self-powered homes by solar panels and also using advanced
insulation technics made by non-petroleum materials in their panels to reduce the energy
consumption during operation phase
bull Waste reduction
Company A acclaimed that their production line generates significant amount of 70 less
waste in comparison with traditional method The rest of the companies focused on carbon footprint
reduction and were able to reduce it 15 less that traditional method by choosing environmentally
friendly technologies in production and wise choice of materials for their products
bull Reuse of structural and non-structural elements in projects
Three of five participants confirmed that they have the ability to re-use their products in the
next projects in order to reduce the waste and energy consumption during the manufacturing
processes Type of the projects and material have the direct relation with the potential of reusability
in elements and due to the variety that the participant have in both criterions the potential is variable
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
53 | P a g e
Figure 3 4 - Re-use potential
bull Reduction in Energy Consumption
Company E mentions that modular construction can achieve a 30 of energy saving in
comparison with traditional site-build method while company A acclaimed that their homes are not
positive from an energy perspective Company B gave more details on energy consumption by making
a comparison between off-site activities and on-site traditional construction and acclaimed that due
to the shorter schedules in off-site production energy consumptions can be reduced up to 50 They
mentioned that ldquoEnergy consumption of a factory is known and relatively constant on a weekly
monthly and annual basis A competent and experienced modular builder can many times finish the
entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-
built house could require as much as 4 months for the same completionrdquo
Social Benefits
bull Delivery of projects for emergency services during COVID-19 Period
As it mentioned earlier due to the virus pandemic that is happening at moment in all around
the world a rapid response is needed more than ever for emergency services for health organizations
and according to this survey one of these companies is providing products for this cause which can be
a good news and accounted as a social benefits for this method of construction
Figure 3 5 - Contribution in Covid19 epidemic
bull Providing post-sale services for clients
In contrast with conventional construction which just have the responsibility until the delivery
of the project modular constructors because of their industrial profile have the ability to offer post-
No40
Yes60
Reuse the structuralnon-structural elements projects
No
Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
54 | P a g e
sale services to the clients such maintenances upgrades etc due to the results of this survey four of
these five companies confirmed the availability of post-sale services for their clients
Figure 3 6 - Post sale services por future clients
Initial costs
bull Initial investment and its Payback period
Company A claims that their initial investment to establish their company was about 20 million
Canadian dollar and its payback period was 5 years Company E had the amount of 15 million USD with
the same 5 years period However company C like many of the older players in modular construction
industry who started way earlier cannot estimate their initial investment
bull Factors that can change the initial costs
There are factors which can make a change in initial costs of companies The participants
prioritized these 6 chosen factors starting with product types and production range with 31 of
importance among others Level of automation took 25 share of the pie chart which has direct
relation with the initial costs Off-site plantrsquos location has 19 of efficiency on starting costs and
furthermore the quantity of sub-contracted players in the projects achieved 13 of the graph Finally
financing and design enhancement have the minimum equal shares of 6 which despite of being the
last factors have the efficiency on initial costs as well
Figure 3 7 - effective factors in initial investments for start-up companies
6
25
31
13
19
6
Factors that effect on initial costs
Design enhancment Level of automation
Product types and production range Less sub-contracted
site location Financing
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
55 | P a g e
Design limitations
bull Design boundaries caused by production line
Company A mentioned the subassemblies as the main element to be considered in design
phase while company D and company B introduce a maximum dimension for their production lines to
be economically viable for transportation costs In addition to those company C and company E
confirmed that there are no boundaries for the designer caused by the production lines because of
their wise choice of prefabrication methods
bull Lack of knowledge from architectsdesign engineers about production processes
transportation limitations etc
One of the main problems of start-up companies and the experts who join the modular
construction industry is the lack of knowledge about off-site processes and transportation limits
Three of five participants confirmed that there is lack of knowledge in these area from designers
Figure 3 8 - Lack of knowledge among designers and engineers
Transportation Limitations
bull Transportation regulation effects on modular projects
Three of five participants confirmed that the regulation by transport administrative can be
harmful for the projects such as extra costs or time delays on schedule Company A mentioned the
time delays in giving permits to the manufacturers and constructors which can damage the
synchronization between production line and on-site installation by reducing the speed of
transportation of elements to the site Company B added information about transportation system of
some states in America which use the term ldquoSuper Loadsrdquo to put limits on oversized shipping that
increases the cost and time on the project On the other side Company C as a strategy to avoid this
problem used legal load limits in their design instructions so that their products will obey the
regulations
bull Transportation boundaries on material choice and project costs
Company B D and E confirmed that the terms of special transportable material will not add
extra costs on the project Company A acclaimed that the extra costs by transportation can be offset
by speed of production and reduced financing costs for the project
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
56 | P a g e
Project management challenges
bull Difficulties in using automation in off-site production
In this survey based on literature reviews 4 main reasons for difficulties of using automation
in off-site production were selected to ask the participants Integration with advanced software and
high expenses of application in production line took approximately 60 of importance among others
Codding problem is another major problem in this subject which have 28 of pie chart In addition
company A demanded ldquoAn international coddingrdquo as a solution for this problem The last section
belongs to ldquolower salaries of manual processesrdquo which has the minimum importance of 14 among
participants
Figure 3 9 - challenges of using automation in off-site plants
bull Contracting problems
Starting with company A which acclaims that every state has its own code and the lack of a
universal code can bring challenges for modular players
Company B explained about the misunderstanding by final client who is the end home buyer
who ldquobelieves the factory to be the builder and the actual independent builder to be a sales agent
for the factoryrdquo Their recommended solution for this problem is to define the relationship between
the participants of projects their responsibilities by social media and requiring the builders customer
to sign a disclosure acknowledgement from that describes the relationship in detail
Company C mentioned a financial challenge caused by the banks in the projects that are
financed by them (Banks) which do not consider the project done until erected on-site This issue
creates pressure on cash flow of project where bank finance is involved The only problem that
company E consider in terms of contracts is lack of timing on project delivery which is generally causes
by constructors or general contractors
bull Lack of synchronization between projectrsquos participants
To begin with company A believes that there is a lack of quality partners on site They explain
that the problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution Company B mentioned that the responsibility of ensuring
28
29
29
14
Difficulties in using automation in off-site production
Codding Integration with advanced software Cost Lower salaries of manual processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
57 | P a g e
that the work is done properly belongs to the builder which any ldquodelays in this can result in postponed
transport of product and interest through demurrage charges
bull Sub-contractor for site planning and foundation phase
Company A uses local subcontractors for their site planning and foundation phases because
of variety of locations of their projects and ease of using local subcontractors Company B have only
the responsibility of modules production and defines the customer (the general
contractorindependent builder) responsibility to execute rest of the project phases have sub-
contractors if needed Company C does have sub-contractors for site-preparations and foundation
phases under direct supervision and the reason to not performing by their own is the high costs of
required equipment and not being portable for each project
bull Technology gap between sub-contractor and modular constructor
The only issue that were mentioned by participant is where company A recommended to ldquoto
educate most local subs on our process and reason for doing things a certain wayrdquo
Company B and C acclaimed that there are no challenges for the off-site production
Social challenges
bull Wrong perceptions among public and market
The only value that the market considers choosing modular method over traditional
construction is to be cheaper Company A says
According to company B experience in USA majority of people the media and even
professional engineers do not understand the capabilities of modular construction Many people
continue to confuse this form of construction with HUD on frame products
Another wrong perception that the publicmarket believes is that the prefabrication methods
limits the design options while Company C believe confirms that the reverse is the case
bull Solutions for resolving the wrong perceptions
Company A believes by using one of the main advantages of modular construction which is
shorter schedule the market can be dominated by modular projects and the more cases they deliver
the more recognised this method would be among the public and at the end the superior nature of
modular approach can be proved Company B addresses a solution in a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Company C acclaimed that advertising the modular advantages
among the public would be enough
Data analysis amp conclusions
The data from this survey can be used as an input data and prioritizations for the next chapter
which is decision-making process between four alternatives The solutions and recommendation will
be repeated at the recommendations at the final chapter as well Here are the conclusions about
advantages and challenges in modular construction mentioned by professional participants
Advantages
Economic benefits Generally apart from the other benefits as the participants mentioned
that there fewer number of workers are needed on and off site in comparison with traditional method
and Due to the shorter schedule of projects in modular projects can reduce the payments wages
Other fact that most of the participants are emphasizing is that the efficiency of work and added value
of activities off-site are much more than the on-site traditional projects
Environmental benefits Due to the variety of solutions for each material that they are using
in their modules there is high potential to send the used elements for recycling or would use into
mulch products A long lifetime span is acclaimed for the products which is close to the traditional
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
58 | P a g e
ones Majority of participants confirmed the literature concept that their products have the option to
integrate with other innovative technologies such as self-powered homes by solar panels and also
using advanced insulation technics made by non-petroleum materials in their panels to reduce the
energy consumption during operation phase In the waste management term there is a possibility for
production lines to generate significant amount of 70 less waste in comparison with traditional
method Moreover about carbon footprint reduction there is ability to reduce it 15 less that
traditional method by choosing environmentally friendly technologies in production and wise choice
of materials for products While there is argue that modular construction can achieve a 30 of energy
saving in comparison with traditional site-build method there are claims that their homes are not
positive from an energy perspective However this idea mentioned that by making a comparison
between off-site activities and on-site traditional construction due to the shorter schedules in off-site
production energy consumptions can be reduced up to 50
Social benefits As it was mentioned in literature reviews there are social benefits in modular
construction that can improve the satisfaction of clients Post-sale services for customers are possible
which is completely opposite to the traditional projectrsquos conditions
Challenges discussion
Initial costs It is obvious that a high amount of investment is needed to stablish an off-site
plant to start prefabrication of construction elements but the payback period is not that long that put
boundaries for start-up future players due to the collected information There are factors which can
make a change in initial costs of companies that are prioritized by the participants starting with
product types and production range level of automation which has direct relation with the initial
costs Off-site plantrsquos location the quantity of sub-contracted players in the projects and finally
financing and design enhancement have the minimum equal shares
Financial aids Financial assists which are crucial for kind of projects that are dependent to
these aids are not harmonized with modular project processes where there are argues that until the
first deliveries of elements to the site location and their assembly these aids are not reachable This
issue creates pressure on cash flow of project where bank finance is involved Changes in contract
conditions and education for financial supporters are recommended solutions to improve the
partnerships in projects
Design boundaries it was mentioned the subassemblies as the main element to be
considered in design phase while some players introduce a maximum dimension for their production
lines to be economically viable for transportation costs However there a possibility to eliminate the
boundaries for the designer by the production lines because by wise choice of prefabrication product
types
Lack of education The idea of lack of education among engineers and architects about off-
site construction methods was proved by the collected information which have to be resolved by
updating the education resources to innovative methods that can improve the productivity rates and
sustainability
Transportation regulations negative effects it is confirmed that the regulation by transport
administrative can be harmful for the projects such as extra costs or time delays on schedule Time
delays in giving permits to the manufacturers and constructors which can damage the synchronization
between production line and on-site installation by reducing the speed of transportation of elements
to the site A strategy to avoid this problem used legal load limits in their design instructions so that
their products will obey the regulations
Choice of transportable material effect In contrast with literature review which mentioned
the idea of extra costs by choices of transportable material this survey confirmed that the term of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
59 | P a g e
special transportable material will not add extra costs on the project Moreover the extra costs by
transportation can be offset by speed of production and reduced financing costs for the project
Automation use challenges Integration with advanced software and high expenses of
application in production line took approximately 60 of importance among others Codding problem
is another major problem in this subject In addition ldquoAn international coddingrdquo was mentioned as a
solution for this problem Every state has its own code and the lack of a universal code can bring
challenges for modular players ldquolower salaries of manual processesrdquo has the minimum importance
Defining responsibilities boundaries There is a misunderstanding by final client who is the
end home buyer who ldquobelieves the factory to be the builder and the actual independent builder to
be a sales agent for the factoryrdquo Their recommended solution for this problem is to define the
relationship between the participants of projects their responsibilities and requiring the builders
customer to sign a disclosure acknowledgement from that describes the relationship in detail
Lack of partnership among projectrsquos participants There is a lack of quality partners on site
The problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution The professionals answered that the responsibility of
ensuring that the work is done properly belongs to the builder which any ldquodelays in this can result in
postponed transport of product and interest through demurrage chargesrdquo
Wrong perception of publicmarket The only value that the market considers choosing
modular method over traditional construction is to be cheaper while majority of people the media
and even professional engineers do not understand the capabilities of modular construction Many
people continue to confuse this form of construction with HUD on frame products Another wrong
perception that the publicmarket believes is that the prefabrication methods limits the design
options while some players believe that the reverse is the case Therefore by using one of the main
advantages of modular construction which is shorter schedule the market can be dominated by
modular projects and the more cases they deliver the more recognised this method would be among
the public and at the end the superior nature of modular approach can be proved Another solution is
a form of cooperation between builders manufacturers architects and engineers to educate the
public by national entities such as Modular Home Builders Association
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
60 | P a g e
4 Decision making based on potential advantages among three
modular alternatives and conventional construction method in a
project by MIVES software Methodology
Objective
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria potential benefits can be recognised However to find out how much practical these benefits
are in the market several trade-offs must be done by professional tools such as project management
software programs which can take decisions based on the input data that receive
The objective of these thesis is to examine the practicality of modular construction by taking
the best decision among 4 alternatives including a conventional armed concrete building with steel
modular concrete modular and timber modular methods and see that the mentioned advantages can
lead the methods to become the best option to choose for building the project as a project
management point of view
What is MIVES
In order to make the most sustainable and reasonable decision among the alternatives a multi-
criteria decision-making program was used called ldquoMIVESrdquo MIVES is the acronym for Modelo
Integrado de Valor para una Evaluacioacuten Sostenible which means Integrated Value Model for a
Sustainable Assessment It is a multi-criteria methodology for decision making It allows transferring
the different characteristics of the objects to be evaluated to a series of homogeneous and
quantifiable parameters which facilitate the objectification of the choice
The MIVES methodology consists of creating a model that defines all the characteristic
features of the elements to be evaluated assigning them a function that allows converting the
different peculiarities of the alternatives into a common unit which we will call value Once the
amount of value for each alternative is obtained it can be used for a sustainable evaluation
(wwwdecaupcedu)
Data collection process
Case Study references
bull Journal of Cleaner Production (WAHammad 2019)
(httpsdoiorg101016jjclepro201904150)
This Fabolous multi-criteria comparison was done between two methods of conventional and
steel modular building in two cases case A which is a normal residential building and case B a school
building to measure the sustainability level of them in economic environmental and social areas The
location of this was considered in Sydney and central coast Australia and four BIM models had been
designed for each alternative in both cases The total floor area of Case A is 63 m2 (87m x 72m)
When adopting modular construction the granny flat is designed from 2 modules each module is
36m x 87m Case A was chosen as the study case to focus on because of type of the project that is
residential building
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
61 | P a g e
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study (WAHammad 2019)
The purpose of this journal is to add sustainability criteria as main factors for constructors to
make a multi-dimension decision whether to use Modular construction for a project or continue with
conventional methods
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and conventional methods
(Akbarnezhad 2019)
bull A comparative life cycle assessment (LCA) of concrete and steel-prefabricated
prefinished volumetric construction structures in Malaysia (Ali Tighnavard
Balasbaneh 2020)
(httpsdoiorg101007s11356-020-10141-3)
This researchrsquos focus is to compare two types of volumetric modules function in terms of cost
and LCA factors such as Greenhouse emission etc on a residential project with the approximate area
of 105m2 located in Malaysia based on local regulations Prefabricated Concrete Modules (PCM) and
Prefabricated Steel Modules (PSM) were considered for this project Recently Malaysian
administrative system has been pushing the companies and researchers to investigate on these types
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
62 | P a g e
of construction methods in order to measure the benefits and obstacles of using them in future project
and try to resolve the productivity problem in construction industry The construction industry in
Malaysia has been labelled ldquounproductiverdquo for its reliance on a large labour force and its use of non-
prefabricated strategies at a proper scale (Balasbaneh 2020)
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020)
bull Modular vs Conventional Construction A Multi-Criteria Framework Approach
published at ISARC 2017 (AWA Hammada and A Akbarnezhad 2017)
This paper did a comparative analysis in cost time and carbon emissions by BIM models
Material and equipment libraries and existent databases on a project in the North-West of Sydney
involves the construction of a granny flat with dimensions 14 m by 16 m
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017)
The framework of this papers based on the BIM model analysis with input data project actual
projectrsquos budget material and equipment used in the construction and environmental information in
database and then a comparative study on emissions during constructionmanufacturing schedule
and costs of project for crew material and equipment (Figure 45)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
63 | P a g e
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad 2017)
bull Life cycle greenhouse gas emissions and energy analysis of prefabricated reusable
building modules published on Energy and Building (Lu Aye 2011)
(httpsdoiorg101016jenbuild201111049)
Aye and his team did a LCA study on three alternatives PSM PCM and PTM which were used
in a multi-residential building with 63 apartment units with area of 63 m2
Figure 4 6 - Architectural section of multi-residential building (Aye 2011)
The modules in this study were categorized in 4 main elements Exterior walls with insulation
panels Interior walls used for internal separation which mostly build with timber frames and plaster
boards Floors with plywood material on topping in all alternatives and ceilings with thick plaster
boards and steel concrete and timber parts as main elements (Figure 47)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
64 | P a g e
Figure 4 7 - Structural elements used in modules (Aye 2011)
bull Comparing Environmental Impacts of Building Modular and Conventional Homes in
the United States published at Construction Matters (John Quale 2012)
(httpsdoiorg101111j1530-9290201100424x)
Quale did also a comparative analysis focused on Environmental emissions on two PTM and
Conventional Timber building Three residential modular companies generally representative of the
eastern US modular industry supplied data on completed projects for this study including utility
bills worker commuting information building materials and waste procedures construction
schedules employee schedules and other relevant information (Quale 2012) 186 m2 two-story
home that is a model for one of the companies involved in the study
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
65 | P a g e
Input data
4221 Alternatives
Four alternatives were selected for these study which are one conventional armed concrete
(Reinforced concrete RC) structure prefabricated steel modules (PSM) prefabricated concrete
modules (PCM) and prefabricated timber modules(PTM) that are most common solutions used by
contractors in the construction industry
4222 Requirement tree
These are groups of criteria which define a function to be evaluated A requirement usually
has several criteria Five requirements were selected based by literature review and the expertrsquos
opinions collected by survey among industrial players who were the participants of this questionnaire
Economic R1 time R2 environmental R3 safety R4 and social R5 requirements arranged in a way that
can examine the advantages adequately Time requirement were separated from economic one
because of importance due to high priority that have in the market to be chosen by the constructors
and clients In other words some clients and private builders choose the prefabrication methods such
as modular construction to save more time due to tight schedule that the project have Social and
safety requirements usually not being considered in sustainable decision-making processes but on this
study were included because the sustainability is not the only factor in project management
4223 Criteria
For each requirement a series of criteria are defined Criteria are the specific concepts that
the indicators contain the minimum unit to be quantified (wwwdecaupcedu) Each criterion was
chosen based on the importance among others efficiency on the project and availability of actual
amount and quantities in real cases over literature resources In other words the both advantages
and their functionality that modular construction have in comparison with traditional methods were
the main drivers to choose a criterion for each requirement as it mentioned earlier For economic
requirement cost of the project R1C1 was the only criteria that was considered which in the literatures
is expected to save 20 by choosing modular method in final cost (McKinsey amp Company 2019) while
experts in survey believe that the cost of transportation of prefabricated elements to the site can
compensate the difference with traditional method To examine these two opinions these criteria was
chosen In Time section the projectrsquos schedule R2C1 was only criteria to measure the important
advantage that the modular construction has Both literatures and expert agreed the time saving that
modular approach can bring to the project which is about 50
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES)
R1 - Economic
R1C1 - Project cost
R2 - Time
R2C1 - Project schedule
R3 - Environmental
R3C1 - Energy consumption
R3C2 - Waste generation
R3C3 - Material consumption
R3C4 - Noise Polution
R3C5 - Greenhouse gas emission
R3C6 - Recycle
R3C7 - Embodied energy
R4 - Saftey
R4C1 - Injury risks
R4C2 - Protection from natural cuases
R5 - Social
R5C1 - Job status
R5C2 - Quality
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
66 | P a g e
Seven criteria were chosen to cover the environmental requirements for this decision-making
process based on the available data in literatures However in this section not only advantages of
modular methods were considered but in some areas conventional reinforced concrete showed
better results and this fact can improve the liability and practicality of final decision For instance the
embodied energy of steel modular building is 30 more than the conventional during the construction
but the saving caused by re-useability of element in modular method can almost compensate the gap
between these two methods Energy consumption R3C1 which is the energy consumed during the
constructionfabrication amount of Waste generated R3C2 in all alternatives Material consumption
R3C3 in each method Noise pollution R3C4 Greenhouse gas emission R3C5 Recycle of elements R3C6
and Embodied energy for each method were chosen in this section
Safety issue as it has mentioned before was added to decide further than sustainability
concept boundaries which include two criteria Injury risk for workers R4C1 and Protection of project
from nature causes R4C2
Finally Social benefits which are not as main factors to be considered by construction players
to use the modular methods but are important enough to pay attention and were compared as well
by two criteria Job status R5C1 and Quality R5C2
4224 Indicators
The indicators for this study came directly from scientific articles which most of them were
published few months ago and it can be said that the data which were used for this study is updated
with the latest achievements in modular construction industry
To begin with for economic measurements two indicators for the project cost were selected
total project cost R1C1I1 and costs stability R1C1R2 Total project cost R1C1I1 for conventional RC
alternative means the final cost of construction including all the activities until the delivery of building
In modular alternatives PSM PCM and PTM includes the module fabrication in off-site plants
transportation installation on-site and final finishing of building after the assembly phase All
indicators are based on ldquoAustralian dollarsrdquo units (AUSD) because of the recourse quantities that was
used for this study which will be discussed more later Second indicator which is the costs stability
(R1C1R2) was chosen because of the common off-site production economic advantage that is
stabilizing the costs for the projectrsquos budget because of high quality of product more repetition of
elements and more accurate supervision on activities which leads to less reworks and less extra costs
etc
Total project schedule R2C1I1 is the first indicator for time requirement which include the
amount of time to fabricate transport and final assembly of the modules on-site in modular
alternatives and the final schedule of the conventional project during construction activities until the
delivery of the building which all are based on ldquodaysrdquo it was mentioned earlier that in off-site
production the project schedule can be estimated and controlled more adequately so that second
indicator which is time stability R2C1I2 was introduced to the study
Environmental requirement was studied in various features as it said before in 7 criteria which
shows the complexity of comparisons between alternatives First indicator is the Energy utilized during
construction R3C1I1 based on ldquoMJrdquo units Solid Waste R3C2I1 is the only indicator for Waste
generation criteria that focuses on the amount () of waste which was produced during
constructionfabrication activities in all four activities In material consumption criteria the total
amount of materials that was used for constructionfabrication of elements R3C3I1 is appointed as an
indicator to compare the benefits in each alternative based on ldquoKgrdquo Noise reduction in off-site
construction is another benefit that it has and to discuss this fact among the alternatives Average A-
weighted equivalent sound level of each construction equipment R3C4I1 based on ldquodBrdquo units was
focused on Greenhouse gas emission among alternatives was measured in CO2 that was produced
during constructionfabrication activities R3C5I1 based on ldquoKGrdquo units Two indicators were introduced
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
67 | P a g e
for recycle criteria between four alternatives recyclability or possibility of recycling of elements
R3C6I1 and Re-use of elements (Products) in projects R3C6I2 based on Percentages Embodied energy
was the last criteria which was focused on with two indicators Embodied energy used R3C7I1 in ldquoGjrdquo
units and Embodied energy saved by re-use of elements in percentages among alternatives
For safety measurements two indicators were selected for two criteria which are injury risk
level R4C1I1 for injury risk criteria and Protection level R4C2I1 for protection from nature causes both
in a qualitative unit
Job stability R5C1I1 for comparing the job status in terms of security of jobs among two
methods and new job creation R5C1I2 to analyse the possibility of providing new job positions which
is crucial in these era in construction industry were chosen in qualitative unit
The last criteria in social requirement which is quality of projects was presented with one
indicator of quality satisfaction of client R5C2I1 in qualitative unit to compare the clientrsquos satisfaction
level between alternatives Table 4 1 - Requirement tree with all indicators which considered for decision making process
Requirements Criteria Indicators
(R1) Economic (R1C1) Project Cost (R1C1I1) Total Project Cost
(R1C1I2) Cost Stability
(R2) Time (R2C1) Project schedule (R2C1I1) Total Project Schedule
(R2C1I2) Time Stability
(R3) Environmental
(R3C1) Energy Consumption (R3C1I1) Energy Utilized during construction
(R3C2) Waste Generation (R3C2I1) Solid Waste
(R3C3) Material Consumption (R3C3I1) Material Consumed in project
(R3C4) Noise Pollution (R3C4I1) Average A-weighted Equivalent sound Level of each instrument
(R3C5) Greenhouse Gas Emission (R3C5I1) Co2 in constructionfabrication
(R3C6) Recycle (R3C6I1) Recyclability of Elements
(R3C6I2) Re-use of elements
(R3C7) Embodied Energy (R3C7I1) Embodied Energy Used
(R3C7I2) Embodied Energy Saved
(R4) Safety (R4C1) Injury Risks (R4C1I1) Injury Risk Level
(R4C2) Protection from Nature Causes (R4C2I1) Protection Level
(R5) Social (R5C1) Job Status
(R5C1I1) Job Stability
(R5C1I2) New Job Creation
(R5C2) Quality (R5C2I1) Quality Satisfaction of Client
The input data for indicators are categorized in 4 types direct data calculated data estimated
data and qualitative data The reason for not having only direct data is the lack of enough literature
researches on this subject and in some cases the data were published two months before the date of
this study The variety of alternatives which is the first time that a study is going to analyse 3 modular
alternatives and a traditional method added difficulty to find useful data to do the decision making
reliable Moreover 5 articles were used for finding the correct data which each of them focused on
different alternatives The orientation of this study is the Cleaner Production journal by professor
Hammad that was published in 2019 which was mentioned earlier The reason of this orientation is
that most of the data came from this article and is more updated than the others
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
68 | P a g e
bull Direct Data
The direct data were the information that was related precisely to the alternatives without
any needs to change For instance the cost of the construction in Hammadrsquos article which can be used
without any changes The green parts on the Table 42 shows the direct data which are related to the
Hammadrsquos article Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed to be done on them
bull Calculated Data
In many indicators because of lack of existence in directly related data for alternatives a sort
of calculations were needed to change the data from other articles that related to alternatives that
are not focused in main case (Hammadrsquos article) to actual data based on the area of main article by
using accurate coefficients and ratios For instance in Hammadrsquos article CO2 was not estimated for
Prefabricated Steel Modules (PSM) alternative but Ayersquos CO2 data which is for total area of 3943m2
with 63 apartments each area of 628 m2 (close to 625 m2 area of Hammadrsquos granny flat) was used
by dividing on 63 apartments units so that results 54079 kg of CO2 for steel modular equivalent for
main case The yellow parts show the calculated data for indicators
3407000119896119892 1198881199002 divide 63 119906119899119894119905119904 (6251198982) = 54079119896119892 1198881199002 for steel modules in main case
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other studied
bull Estimated Data
Third type of input data were the necessary data which are not existed on any of literatures
of have to be estimated based on the qualitative information professional survey which have been
done before the decision making process (Chapter 3) and researcherrsquos opinions Fortunately in many
areas the data could be applied on other alternatives because of similarity of activities off-site and
onsite For instance for PCM alternative the noise and Injury risk level are approximately the same
the indicators of PSM case that have mentioned in Hammadrsquos article which are shown in green parts
in Table 42 because of similarity of off and on site activities during construction
The blue parts are the estimated data that were considered for PCM alternative based on
mentioned resources For instance the time indicator can be predicted 24 days few days more the
steel modules which is around 22 days because of the fact that concrete modules are heavier than
steel ones and has more complexity in structure for being produced that adds difficulties on
transportation process which leads to more delays on the schedule Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow)
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
69 | P a g e
bull Qualitative Data
This data was added because of two reasons first the lack of existence of direct data on
literatures and improve the literatures background on this subject and secondly to have more
influence from variety of benefits that modular construction has on the decision making process
Numbers of literatures insisted on advantages that can affect the decision making but did not
included on their data analyses at the end and this research decided to include these data and see
that how much functional can be in the decision making between alternatives in point of project
management view For instance cost stability which is better coordinated in off-site construction and
can be considered as an advantage to the decision making is not included in the literatures during
analysis and in this study is a vital factor for the economic criteria In order to add this indicator a
qualitative range was considered from 0 to 10 and four alternatives based on their functionality in cost
stability in project budget were compared to each other Traditional reinforced concrete building
which because of common reworks etc have less stability in final budget estimation On the other
side PSM and PTM which have the most repetition in manufacturing processes and ease of production
because of material type have the maximum cost stability of 9 out 10 among the others and PCM that
has less ease in production have less cost stability than other modular alternatives with 8 out of 10 Table 4 5 - Qualitative indicators
Final indicators
bull Prefabricated Steel Modules indicators (PSM)
As it mentioned before the direct data which are shown in green at table 46 do not need any
changes as they belong to the main case study while other indicators are still needed to be calculated
estimated and often considered qualitatively Aye case study have the closest data to the main case
study because of similarity of project type and dimensions so that the necessary indicators such as
material consumption waste generation percentage re-use amount and embodied energy indicators
can be calculated from this analytical study (For more information about indicators resources please
see Annex 1-A) Table 4 6 - First hand data over literature
A simple calculation is needed and that is dividing the CO2 emission Material
consumption and Embodied energy used amounts in Aye project on 63 apartment units with the
same area of 625 as main case in Hammads residential flat ldquoWaste amountrdquo ldquore-use of elementsrdquo
and ldquoembodied energy savedrdquo can be applied on the main case because of similarity of material
choices
IndicatorsAltertanives TRC PSM PCM PTM
Cost stability 6 9 8 9
Time stability 6 9 8 9
Recycleability of elements 3 8 7 9
Protection level 2 9 9 9
Job stability 5 8 8 8
New job creation 3 8 8 8
Quality satisfaction 5 9 8 9
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
70 | P a g e
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow)
bull Prefabricated Timber Modules indictors (PTM)
As it can be seen in table 48 there are no enough data over literature in many areas and due
to the necessities for this study a range of calculations and estimation have to be made based on the
similarity of projects among study cases and survey information Table 4 8 - First hand data over literature
Starting with Cost of the project which an ldquoestimationrdquo based on literature review information
and qualitative comparisons (John quale 2012) (Lu Aye2011) that is approximately 45000 AUD
because it proved that the cost of Timer modules is even cheaper than Steel Modules due to simplicity
of material choice and structure design The schedule of PTM building is shorter than the other
alternative because of numbers of reasons such as less weight of elements which can lead to faster
transportation loading and offload in assembly process on-site In addition the manufacturing lines
are simpler than other modular alternatives because of high repetitions and simplicity in design
For ldquocarbon emissionrdquo and ldquomaterial consumptionrdquo Aye project was used by diving on 63
apartment units which have the same area of 625 m2 as main case In terms of ldquowaste generationrdquo a
unique article was used (by Doyoon 2008) which did a LCA study on Timber modular building and the
amount of wastematerial consumed was about 9 The Noise level and Injury risk can be applied
from other modular alternative because of similarity of construction activities and equipment used
for fabrication Energy utilized during construction of Timer modules have the minimum amount in
comparison with other alternatives because of simplicity of material choice and design enhancement
so that was estimated 80MJ which is slightly less than steel modules with 86 MJ
Re-use of elements in timber modular elements was confirmed by survey among the
constructors over than 70 with a life span of 50 years Embodied Energy used was collected from
Aye case study dividing on 63 apartments units as same as other cases which equals to 65671 GJ
(Table 49) Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue)
bull Prefabricated Concrete Modules indicators (PCM)
The least focus on modular alternative was on Concrete Modules which is because of few uses
that this method has among the projects Balasbaneh study focused on a comparison between Steel
modules and Concrete modules in total project cost and LCA Table 4 10 - First hand data over literature
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury risk Energy utilized Re-use Embodied energy Emb saved
Aye 2500000 996 356 41373 691
Quale 13600
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 45000 20 39375 1580952 9 645 163 80 70 65671 691
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Balasbaneh 239380 8264
Units MLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
71 | P a g e
However the currency of this economic analysis is not as AUD (Australian Dollars) as the main
study Therefore to calculate the cost and CO2 footprint corresponding to main study case a ratio
was obtained between concrete modules amounts and steel modules in Balasbaneh study and then
multiplied to the steel modules quantities in Hammadrsquos main case and resulted project cost of
5188603 AUD and 46442 kg of CO2 emissions
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM alternatives
239380 divide 222580 = 1075478 119862119900119904119905 119903119886119905119894119900 (Balasbaneh study case)
482446 times 1075478 = 5188603 119860119880119863 Total project cost of PCM
8264 divide 9623 = 085877 1198621198742 119903119886119905119894119900
54079 times 085877 = 46442 119896119892 CO2 of PCM
The time indicator was estimated based on steel modules but with this difference that
concrete modules weight more than steel ones so that puts pressure on the transportation and
assembly phases and causes delays in the schedule as a result 24 days was predicted to finish the
project
There is no available information on the literature with specific quantitative details however
based on the qualitative structural information prefabricated concrete modules PCM because of their
similarity of material choice to conventional model have a massive material use in comparison with
Steel and Timber alternatives so that an estimated total material consumed of 20000kg assigned for
this indicator (Aye 2011) (Balasbaneh 2020)
Waste generation have a higher ratio in this alternative because of material choices which
generate more waste than other modular alternatives With this fact in mind the waste ratio
considered slightly more than steel kind with 10 (Aye 2011)
Noise level and Injury risk can be applied from other types because of similarity of equipment
and construction activities in all three modular alternatives (Hammad 2019)
Energy utilized during construction in PCM Alternative can be estimated more than steel ones
because of types of materials used in these modules and their high weight with value of 90MJ (Aye
2011)
The structural elements are ldquonotrdquo built in material which have a high recyclability potential so
that decreases the Re-use ratio to 20 approximately in comparison with other modular alternatives
(Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
72 | P a g e
Embodied energy used amount and its potential saving have the minimum value in a
qualitative comparison with other alternatives which respectively values of 800GJ and 60 were
estimated for them (Aye 2011) Table 4 11 - Final indicators for PCM
bull Traditional Reinforced Concrete (TRC) final indicators
The highest focus over the literature is to make a comparison between one of the modular
options and a traditional method which results more availability for direct data for Traditional method
The main case study is not an exception with almost half of the value are available directly such as
Project cost Time Noise level Injury risk and Energy utilized during construction which are shown in
green at table 412 (Hammad 2019) Table 4 12 - TRC first-hand data over literatures
Nevertheless still there are values that must be calculated over literature Green gas emission
indicator and Embodied Energy used were calculated form Ayersquos case study by dividing the values on
63 apartment units which results 3620635kg Co2 emission and 6033 GJ of 625 m2 area as same as
main case study (Aye 2011) (Hammad 2019)
Material consumption have the same methodology as carbon footprint with final value of
626825kg which is massively higher from modular alternatives (Aye 2011) (Hammad 2019)
Waste generation was calculated qualitatively from a literature resource called ldquoModular
Construction for Multifamily Affordable Housingrdquo by WSP which acclaims that the conventional site-
built method produces around 25 times more construction waste (WSP 2018) Thus TRC waste
generation is more than 25 times of modular ones with the value of 15
Two values of Re-use and Embodied energy saved by Re-use of elements were obtained from
Ayersquos case study respectively 22 and 322 (Aye 2011) Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow)
In general the table 414 shows the References and final indicator values that were used for decision
making process (Direct data are shown in Green Calculated data in yellow and estimated data in
blue)
Table 4 14 - Final Quantitative indicators used for decision making process
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 812298 6598 71 217 198
Akbarnejad 120000 67 84672
Aye 2281000 3949 22 38008 322
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
PSM 482446 2131 54079 138254 5 645 163 8593 50 9012 813
PTM 45000 20 39375 1580952 9 645 163 80 70 65671 691
PCM 5188603 24 46442 20000 10 645 163 90 20 800 60
TRC 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrence Ham Aye Balas Hammad Balas Aye Aye Doyoon WSP Aye Hammad Hammad Hammad Aye Aye Aye
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
73 | P a g e
Weights
The Weights (Pesos in MIVES) which are one of the most important factors in decision making
process have be assigned on the data in a way that the priority of each section in terms of efficiency
and importance can decide which value will have among the others AHP method was used to assign
weights on the data In AHP you get the weights through the subjective importance of each element
with respect to the others (Alejandro Josa 2012)
bull Weights of requirments
The importance of requirmenets was assumed based on proffessional survey among
constructors architects sales agents and clients in order to know the demands of market and make
the decision rely on what market expects from a innovative method According to the survey time
reduction is the first priority for choosing the modular methods by constructors and future clients so
than acheived 30 of weight Economic issues came after the time factor because of unconsistency
between responds about cost saving on the budget or offseting the expenses gap by tarnsportation
extra costs on the project Economic requirement has 27 of weight In some regions the priority of
choosing an innovative method are environmental emissions waste generation and recycleability of
products Therefore environmental requirement came after the economic one with 25 of weight
As it mentioned before Social and safety advantages are included in this decision making
process with respectly weights of 13 and 5 because of their less priorities among clients and market
players Table 4 15 - Requirement weights
Requirement Economic Time Environmental Safety Social
Weights 27 30 25 13 5
bull Weights of criteria
In cost and time of project which are single criteria have 100 of weights However for
instance in environmental and AHP method must be used to assign the weights based on the
importance in an environmental consideration The amount of emission that construction activities
can produce and the amount of negative effect on the global environment have been considered for
AHP method in weight assignment process Energy consumption and material consumption have the
priority to consider in LFA analysis because the consumption of primary resources have to be
minimized in a project at the first step and then the emission have to be reduced by changing the
processes etc Finally the ability to re-use and recycle and elements must be improved (Mohammad
Kamali 2017) (John Quale 2012) (Marta Gangolells 2014) Therefore Energy Consumption and
Material consumption have the most weight of 17 Embodied energy with 16 and waste generation
Greenhouse Gas emission and Recycle achieved 15 of weight At last noise Pollution took the least
priority of weights with 5 Table 4 16 - Weights of criteria
bull Weights of Indicators
Both of Economic and Time indicators divided to two sub-categories project cost and time and
their stability ratios with 80 and 20 weights by AHP method
Criteria that are single indicator obviously have 100 of weights However there are two
indicators in recycle criteria Recyclability and Re-use of elements with 40 and 60 weight
respectively Moreover Embodied Energy have is divided to Embodied energy used which is more
CriteriaEnergy
consumption
Waste
generation
Material
Consumption
Noise
pollution
Greenhouse
gas emissionRecycle
Embodied
energy
Weights 17 15 17 5 15 15 16
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
74 | P a g e
important than the other that is saving in embodied energy by re-use because as it mentioned before
in the first place the use have to be minimized and then actions such as re-use of elements have to be
done 70 of weight for Embodied energy use and 30 for Saved Embodied energy are assigned Job
stability and New job creation with weights of 50 each are the Job status indicators (Figure 411)
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software
Value function play an important role on deciding which comparative final value can each
indicator have among the other indicators for each alternative To evaluate the sustainability index
(Is) of each alternative solution value functions assigned and were used (Alarcon et al 2011) The
generic form of a value function is represented by Table 417 which allows to assess the sustainability
(satisfaction) associated with each indicator by transforming the physical units to a dimensionless
value between 00 and 10
Equation 4 1 - Functionality of value function elements
In Eq (41) B is the value of indicator(Iind) for Xmin Xmin is the minimum abscissa value in the
indicator interval assessed X is the abscissa value for the indicator assessed Pi is a shape factor which
defines whether the curve is concave (Pi lt 1) convex (Pi gt 1) linear (Pi = 1) or S-shaped (Pi gt 1) (see
figure 412) Ci approximates the abscissa at the inflexion point Ki tends towards (Iind) at the inflexion
point B the factor that prevents the function from exceeding the range (0 1) is obtained by Eq (42)
Xmax being the abscissa value of the indicator that gives a response value of 1 for increasing value
functions
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
75 | P a g e
Equation 4 2 - B value equation
Figure 4 12 - Possible forms of the value function
Due to the lack of existence of resources for assigning the specific value functions for modular
alternatives some hypotheses that can increase the feasibility and sustainability of project were
considered for the shape P K and C values to select the best form of abacus
In the other side maximum and minimum satisfaction points were selected on the
expectations of a project management view For instance in total project cost indicator case
minimum satisfaction point is 82000 AUD that is slightly more than the traditional reinforced concrete
alternative project cost (812298 AUD) because of the fact that those alternatives should be
considered as a reasonable options which can make saving in final budget Moreover the same rule
can be applied for maximum satisfaction point which is close to the Timber Modular alternative (45000
AUD) to minimize the final budget as much as possible The shape of the abacus was selected as
Convex shape (Convexa in MIVES) because even the least economic saving that an alternative can
achieve have a positive effect on the satisfaction of project and can be given any positive points in a
scale of ldquo0 to 10rdquo But the more the curve closes to the traditional alternative budget the les
satisfaction it can receive (Figure 413)
Figure 4 13 - Value function for total project cost in MIVES
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
76 | P a g e
The following Table 417 includes the value functions which were used for the rest of the
indicators Table 4 17 - Value function for indicators in MIVES
Data analysis
Indicators Values
Indicator data were translated to general normalized values shown in Table 418 amp 419 based
on the given value functions that earlier assigned This step is crucial for next analyses which will be
done to result the criteria and requirement values which lead to sustainability Indexes that can take
the multi-criteria decision As it can be seen these values have the same range of 0 to 1 so that can be
compared in with a common unit Comparisons are obvious in this level because of single value
orientation of each indicator however on following analysis there will be multi-criteria comparisons
which can achieve useful data for future decision-making process Table 4 18 - Indicators normalized values
Table 4 19 ndash Indicator normalized values
Indicators Lower limit Upper limit Max satisfaction Min satisfaction P K C Shape
Total Project Cost 30000 90000 43000 82000 05 05 79900 Concave
Cost stability 0 10 10 5 05 05 55 Concave
Total Project Time 20 75 20 68 05 05 632 Concave
Time stability 0 10 10 5 05 05 55 Concave
Energy Utilized 75 220 80 205 05 05 1925 Concave
Solid Waste 0 100 0 18 08 05 162 Concave
Material Consum 10000 70000 12000 63000 05 05 57900 Concave
Noise Level 58 78 62 72 05 05 71 Concave
CO2 32000 60000 32000 55000 05 05 52700 Concave
Recyclability 0 10 10 0 05 05 1 Concave
Re-use 0 100 60 0 05 05 20 Concave
Embodied energy 600 950 600 915 05 05 8835 Concave
Embodied saved 0 100 90 30 05 05 36 Concave
Injury risk 0 4 155 22 05 05 2135 Concave
Protection level 0 10 10 0 1 001 1 Lineal
Job stability 0 10 9 4 1 001 45 Lineal
New job creation 0 10 10 0 05 05 5 Concave
Quality Satisfaction 0 10 10 0 1 001 5 Lineal
R1C1I1 R1C1I2 R2C1I1 R2C1I2 R3C1I1 R3C2I1 R3C3I1 R3C4I1 R3C5I1
TRC 016 051 024 051 027 029 01 034 092
PSM 094 092 098 092 098 082 099 088 023
PCM 09 081 097 081 097 059 093 088 065
PTM 098 092 1 092 1 064 097 088 085
R3C6I1 R3C6I2 R3C7I1 R3C7I2 R4C1I1 R4C2I1 R5C1I1 R5C1I2 R5C2I1
TRC 073 026 1 024 024 021 02 063 05
PSM 095 094 023 095 094 09 08 092 09
PCM 092 068 064 077 094 09 08 092 08
PTM 098 084 092 085 094 09 08 092 09
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
77 | P a g e
Criteria Values
MIVES analysed each criterion by single or multi-indicator normalized values and resulted
values with a same range of 0 to 1 for following comparisons Table 4 20 - Criteria normalized values
Table 4 21 - Criteria normalized values
To begin with Project Cost (R1C1) criteria values shows that Almost three modular
alternatives performed 3 times more than the traditional method positively caused by hugely less total
project cost (R1C1I1) and great cost stability (R1C1I2) in project final budget The minimum value
belongs to PTM with 097 and slightly more than PSM and PCM is the next alternative with a value of
088 and at last TRC with 023 (Figure 414)
Figure 4 14 - Criteria normalized values
The comparison between modular alternatives in terms of which one can save time on the
schedule is close and it can be said that all three can make the project executed more than 3 times
shorter than traditional approach Timber steel and concrete options with respectively 098 097 and
094 values were compared to the conventional concrete method with 029 value (Figure 415)
R1C1 R2C1 R3C1 R3C2 R3C3 R3C4
TRC 023 029 028 029 009 032
PSM 094 097 099 083 099 088
PCM 088 094 096 059 094 088
PTM 097 098 101 064 096 088
R3C5 R3C6 R3C7 R4C1 R4C2 R5C1 R5C2
TRC 091 045 083 024 021 040 052
PSM 024 096 048 095 090 088 092
PCM 064 077 072 095 090 088 080
PTM 085 091 096 095 090 088 092
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
78 | P a g e
Figure 4 15 - Project Schedule
ldquoEnergy saving potentialrdquo in modular methods are close to the maximum satisfaction point
with timber solution and steel modules while concrete option is on the chase with 096 While
Traditional alternative only have 28 of satisfaction level
ldquoWaste generationrdquo among the alternatives have a different attitude while traditional method
with value of 029 has the most ratio of material waste production modular alternatives are
performing better where steel option have the most reduction with value of 083 and follow to that
timber and concrete options respectively 064 and 054 values PCM alternative as it said before
because of similarity of material choice to TRC have the minimum performance among the other
three (Figure 416)
Figure 4 16 - Waste generation ratios
ldquoMaterial consumptionrdquo criteria are dominated by modular methods which have a high
satisfaction with over than 09 normalized values while TRC performance can be concerning for the
primary resources with 01 normalized value
Previously on this report the fact was mentioned that off-site construction can benefit the
environment with noise reduction during construction activities based on literatures and this study
confirms this advantage by 088 values of all three modular alternatives and 032 value of traditional
RC which is less than half of modular options
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
79 | P a g e
A highlight of this study is about the comparison of CO2 Emissions of alternatives during the
constructionfabrication activities which traditional method have the minimum contamination with a
value of 091 and follow to that Timber option with 085 which is close to the TRC method Later to
that Concrete modules have a value of 064 and the minimum satisfaction belongs to the steel
modules with 024 normalized value This result bring uncertainty to the fact that modular
construction can reduce the Greenhouse gas emission to 30 over the literature review
Figure 4 17 - CO2 Emission normalized values
This study shows that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options with a value of 096 because of the material choice
repetition in element manufacturing and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution have 091 value that can confirm the concept of
recyclability for wooden modules which was mentioned by participants in professional survey as well
Figure 4 18 - Recyclability and re-use potential of alternatives
There is a discussion about the amount of embodied energy used during the lifetime of each
alternative and the potential of future saving by re-use of elements in projects which effect the total
embodied energy consumption in construction
As the Figure 419 explains traditional method has the maximum satisfaction level in terms
of consumption while steel modules have the least satisfaction of life cycle embodied energy used of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
80 | P a g e
023 PTM have a better value of 091 which shows that Timber solution can be reliable among the
others
However this study resulted that the most re-use value belongs to steel option with 095
value that and other two timber and concrete modules respectively with 085 and 077 can
compensate the gap with traditional method that has only 024 Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction total value of 096 Later
traditional reinforced concrete method with 088 still proves its abilities over other two modular
alternatives
Figure 4 19 - Embodied energy consumption and saving potential by reuse
In terms of safety modular alternatives because of their off-site nature can provide a high
satisfaction level with values of 095 in injury risks for workers and 090 protection from nature causes
which confirms the theory of safety advantage of modular construction over traditional methods from
literature studies (Figure 420)
Figure 4 20 - Safety advantage of modular construction over traditional method
Social benefits which were mentioned in literature review section also had been examined in MIVES
system and the job stability and job creation in modular construction can benefits the construction
society in significant way among the regions that have employability ratio problem
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
81 | P a g e
Figure 4 21 - Social criteria
Requirement Values
After analysis on criteria functions general values of each requirement were related to
alternatives achieved which can examinate all four construction methods to know which option is
more suitable in terms of Economic time environmental safety and social issues
The Table 422 below demonstrates the Requirements normalized values for each alternative Table 4 22 - Requirement normalized values for four indicators
bull Economic and Time requirements
As the graph illustrates Modular methods have a significant performance in economic and
time terms with the maximum values of 097 and 094 in Time and 098 and o97 in Economic
requirement for Timber and then Steel modules-based methods respectively Traditional reinforced
concrete option showed a poor functionality in cost and time of project with minimum values of o29
and 023 in order (Figure 422)
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values analysed by MIVES
Requirements Economic Time Environmental Safety Social
TRC 023 029 045 022 046
PSM 094 097 075 093 088
PCM 088 094 078 093 084
PTM 097 098 088 093 088
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
82 | P a g e
bull Environmental requirement
Generally all three modular approaches have beaten the traditional method with almost
double of normalized values in comparison
Despite the poor performance of steel modules in Greenhouse gas emissions and Embodied
Energy used in construction in total numbers proved that can provide the environmental demands
better than traditional option with a value of 075 which is third modular alternative in overall
Prefabricated Timber modules obtained the maximum value of 088 which claims not only
most economic option but environmentally friendly among other relatives and following to that
Concrete modules with value of 078 shows its liability to be chosen in case of need while the
traditional concrete method which includes most of the used materials n PCM but in a on-site plant
only can achieve a satisfaction value of 045 among the others (Figure 423)
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind
bull Safety and social requirements
The dominance of Modular construction in safety and social requirements over conventional
option can be seen in Figure 424 which can raise the possibility of modular methods to be the best
decision over the traditional option to construct this residential project As it was mentioned before
these two criteria must be considered in any decision-making process because of their high
importance in construction industry
Figure 4 24 - Modular dominance in safety and social requirements over conventional option
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
83 | P a g e
Sustainability Values (Final decision)
Finally the sustainability Indexes can be obtained to claim which alternative will be decided
as the most sustainable option for the main studyrsquos project to be build The needs of market such as
short project schedule cheaper budget reduction in environment emissions and ability to
recyclereuse safety measures and social benefits put effects on this decision as previously
mentioned
Table 423 explains that Prefabricated Timber Modules (PTM) is most sustainable alternative
among the other with a perfect normalized value of 094This could be because of its shorter schedule
of construction lowest total budget and excellency in environmental performance among the other
alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative Table 4 23 - SI (Sustainability Indexes related to four alternatives)
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This fact explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives
TRC PSM PCM PTM
SI 032 090 088 094
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
84 | P a g e
5 Conclusions Decision making process
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria etc However to find out how much practical these benefits are in the market several trade-
offs must be done by professional tools such as project management software programs which can
take decisions based on the input data that receive MIVES software was used in this study to
examinate these benefits The resources for this type of studies are limited due to the lack of focus or
newfound nature of this subject and only five of them were selected because of their variety of their
criterion studies reliability and accuracy of data Requirements criteria indicators and weights that
were used in MIVES had been selected based on demands of market and professional opinions
received from the survey and availability of data over references After assigning the value functions
which are related to satisfaction level on each criterion (For instance cost reduction time saving and
minimization of emissions) normalized values were achieved that can be compared between
alternatives with range of 0 to 1
Conclusions and discussion
ECONOMIC ndash TIME discussion
bull Decision-making result
Generally all three modular alternatives have beaten the traditional method with almost
double of normalized values Modular methods had a significant performance in economic and time
terms with the maximum values in Time and Economic requirements for Timber and then Steel
modules Traditional reinforced concrete option showed a poor functionality in cost and time of
project with minimum values
Literature reviews information
These Results confirm the 50 of time saving in projectrsquos schedule (McKinsey amp Company
report 2019) and 20 of cost reduction on the budget which was mentioned also in numbers of
literatures
Professional survey confirmation
In addition the claims from professional participants in survey about the 50 cost reduction
due to the added value of every hour of work in comparison with traditional stick and build on-site
method can be approved even far more those expectations
ENVIRONMENTAL discussion
bull Recyclability and re-use potential
This study showed that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options because of the material choice repetition of
elements in manufacturing line and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution can confirm the concept of recyclability for wooden
modules which was mentioned by participants in professional survey as well
bull Embodied energy used and saving by re-use
There is a discussion over the literature and survey participants about the amount of
embodied energy used during the lifetime of each alternative and the potential of future saving by re-
use of elements in projects which effect the total embodied energy consumption in construction
where one of the companies acclaims that ldquoour homes are not positive in energy consumption
aspectrdquo Traditional method has the maximum satisfaction level in terms of consumption while steel
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
85 | P a g e
modules have the least satisfaction of life cycle embodied energy used PTM have a better value of
091 which shows that Timber solution can be reliable among the others However this study resulted
that the most re-use value belongs to steel option and other two timber and concrete modules
respectively can compensate the gap with traditional method Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction Later traditional reinforced
concrete method still proves its abilities over other two modular alternatives
bull Greenhouse gas emission
Despite the poor performance of steel modules (PSM) in Greenhouse gas emissions that bring
uncertainty to the fact that modular construction can reduce the Greenhouse gas emission to 30
over the literature review and Embodied Energy used in construction proved that can provide the
environmental demands better than traditional option which is third modular alternative in overall
comparison
bull Most environmentally friendly alternative
Prefabricated Timber modules obtained the maximum value which achieves not only most
economic option but environmentally friendly among other relatives Following to that Concrete
modules shows its liability to be chosen in case of need while the traditional concrete method which
includes most of the used materials of PCM but in an on-site plant only can achieve the minimum
value
Comparison with literature review information and survey outputs
This comparison explains the truth about the concept of being environmentally friendly about
modular construction that have been mentioned in various scientific articles (McKinsey amp Company
report 2019) (M Kamali 2016) and the survey results which confirmed the concept in real cases at
the market over years of experience
SAFETY AND SOCIAL dominance by modular methods
The dominance of Modular construction in safety and social requirements over conventional
option was resulted which can raise the possibility of modular methods to be the best decision over
the traditional option to construct this residential project As it was mentioned before these two
criteria must be considered in any decision-making process because of their high importance in
construction industry Social benefits which were mentioned in literature review section also had been
examined in MIVES system and the job stability and job creation in modular construction can benefits
the construction society in significant way among the regions that have employability ratio problem
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES
Prefabricated Timber Modules (PTM) is most sustainable alternative among the other with a
perfect normalized value of 094This could be because of its shorter schedule of construction lowest
total budget and excellency in environmental performance among the other alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This result explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
86 | P a g e
Effective external factors on decision
The decision was made for the best alternative in terms of sustainability for a specific
residential case located in Sydney Australia among three modular options and one traditional
method However there are factors which can affect the final decision obviously Such as the location
of the project which the availability of primary resources can change the or alternatives or number of
indicators The local market and their demands for specific products can be crucial for choosing the
best method which affect the priorities of weights Regulation of every regions as it was mentioned
before can change the project requirements and indicators
The type of the project was a residential building that has its own characteristics but for
instance a school or hospital project would demand a higher functionality and lifetime because of their
distinctive operation kind and evidentially can be considerable in decision-making process to the end
step Special project due to their unique requirements often do not consider all criterions For
instance emergency health stations demanded during the Virus pandemic period have their own
material choose design enhancement and priorities on requirements
Future studies
Due to novelty of this subject there are numbers of studies still remained without coverage
which might be studied in future
Decision making study on two real projects with the input data of professional
modular and traditional constructors
Due to the lack of information over literature there were so many elements that have been
estimated by hypothesis and survey information therefore it is crucial to find these data in order to
do a precise study with real numbers These data can be obtained by requests to industry players to
have access of real project details including budget schedule material consumptions etc By this
action the liability of the study can be improved and accurate results can be achieved Thus a
decision-making process can be done to find out which alternative can be more sustainable
Technological studies about the production line of a modular off-site plant by factory
and on-site visits
There are still uncertainties about the status of use of automation productivity rate etc which
have to be analysed closely Modular construction was suggested as an example of industrialization in
construction industry to improve the productivity rate but corresponding to past survey the majority
of constructors are not benefiting from automation in their production lines and assembly processes
A study is needed on different phases of a project that have to be monitored and analysed scientifically
in order to find challenges errors and possible solutions to make this method even more sustainable
A survey about challenges in modular construction and its possible solutions to find
adequate solutions
Challenges have to focused more on this method because its players are still suffering from
the incompatibility of construction industry and the projectrsquos old conditions with innovative solutions
Series of interviews with experts factory visits etc have to be done to hear the voices of them and
then researchers to find solutions to update the industry and help them for growth
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
87 | P a g e
Recommendations
Cooperation between industrial players and scientific researchers in offsite
construction
Numbers of contrasts where found in the data and results among literatures professional
participants of survey and the decision-making study which shows a poor status of cooperation
between scientific researchers and professional players in the construction industry It is obvious that
the real data from the constructors designers etc in real projects are more reliable than scientific
estimation which in this case were based on BIM models and approximate calculations without any
interruption effects of common challenges in industry There were few participants who did not want
to share their project details in public or even education purposes or in a case one of the most
innovative players in modular industry responded their lack of available time to respond the survey
by direct email These attitudes can increase the gap between two vital elements for improvement
which are science and industry in construction society and to reduce it cooperation must be increased
specially in off-site society
Education about industrialization in construction and its alternatives
The idea of lack of education among engineers and architects who enter the professional
society about off-site construction methods was proved by the collected information from survey
participants which can cause problems in the projectrsquos design coordination and execution processes
These series of errors must be resolved by updating the education resources about innovative
methods such as off-site construction industrialization in construction concept rather than traditional
on-site methods that still occupy most of the educational courses these actions can improve the
common challenges in construction industry such as productivity problem and sustainability rate by
encouraging the researchers even far beyond the boundaries of investigations and make the way
possible to find more innovative solutions such as robotic fabrication 3D concrete printing etc
Establishing international and regional adequate codes
Use of automation is suggested by the researchers and industry players to raise the
productivity and sustainability in construction as the other industries which resulted positively
However constructors and manufacturers are suffering from a lack of exitance of international united
codding for their production line and boundaries and uncertainties by local regulations
To resolve these issues participants addressed an international code similar to what on-site
traditional methods have which the responsibility of creation of these codes are on the shoulders of
researchers and professional experts with a mutual partnership that is only possible with cooperation
of industry with science as it mentioned before
Synchronizing the contract conditions with modular construction conditions
There are numbers of problems in terms of contract conditions such as misunderstanding by
final client who is the end home buyer who ldquobelieves the factory to be the builder and the actual
independent builder to be a sales agent for the factoryrdquo one of the participants mentioned A
recommended solution for this problem is to define the relationships between the participants of
projects their responsibilities For instance requiring the builders customer to sign a disclosure
acknowledgement from that describes the relationship in detail In addition there is a lack of quality
partners on site The problem starts when on-site participants realize the advantages of modular
construction they tend to increase their prices for services which can increase the final prices of
project Another challenge which modular projects can face is the lack of delivery of project on agreed
time with an unacceptable quality of on-site execution The professionals answered that the
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
88 | P a g e
responsibility of ensuring that the work is done properly belongs to the builder which any ldquodelays in
this can result in postponed transport of product and interest through demurrage chargesrdquo
These problems must be solved by defining unique types of contracts that are adapted with
the off-stie construction nature and be obeyed by all the participants globally
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc
The only value that the market considers choosing modular method over traditional
construction is to be cheaper while majority of people the media and even professional engineers do
not understand the capabilities of modular construction Many people continue to confuse this form
of construction with HUD on frame products Another wrong perception that the publicmarket
believes is that the prefabrication methods limits the design options while some players believe that
the reverse is the case Therefore by using one of the main advantages of modular construction which
is shorter schedule the market can be dominated by modular projects and the more cases they
deliver the more recognised this method would be among the public and at the end the superior
nature of modular approach can be proved Another solution is a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Many of these wrong perception and misunderstandings can be
clarified by well-organized advertisements about several advantages that modular construction have
in comparison with conventional methods
Changes in financial strategies and adapting them with off-site construction nature
Financial assists which are crucial for kind of projects that are dependent to these aids are
not harmonized with modular project processes where there are argues that until the first deliveries
of elements to the site location and their assembly these aids will not be reachable This issue creates
pressure on cash flow of project where bank finance is involved Changes in contract conditions and
education for financial supporters are recommended solutions to improve the partnerships in
projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
89 | P a g e
6 References 1) Balasbaneh AT Ramli MZ A comparative life cycle assessment (LCA) of concrete and
steel-prefabricated prefinished volumetric construction structures in Malaysia Environ Sci
Pollute Res (2020) httpsdoiorg101007s11356-020-10141-3
2) Doran D and Giannakis M (2011) An examination of a modular supply chain a
construction sector perspective Supply Chain Management Vol 16 No 4 pp 260-
270 httpsdoiorg10110813598541111139071
3) Lawson RM Ogden RG Bergin R 2012 Application of modular construction in high-rise
buildings Journal of Architectural Engineering httpsdoi101061(ASCE)AE1943-
55680000057
4) Diez R et al (2007) lsquoAUTMOD3 The Integration of Design and Planning Tools for Automatic
Modular Constructionrsquo International Journal of Advanced Robotic Systems httpsdoi
1057725671
5) Lee J Park M Lee H ampamp Hyun H (2019) Classification of Modular Building
Construction Projects Based on Schedule-Driven Approach Journal of Construction
Engineering and Management 145(5) 04019031 httpsdoi101061(asce)co1943-
78620001656
6) Barbosa F Woetzel J Mischke J Ribeirinho M Sridhar M Parsons M Brown S
(2018 July 09) Reinventing construction through a productivity revolution Retrieved
September 28 2020 from httpswwwmckinseycomindustriescapital-projects-and-
infrastructureour-insightsreinventing-construction-through-a-productivity-revolution
7) Quale J Eckelman MJ Williams KW Sloditskie G and Zimmerman JB (2012)
Construction Matters Comparing Environmental Impacts of Building Modular and
Conventional Homes in the United States Journal of Industrial Ecology 16 243-253
httpsdoi101111j1530-9290201100424x
8) Horwitz-Bennett Barbara (2020) Rising to the challenge sl Modular Building Institute
(MBI)
9) Lu N amp Korman TM (2010) Implementation of Building Information Modeling (BIM) in
Modular Construction Benefits and Challenges
10) Institute Modular Building 2019 Permanent Modular Construction Canada Modular
Building Institute
11) Josa A (2012) Introduccioacuten a MIVES y el anaacutelisis multicriterio Jornada sobre la Importancia
de un meacutetodo para la toma de decisiones modelo MIVES para una ingenieriacutea sostenible
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
90 | P a g e
12) Aye L Ngo T Crawford R H Gammampila R amp Mendis P (2012) Life cycle greenhouse
gas emissions and energy analysis of prefabricated reusable building modules Energy and
buildings 47 159-168
13) Kamali M amp Hewage K (2016) Life cycle performance of modular buildings A critical
review Renewable and sustainable energy reviews 62 1171-1183
14) Lawson M Ogden R Goodier C (2014) Design in Modular Construction London CRC
Press httpsdoiorg101201b16607
15) Generalova E M Generalov V P amp Kuznetsova A A (2016) Modular buildings in modern
construction Procedia engineering 153 167-172
16) Thompson J (2019) Modular Construction A Solution to Affordable Housing Challenges
Cornell Real Estate Review 17(1) 21
17) Modular construction for multifamily affordable housing (2018) WSP
httpscdnymawscomwwwnibsorgresourceresmgrosccepa-modular-construction-
forpdf
18) Hammad A W A amp Akbarnezhad A (2017) Modular vs conventional construction a
multi-criteria framework approach In ISARC Proceedings of the International Symposium on
Automation and Robotics in Construction (Vol 34) IAARC Publications
19) Ferdous W Bai Y Ngo T D Manalo A amp Mendis P (2019) New advancements
challenges and opportunities of multi-storey modular buildingsndashA state-of-the-art review
Engineering Structures 183 883-893
20) Bertram N Fuchs S Mischke J Palter R Strube G amp Woetzel J (2019) Modular
construction From projects to products McKinsey amp Company Capital Projects amp
Infrastructure 1-34
21) Hsu P Y Aurisicchio M amp Angeloudis P (2020) Optimal logistics planning for modular
construction using multi-stage stochastic programming Transportation Research Procedia
46 245-252
22) Rausch C Nahangi M Perreault M Haas C T amp West J (2017) Optimum assembly
planning for modular construction components Journal of computing in civil engineering
31(1) 04016039
23) Connor G Jones C E amp Finney S J (2014) Easing future low voltage congestion with an
AC chopper voltage regulator httpsdoi 101061(ASCE)CO1943-78620001001
24) Ahn Y H amp Kim K T (2014) Sustainability in modular design and construction a case
study of lsquoThe Stackrsquo International Journal of Sustainable Building Technology and Urban
Development 5(4) 250-259
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
91 | P a g e
25) Gunawardena D Mendis P Ngo D Aye L amp Alfano J (2014) Sustainable prefabricated
modular buildings httpsdoi 10131402148473920
26) Olearczyk J Al-Hussein M Bouferguene A amp Telyas A (2009) Virtual construction
automation for modular assembly operations In Construction Research Congress 2009
Building a Sustainable Future (pp 406-415)
27) Woźniak-Szpakiewicz E (2016) EU migrant crisis and increasing demand for modular
construction modular social housing complex for refugees in Munich In Back to the Sense
of the City International Monograph Book (pp 921-931) Centre de Poliacutetica de Sogravel i
Valoracions
28) Wunderlich-Malec 2019 The Modular Solution to Reduce Total Construction Costs
httpswwwslidesharenetJoelGil2wuderlich-malec-engineering-modular-construction
29) HAMMAD AWA AKBARNEZHAD A WU P WANG X and HADDAD A 2019 Building
information modelling-based framework to contrast conventional and modular construction
methods through selected sustainability factors Journal of Cleaner Production [en liacutenea] vol
228 pp 1264ndash1281 ISSN 0959-6526 DOI httpsdoiorg101016jjclepro201904150
Disponible en httpwwwsciencedirectcomsciencearticlepiiS0959652619312296
30) HONG J SHEN GQ LI Z ZHANG B and ZHANG W 2018 Barriers to promoting
prefabricated construction in China A costndashbenefit analysis Journal of Cleaner Production
[en liacutenea] vol 172 pp 649ndash660 ISSN 0959-6526 DOI
httpsdoiorg101016jjclepro201710171 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS0959652617324782
31) LOPEZ D and FROESE TM 2016 Analysis of Costs and Benefits of Panelized and Modular
Prefabricated Homes Procedia Engineering [en liacutenea] vol 145 pp 1291ndash1297 ISSN 1877-
7058 DOI httpsdoiorg101016jproeng201604166 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS1877705816301734
32) NEELAMKAVIL J 2009 Automation in the Prefab and Modular Construction Industry [en
liacutenea] Sl sn DOI 1022260ISARC20090018 Disponible en
httpwwwiaarcorgpublicationsproceedings_of_the_26th_isarcautomation_in_the_pref
ab_and_modular_construction_industryhtml
33) SANTIAGO M ALBERTO J MARIA NJ and PATRICIA G 2008 Building industrialization
robotized assembly of modular products En M ONORI (ed) Assembly Automation [en
liacutenea] vol 28 no 2 pp 134ndash142 ISSN 0144-5154 DOI 10110801445150810863716
Disponible en httpsdoiorg10110801445150810863716
34) McGeorge D amp Zou P X (2012) Construction management new directions John Wiley amp
Sons
35) Fieldwire (2018) Why the Construction Industry Is Stuck in the Past
httpswwwfieldwirecomblogis-construction-stuck-in-the-1960s
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
92 | P a g e
36) Construction industry - Office for National Statistics (2019) ONS
httpswwwonsgovukbusinessindustryandtradeconstructionindustry
37) Timmer M P O Mahony M amp Van Ark B (2007) EU KLEMS growth and productivity
accounts an overview International Productivity Monitor 14 71
38) Smith A (2011 September 22) Agile and Lean for Construction SlideshareNet
httpswwwslidesharenetadrianlsmithagile-and-lean-for-construction-9384237
39) The massive opportunity of digitization in Engineering amp Construction (2019)
JourneyappsCom httpsjourneyappscomblogmassive-opportunity-digitization-
engineering
40) Tapscott D amp Tapscott A (2018) Blockchain Revolution How the Technology Behind
Bitcoin and Other Cryptocurrencies Is Changing the World (Reprint ed) Portfolio
41) Can Blockchain Fix the Construction Industryrsquos Productivity Problem (2018) Enstoa
httpsenstoacomblogcan-blockchain-fix-construction-industrys-productivity-problem
42) Itanola M (2019 June 5) Hey Quantity Surveyor is BIM going to take your job Blaze
Threads httpswwwblazethreadcomhey-quantity-surveyor
43) BIM Community (2017) Remodeling Construction Industry with Digitization BIM and
Reality Capture httpswwwbimcommunitycomnewsload563remodeling-
construction-industry-with-digitization-bim-and-reality-capture
44) Kolarevic B (2003) Digital production Architecture in the digital age design and
manufacturing 38-63
45) Labonnote N Roslashnnquist A Manum B amp Ruumlther P (2016) Additive construction State-
of-the-art challenges and opportunities Automation in construction 72 347-366
46) Kapoutsis A C Chatzichristofis S A Doitsidis L de Sousa J B Pinto J Braga J amp
Kosmatopoulos E B (2016) Real-time adaptive multi-robot exploration with application to
underwater map construction Autonomous robots 40(6) 987-1015
47) Khoshnevis B (2004) Automated construction by contour craftingmdashrelated robotics and
information technologies Automation in construction 13(1) 5-19
48) R Alice (2019) CRYSTAL PALACE SHOWER TALK httpsbloginoxstylecomencrystal-
palace
49) Eba (2014) HISTORY ldquoballoon framingrdquo the first prefabricated building system (US)
Architecture for the 99 httpslikemyplacewordpresscom20140214history-balloon-
framing-the-first-prefabricated-building-system-us
50) Peter Goumlssel Arnt Cobbers Oliver Jahn (2012) A Brief History of Prefab ArchitectureWeek
httpwwwarchitectureweekcom20121003design_1-1html
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
93 | P a g e
51) Merin G (2018) AD Classics Habitat 67 Safdie Architects ArchDaily
httpswwwarchdailycom404803ad-classics-habitat-67-moshe-safdie
52) Sveiven M (2018) AD Classics Nakagin Capsule Tower Kisho Kurokawa ArchDaily
httpswwwarchdailycom110745ad-classics-nakagin-capsule-tower-kisho-kurokawa
53) Modular Building Experience | Deluxe Modular (2020)
httpswwwdeluxemodularcomexperience
54) Applications | Modular Construction | Bathroom Pods (2020) Howick Ltd
httpswwwhowickltdcomapplicationsmodular-constructionbathroom-pods
55) Project types (2018) Panel built httpswwwpanelbuiltcomblogmodular-building-types
56) Mobile Mini Merger - WillScot (nd) Willscot httpswwwwillscotcomAboutMobile-
Mini-Merger
57) Teague L (2017) Urbantainer breaks down the negative stereotypes of modular building
Frameweb httpsframewebcomarticleurbantainer-breaks-down-the-negative-
stereotypes-of-modular-building
58) Modular construction (nd) SteelconstructionInfo
httpswwwsteelconstructioninfoModular_construction
59) Modular V (2020) What Is Modular Building Construction Your Ultimate Guide Vanguard
httpsvanguardmodularcomabout-modular
60) Permanent Modular Construction Annual Report 2019 | Modular Building Institute (2019)
MBI httpswwwmodularorgHtmlPageaspxname=pmc-2019-home
61) Modular Construction Foundation (2020) Triumph Modular
httpswwwtriumphmodularcomabout-triumphour-servicesconstruction-
managementfoundations
62) Weights and Dimensions (2020) ITF httpswwwitf-oecdorgweights-and-dimensions
63) Sajip J (2019) Modular Construction A Sustainable Building Method NY-Engineers
httpswwwny-engineerscomblogmodular-construction-a-sustainable-building-
methodWeights and Dimensions (2020 August 28) ITF httpswwwitf-oecdorgweights-
and-dimensions
64) Muresan F (2019) What is Modular Construction NY-Engineers httpswwwny-
engineerscomblogwhat-is-modular-construction
65) ADVANTAGES of using SurePods prefabricated modular bathroom pods (nd) SurePods
httpswwwsurepodscomspeed
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
94 | P a g e
66) EasyPads - The easy-to-use foundation system for modular buildings (2019 March 23)
EasyPads - Foundation System httpseasypadscouk
67) Honrubia M amp Mendonccedila A (2019 June 18) The Benefits of Reusable and Modular
Constructions Ennomotive httpswwwennomotivecomreusable-modular-
constructions
68) Cosentino (2020) Discover Cosentino and all the characteristics of its materials
httpswwwcosentinocom
69) Al-Hussein M Manrique J D amp Mah D (2009) North Ridge CO2 analysis report
comparison between modular and on-site construction University of Alberta Canada
70) Vickers H (2017) Modular construction 4 health and safety benefits Building 4 Education
httpsb4edcomArticlefour-health-and-safety-benefits-of-modular-construction
71) PRISM (2020) HGA and The Boldt Company build STAAT ModTM critical care units to
address the COVID-19 hospital bed shortage PRISM Modular construction 4 health and
safety benefits Building 4 Education httpsb4edcomArticlefour-health-and-safety-
benefits-of-modular-construction
72) Harrouk C (2020 September 28) Mayor of London Launches Housing Design App to
Transform Construction ArchDaily httpswwwarchdailycomauthorchristele-harrouk
73) Schoenborn J (2012) A case study approach to identifying the constraints and barriers to
design innovation for modular construction (Doctoral dissertation Virginia Tech)
74) Casas prefabricadas inHAUS (nd) servicio post-venta casa modular archivos InHAUS
httpscasasinhauscomfranceestagservicio-post-venta-casa-modular
75) Catalunya U U P (nd) MIVES mdash Departamento de Ingenieriacutea Civil y Ambiental mdash UPC
Universitat Politegravecnica de Catalunya UPC httpsdecaupceduesproyectosmives
76) Kim D (2008) Preliminary Life Cycle Analysis of Modular and Conventional Housing in
Benton Harbor MI (Doctoral dissertation)
77) Gangolells M Casals M Forcada N amp Macarulla M (2014) Analysis of the
implementation of effective waste management practices in construction projects and sites
Resources conservation and recycling 93 99-111
78) Alarcon B Aguado A Manga R amp Josa A (2010) A Value Function for Assessing
Sustainability Application to Industrial Buildings Sustainability 3(1) 35ndash50
httpsdoi103390su3010035
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
95 | P a g e
Anexo 1
a) Indicators resources
o Prefabricated Steel Modular (PSM)
Table A1 1 ndash Cost of project PSM (Hammad 2019)
Table A1 2 -Time of project PSM (Hammad 2019)
Table A1 3 - Energy utilized during construction (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
96 | P a g e
Figure A1 1 - Injury risks for workers (Hammad 2019)
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
97 | P a g e
Figure A1 3 - Co2 amount (Aye 2011)
o Prefabricated Concrete Modular (PCM)
Figure A1 4 - Total project cost (Balasbaneh 2020)
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
98 | P a g e
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter)
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020)
o Prefabricated Timber Modular (PTM)
Figure A1 8 - Co2 emission (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
99 | P a g e
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
o Traditional Reinforced Concrete (TRC)
Table A1 6 6 - Projects cost (Hammad 2019)
Table A1 7 - Projects schedule (Hammad 2019
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
100 | P a g e
Table A1 8 - Energy utilised during construction process (Hammad 2019)
Figure A1 9 - Injury risks for workers (Hammad 2019)
Figure A1 10 - Noise level (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
101 | P a g e
Figure A1 11 - Greenhouse gas emission (Aye 2011)
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
102 | P a g e
Anexo 2 1 Survey Q amp A
Q How many years of experience do your company have in modular construction
industry Table A2 1 - Professional experience of the company
Company Responses
A 10-15
B 10-15
C 20-30
D 20-30
E 30-50
Q How many years of experience do you have in the modulartraditional construction
and what is your job position Table A2 2 - Personal experience of participant
Company Responses
A 15 years
B 13 years sales manager
C 30 years of which the last 25 have been as design architect
D Quantity Surveyor
E 3 years Foreign Trade Manager
Q What types of modules your company products in terms of material Table A2 3 - Type of modules
Company Responses
A Wood Steel
B Wood
C Wood
D Wood
E Counter and Fibber cabins Steel
Q Which types of projects you did so far Table A2 4 - Type f projects
Company Responses
A Residential houses
B Schools Residential houses Commercial buildings
C Residential houses
D Schools Residential houses Hospital Commercial buildings
E Schools Residential houses hospital Commercial buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
103 | P a g e
Q Num of employees num of factories and num of modules build Table A2 5 - Characteristics of production range
Company Responses
A 80 employees 1 factory 200 modsyear
B 130 1 490
C 15
D 50 Employees 2 factories 80 build
E 250 employees 2 factories 100000 m2 prefabricated 5000 containers 1000 cabinets TURKEY
Q What was your motivation to choosework in modular construction Table A2 6 - Motivation for doing modular construction
Company Responses
A High demands in market and lack of provide Innovation
B Economic profit
C Environmental benefits High demands in market and lack of provide Innovation Shorter construction schedule due to need Economic profit
D Shorter construction schedule due to need Innovation
E Economic profit
Q Do you have sup-contracts for your panels or they had built in your factories what
is the reason for this decision Table A2 7 - Panel production conditions
Company Responses A build our own
B PE design and approvals fire suppression design and installation ceramic tile Energy Star design and inspection are all subcontracted
C All built in house in our own workshop We have developed our own unique systems which are not available elsewhere
D build in factory - programme cost
E
EPS isolated panels are produced in our factories The other are being purchased from domestic market Standard is EPS isolation and its fixed costs are lower because of quantity The others are not standard investment in production is not feasible
Q What is the level of automation technologies you use in off-site and on-site
production and assembly Table A2 8 - Level of automation
Company Responses
A Extraordinarily little today investing in this heavily this year want to get to 80
B 20
C Off-site 60 on site 20
D 20
E 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
104 | P a g e
Q Does A modular project have a smaller number of labours Less wages of salary off-
site and on-site due to specialization of workforce Does the more value added in
each hour of work can compensate Table A2 9 - Laboral status
Company Responses
A Fewer labour hours and at less cost per hour 1 hour in the factory is equal to 4 on site
B Prefabricated systems-built modular construction generally has a smaller on-site labour force for a shorter period
C Labour similar but more efficient working off site
D Yes (less no of workers and wages) - no need for special work force
E -
Q Do you have any case of recycle and reuse the structuralnon-structural elements in
your projects Table A2 10 - Recycle and Re-use
Company Responses
A Yes
B Yes
C No
D No
E Yes
Q Do you upgrade the modules with other environmentally friendly technologies such
as solar panels in your projects Please give us some examples Table A2 11 - Innovative technology integration
Company Responses
A Our homes are all self-powered only company in the world to be doing this
B
This factory allows for site installation of solar panels and other energy savings processes on site by the independent builderbuyer of our modular building materials Modular makes the most sense to be used by architects and builders with environmentally friendly tech
C
Modules (flat packed floor wall and roof components) are constructed of ply and highly insulated with non-petroleum-based insulation (recycled glass as a fibre) Solar panels fitted as an add on to completed building
D None yet not been asked
E Solar technology is YES
Q Automation in off-site production generates less or more waste of material There
are some argues about less waste generation in manual activities because of better
sense of material resistance by normal labour (wooden material for instance) Table A2 12 - Automation status on waste generation
Company Responses
A we are not automated yet but believe automation will be much more efficient use of materials
B In our experience as a custom modular manufacturer automation has a significant cost that may not be recoverable for many months if not years- millions of dollars in cost of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
105 | P a g e
components set up and training versus hourly wage and benefits of trained factory workers
C Waste is much reduced and a proportion of the waste is remanufactured to smaller items or sold on to handymen
D Would be less waste but we do not use much automation
E -
Q How much reduction does off-site modular construction has in generating ldquowasterdquo in
comparison with traditional construction methods Table A2 13 - Reduction of waste
Company Responses
A 70 less waste
B I am unable to provide an answer to this question
C
As we are timber people emissions are low regardless of construction methods Steel and concrete use are kept to a minimum and these are the high emission materials
D We are still working on our carbon footprint
E 15 less carbon emission
Q How much reduction has in ldquoenergy consumptionrdquo off-site in comparison with
conventional on-site construction What about during the operation phase Table A2 14 - Energy consumption status
Company Responses
A Our homes are not positive from an energy perspective
B
Energy consumption of a factory is known and relatively constant on a weekly monthly and annual basis The modular components for a two-box ranch style house require 3 workdays on our factory floor and 4 more days in final finish prior to shipment A competent and experienced modular builder can many times finish the entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-built house could require as much as 4 months for the same completion
C Not assessed but doubt there is much difference
D We are still working on our carbon footprint
E 30 energy saving
Q Did you deliver any projects for providing emergency services in Covid-19 period You
can mention the projects in the other section Table A2 15 - Delivery of projects in COVID-19 pandemic period
Company Responses
A No
B No
C No
D No
E Yes
Q Did you construct any projects for world aid organizations and charities You can
mention them in the other section
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
106 | P a g e
Table A2 16 - Aid organization project delivery
Company Responses
A No
B No
C No
D No
E Yes
Q Do you offer post-sale services to your clients Table A2 17 - Post-sale services to client
Company Responses
A Yes
B No
C Yes
D Yes
E Yes
Q How much was your initial costs estimate (Factory set up etc) How long was the
investmentrsquos payback period Table A2 18 - Initial costs
Company Responses
A 20 million Canadian dollar 5-year payback
B What costs Factory set up or cost of modular product sold to builders What about labour engineering transportations etchellip
C The business has been building up over decades so it is not possible to isolate specific costs
D -
E 15 million USD 5 years
Q Which factors can change the initial costs Table A2 19 - Effective factors on initial costs
Company Responses
A Level of automation Product types and production range Less sub-contracts Site location
B Design of modular building- ie roof system high wind heavy snow loads etchellip Product types and production range Site location
C Financing Level of automation Product types and production range Less sub-contracts
D Level of automation Product types and production range Site location
E Level of automation Product types and production range
Q Can component re-use building portability and the life cycle value of materials be
used as a strategy to ldquocompensaterdquo for higher initial construction costs Table A2 20 - Re-use effect on budget
Company Responses
A -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
107 | P a g e
B
We use many lumber cut-offs PVC drainpipes and conduit and dry wall pieces over many modular orders Unusable drywall shingle and PVC pieces are collected and sent out for recycling Wood is collected and recycled into mulch product or used for heating by others
C Not easily Our methods (flat pack) due not lend themselves to building portability
D -
E 50 years life span of the products
Q Which factors did you consider for choosing modular construction over traditional
method Table A2 21 - positive factors about modular construction to be chosen
Company Responses
A traditional construction is broken
B
Speed ease and cost of overall construction Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
C Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
D Transportation costs and boundaries Local salary wages
E Transportation costs and boundaries Local salary wages Environmentally friendly
Q Do use BIM in your projects what are the challenges in using BIM Table A2 22 - Use of BIM in projects
Company Responses
A 100 BIM from conceptual to finished models
B No
C No
D No
E No
Q What effects the production line can have on the design Are there any boundaries
on the architectural design Table A2 23 - Influence of production line on design
Company What effects the production line can have on the design Are there any boundaries on the architectural design
A No you just need to design with our subassemblies in mind
B This factory maximum module dimension capability is 15rsquo9
C Workshop prefabrication gives the architect far more design freedom
D Width of building for transport to make economically viable
E No
Q Is there any lack of knowledge from architects or design engineers in modular industry
about production line processes transportation limitations etc
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
108 | P a g e
Table A2 24 - Lack of knowledge among experts
Company Responses
A Yes
B No
C NA
D Yes
E Yes
Q How state transport regulation and approval can harm the projects in cost and time
Have you experience delays in your schedules because of those Table A2 25 - Transportation regulation effect on projects
Q Does the concept of transportable materials add extra costs on the project Do the
reduction of material waste and multiple discounts can ldquocompensate the lossrdquo Table A2 26 ndash Transportable material choice and its effects
Company
Does the concept of transportable materials add extra costs on the project Do the reduction of material waste and multiple discounts can ldquocompensate the lossrdquo
A Transportation costs are offset by speed of production and reduced financing costs for the project
B Not significantly
C See 26 The reverse applies
D No
E No
Q What are the difficulties in using automation in off-site production processes Table A2 27 - Challenges of using automation
Company Responses
A Codding Integration with advanced software
B Cost
C -
D Integration with advanced software
E Codding Cost Lower salaries of manual processes by labour
Company
How state transport regulation and approval can harm the projects in cost and time Have you experience delays in your schedules because of those
A Yes Some areas are slow to respond
B
Yes Some states in the US are more difficult to ship oversized and ldquosuper loadsrdquo through This adds both time and expense to the projects
C No Our company prefabricates and flat packs so all components are within or close to legal load limits
D No
E Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
109 | P a g e
Q Which problems exist in modular construction in terms of contracts What are the
solutions Table A2 28 - Contract condition in modular industry
Q What are the challenges in defining responsibilities among participants of a project
due to the changing most of the activities to precast solutions Table A2 29 - Participation status in modular projects
Company
What are the common errors than can harm the synchronization of productivity between off-site production transportation and on-site installation progress For instance less demands on-site caused
A Lack of quality partners on site that see the benefits of modular and therefore increase their pricing
B
The builder owns the responsibility to ensure that site work is done on time and correctly Delays in this can result in postponed transport of product and interest through demurrage charges
C Provided control is tight none
D -
E -
Q Considering all components are prefabricated offsite what is the role of an outside
general contractor Table A2 30 - Role of outside general constructor
Company Responses
A will always need some component of site work to complete the project
B
An outside general contractor is the independent builder The modular factory is a material vendor to the general contractor The general contractor is responsible for all site work and permits as well as storage- installation- and finish of the modular product forming the house or structure they are building
C We do not use outside general contractors All stages from earliest concept design to completed building are in house
Q How often advantageous changes must be done in the production line and what are
the challenges
Company Which problems exist in modular construction in terms of contracts What are the solutions
A Every state has a different building code need a universal code
B
In some cases the end home buyer believes the factory to be the builder and the actual independent builder to be a sales agent for the factory Our company addresses this through accuracy in the relationship described on our website and social media as well as requiring the builders customer to sign a disclosure acknowledgement from that describes the relationship in detail
C Banks do not recognise work done until it is erected on site This creates cash flow pressure where bank finance is involved
D -
E Delivery on time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
110 | P a g e
Table A2 31 - Changes in production line and its effects
Company Responses
A Slows down production
B This company incorporates changes to product materials or procedures between orders A change in process will not occur that affects only some of the components of an order
C Not sure I can answer that ion the space All means of production have advantages and challenges We have chosen methods and stick to them
Q Do you have sub-contracted players involved in your project for site preparation and
foundation phase etc why Table A2 32 - Site preparation status
Company Do you have sub-contracted players involved in your project for site preparation and foundation phase etc why
A Yes Because we are selling in many geographic areas we need local representation
B No This is the responsibility of our customer- the general contractorindependent builder
C Yes Under direct supervision Their equipment is expensive and not portable It makes sense to use local contractors for footings
D -
E Yes
Q If the onsite foundation is constructed by an outside general contractor are there
additional challenges at the interface in terms of a technology gap the equipment or
tools used the construction experience of workers or in scheduling and phasing of
construction Table A2 33 - Challenges with sub-contractors for site preparation phase
Q What are the wrong perceptions about modular products among market and public Table A2 34 - Wrong perceptions for modular products
Company What are the wrong perceptions about modular products among market and public
A that their only quality is being cheaper
B
In the USA many people the media and even professional engineers do not understand the capabilities of modular construction Many people continue to confuse this form of construction with HUD on frame products
C With our methods (flat pack) that prefabrication reduces the design options The reverse is the case
Company
If the onsite foundation is constructed by an outside general contractor are there additional challenges at the interface in terms of a technology gap the equipment or tools used the constructionhellip
A we need to educate most local subs on our process and reason for doing things a certain way
B Not that directly affects the factory
C No
D -
E -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
111 | P a g e
Q What strategies are taken among manufacturers to either improve the public
perception of modular construction or to promote its advantages to architects and
potential clients Table A2 35 - Solutions for wrong perceptions
Company
What strategies are taken among manufacturers to either improve the public perception of modular construction or to promote its advantages to architects and potential clients
A Going fast Proving the superior nature of our homes by getting more of them into the world
B
There is some cooperation between builders manufacturers architects and engineers to educate the public The national entity is the Modular Home Builders Association See httpswwwmodularhousingcom
C Nothing specific We advertise our advantages and it is enough
Q Any other challenges and recommended solutions for them that you want to add
please Table A2 36 - Recommendations
Company Responses
A -
B -
C The capital cost of equipment Specialised digital equipment is expensive making it difficult for small and medium companies to enter the market
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Dedication
To my brother Milad one of the best executive civil engineers that I have ever seen who was and will be my role model and inspiration in construction world
دنیای در من بخش الهام و الگو که ام دیده تاکنون که اجرایی عمران مهندسین بهترین از یکی میلاد برادرم به تقدیمبود خواهد و بوده ساز و ساخت
To my parents Professor Kiomars VeisKarami who is my inspiration to pursuit post-education to be an ideal professor like him Ashraf Ahmadi who cherished and supported me all the way I am thankful for all your favours
استاد یک تا است عالی تحصیلات پیگیری برای من بخش الهام که کرمی ویس کیومرث پروفسور مادرم و پدر هب شما لطف از کرد حمایت من از و داشت گرامی مرا زندگی طول تمام در که احمدی اشرف باشم او مانند آل ایده
سپاسگزارم
To dear my friends and classmates Ali Sasani loveable Sofia and genius Junior who always were next to me and will be in my heart
من کنار در همیشه که عزیز جونیور و داشتنی دوست وفیاس ساسانی علی عزیزم های همکلاسی و دوستان برایبود خواهند من قلب در و بودند
To my valuable professors specially Professor Pablo Alvarez Pujadas who guided me to direction that helped me to discover a new perspective of civil engineering that I always was looking for
A mis valiosos profesores en especial al profesor Pablo Alvarez Pujadas quien me guioacute
hacia una direccioacuten que me ayudoacute a descubrir una nueva perspectiva de la ingenieriacutea
civil que siempre estuve buscando
To my language teachers Mr Roozbeh Kargar who made me able to write this dissertation in the most academic way without any obstacles Ms Shafie and Ms Ismaili who shared their knowledge of Spanish to help me through the courses to achieve great marks and improve my knowledge
هیچ بدون روش ترین اکادمیک به را نامه پایان این بتوانم من شد باعث که کارگر روزبه استاد من زبان اساتید به به را خود اسپانیایی زبان دانش که اسماعیلی خانم سرکار و یشفیع خانم سرکار محترم اساتید بنویسم مانعی
بهبود را خود دانش و آورم بدست را عالی نمرات تا کنند کمک من به آموزشی های دوره در تا گذاشتند اشتراکبخشم
ایرانی باد زنده ایران باد زنده
28092020
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Abstract
During past century construction industry is suffering from a poor productivity rate in
comparison with the other industries To solve this problem the concept of industrialization in
construction was introduced which Modular construction is one of its methods with a not short
history However during past decade had changed its nature to be used for longer lifetime as
permanent uses
The purpose of this study is to identify the possible advantages and investigate on common
challenges related to modular construction industry in a project management perspective and intend
to find adequate solution for them The methodology of this study is a combination of quantitative
and qualitative based approaches
A multi-criterion decision-making software (MIVES) was used to measure the functionality of
advantages and their effect on final decision to use ether three modular alternatives (Steel timber
and concrete) or a traditional reinforced concrete method for building a residential project The results
showed that despite few poor performances in two environmental criteria (CO2 emission amount and
Embodied energy used during construction) in general all three modular alternatives had overcome
traditional option in every requirement where prefabricated timber modular method became the
most sustainable alternative This result can confirm the positive effect of modular construction
advantages and show its superior nature over conventional construction
In addition a qualitative online survey form was sent to modular players to confirm the
identified benefits discussion about common challenges and receive recommendations and solutions
to solve them The responds were collected from five companies with the average of 20 years of
experience in modular construction which illustrated that the advantages can be achieved in real
projects as well as the literature review and study cases on decision making process identified
On the other hand there are challenges remaining without resolution such as Lack of
partnership among participants of project conflicts by local codding in use of automation wrong
perceptions of market etc
The possible solutions could be creating an international code for modular products
advertisement on potential advantages of modular method in publicmarket updating the contract
condition and most important of all improving the cooperation between scientific investigators and
off-site industry to motivate and provide the researchers with more real data to prevent contrasts in
hypothesises and find more innovative solutions1
Keywords Sustainability Modular construction Embodied energy Prefabrication Lifecycle assessment (LCA) Building information modelling (BIM) MIVES Productivity rate Standardization
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table of Contents Table of Contents 2
1 Introduction 1
Motivations 1
Orientation of previous studies 1
Gap of knowledge 1
Objectives of the study 2
Survey among the professionals in the modular industry by Online Form 2
Decision-making among three modular methods and conventional option by MIVES 2
Limitations 2
Lack of existence of references related to the subject 2
Non-accessible information from companies and scientific articles 2
Obstacles caused by global lockdown during covid-19 pandemic 2
Organization of the thesis 3
2 State of the art 4
Productivity problem in construction industry 4
Status of productivity rate of construction industry among other industries 4
Reasons of poor productivity 6
Solutions for improvement 7
Brief on modular construction 10
History of modular construction 10
Types of modular product 15
Module architectural types 15
Module structure types 22
Types of modular buildings based on operation period 27
Common uses of modular buildings in the market 27
Construction phases 28
Literature review on possible advantages 31
Scheduling benefits 31
Economic benefits 34
Environmental Benefits 36
Health and security benefits 38
Social-Laboral benefits 39
Modular Construction role in COIVD-19 Pandemic 40
Review on common challenges 41
Initial costs 41
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Architectural challenges 43
Transportation challenges 44
Wrong perceptions among public and real estate market 45
Integration of advanced software 46
Redefining the contracts 46
Supply chain-transportation-onsite assembly management errors 47
3 Common challenges in modular construction industry by a survey 48
Methodology 48
Objective 48
Role of the researcher 48
Ethical considerations 48
Survey setting 48
Development of questionnaire 49
Participant profile 50
Experience amp professions 50
Data collection 51
General information 51
Economic issues 52
Environmental status 52
Social Benefits 53
Initial costs 54
Design limitations 55
Transportation Limitations 55
Project management challenges 56
Social challenges 57
Data analysis amp conclusions 57
Advantages 57
Challenges discussion 58
4 Decision making based on potential advantages among three modular alternatives and
conventional construction method in a project by MIVES software 60
Methodology 60
Objective 60
What is MIVES 60
Data collection process 60
Case Study references 60
Input data 65
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Final indicators 69
Weights 73
Data analysis 76
Indicators Values 76
Criteria Values 77
Requirement Values 81
Sustainability Values (Final decision) 83
5 Conclusions 84
Decision making process 84
Conclusions and discussion 84
ECONOMIC ndash TIME discussion 84
ENVIRONMENTAL discussion 84
SAFETY AND SOCIAL dominance by modular methods 85
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES 85
Effective external factors on decision 86
Future studies 86
Decision making study on two real projects with the input data of professional
modular and traditional constructors 86
Technological studies about the production line of a modular off-site plant by factory
and on-site visits 86
A survey about challenges in modular construction and its possible solutions to find
adequate solutions 86
Recommendations 87
Cooperation between industrial players and scientific researchers in offsite
construction 87
Education about industrialization in construction and its alternatives 87
Establishing international and regional adequate codes 87
Synchronizing the contract conditions with modular construction conditions 87
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc 88
Changes in financial strategies and adapting them with off-site construction nature 88
6 References 89
Anexo 1 95
Anexo 2 102
1 Survey Q amp A 102
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study 4
Figure 2 2 - UK productivity status (Office for National Statistics -ONS) 5
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS) 5
Figure 2 4 - Value added comparison among industries (ennovacom) 6
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom) 6
Figure 2 6 - Fragmentations between construction industry players and their various productivity
rates (McKinsey 2019) 7
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom) 8
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom) 9
Figure 2 9 - Digital construction organization (wwwbimcommunitycom) 9
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom) 10
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom) 11
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom) 11
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8
meters (modulartch) 12
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau) 13
Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
14
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom) 15
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom) 16
Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom) 17
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom) 17
Figure 2 20 - Production steps of floor cassette to walls and their attachment together
(wwwhowickltdcom) 18
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom) 19
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom) 19
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom) 20
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom) 20
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom) 21
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-
Malec (wmengcom) 21
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo) 22
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
23
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported
module (wwwsteelconstructioninfo) 24
Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the
lower levels (wwwsteelconstructioninfo) 25
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other
metals (vanguardmodularcom) 26
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma
Beton) 26
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction
report MBI 2019) 28
Figure 2 34 - Overlaps of phases in modular construction project 29
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom) 30
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method
(McKinsey amp Company 2019) 31
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom) 33
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom) 33
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes) 34
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom) 34
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk) 35
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images) 36
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site
(wwwcadoltocom) 37
Figure 2 44 - various layers of a module building unit including insulations
(wwwsteelconstructioninfo) 38
Figure 2 45 - Compartment floor at junction with external wall and compartment wall
(wwwsteelconstructioninfo) 39
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use
inside convention centres arenas and temporary structures Image courtesy of HGA and The Boldt
Company (prismpubcom) 40
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The
Boldt Company 40
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction
(archdailycom) 41
Figure 2 49 -Balance between Initial costs and Economical benefits 42
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects
(casasinhauscom) 46
Figure 2 51 - synchronization between supply chain transportation and on-site assembly 47
Figure 3 1 - Online office forms for survey use 49
Figure 3 2 - Questionnaire development 50
Figure 3 3 - Participants motivations to start a modular company 51
Figure 3 4 - Re-use potential 53
Figure 3 5 - Contribution in Covid19 epidemic 53
Figure 3 6 - Post sale services por future clients 54
Figure 3 7 - effective factors in initial investments for start-up companies 54
Figure 3 8 - Lack of knowledge among designers and engineers 55
Figure 3 9 - challenges of using automation in off-site plants 56
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study
(WAHammad 2019) 61
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and
conventional methods (Akbarnezhad 2019) 61
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020) 62
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017) 62
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad
2017) 63
Figure 4 6 - Architectural section of multi-residential building (Aye 2011) 63
Figure 4 7 - Structural elements used in modules (Aye 2011) 64
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012) 64
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES) 65
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM
alternatives 71
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software 74
Figure 4 12 - Possible forms of the value function 75
Figure 4 13 - Value function for total project cost in MIVES 75
Figure 4 14 - Criteria normalized values 77
Figure 4 15 - Project Schedule 78
Figure 4 16 - Waste generation ratios 78
Figure 4 17 - CO2 Emission normalized values 79
Figure 4 18 - Recyclability and re-use potential of alternatives 79
Figure 4 19 - Embodied energy consumption and saving potential by reuse 80
Figure 4 20 - Safety advantage of modular construction over traditional method 80
Figure 4 21 - Social criteria 81
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values
analysed by MIVES 81
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind 82
Figure 4 24 - Modular dominance in safety and social requirements over conventional option 82
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives 83
Figure A1 1 - Injury risks for workers (Hammad 2019) 96
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
96
Figure A1 3 - Co2 amount (Aye 2011) 97
Figure A1 4 - Total project cost (Balasbaneh 2020) 97
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
97
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter) 98
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020) 98
Figure A1 8 - Co2 emission (Aye 2011) 98
Figure A1 9 - Injury risks for workers (Hammad 2019) 100
Figure A1 10 - Noise level (Hammad 2019) 100
Figure A1 11 - Greenhouse gas emission (Aye 2011) 101
Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo) 23
Table 2 2 - Possible benefits in projects scheduling 32
Table 2 3 - Economic benefits in modular method 35
Table 2 4 - Environmental Benefits 37
Table 2 5 - Health and safety amp Social-Laboral advantages 39
Table 3 1 - Participantrsquos profiles 50
Table 4 1 - Requirement tree with all indicators which considered for decision making process 67
Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed
to be done on them 68
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other
studied 68
Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow) 68
Table 4 5 - Qualitative indicators 69
Table 4 6 - First hand data over literature 69
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow) 70
Table 4 8 - First hand data over literature 70
Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue) 70
Table 4 10 - First hand data over literature 70
Table 4 11 - Final indicators for PCM 72
Table 4 12 - TRC first-hand data over literatures 72
Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow) 72
Table 4 14 - Final Quantitative indicators used for decision making process 72
Table 4 15 - Requirement weights 73
Table 4 16 - Weights of criteria 73
Table 4 17 - Value function for indicators in MIVES 76
Table 4 18 - Indicators normalized values 76
Table 4 19 ndash Indicator normalized values 76
Table 4 20 - Criteria normalized values 77
Table 4 21 - Criteria normalized values 77
Table 4 22 - Requirement normalized values for four indicators 81
Table 4 23 - SI (Sustainability Indexes related to four alternatives) 83
Table A1 1 ndash Cost of project PSM (Hammad 2019) 95
Table A1 2 -Time of project PSM (Hammad 2019) 95
Table A1 3 - Energy utilized during construction (Hammad 2019) 95
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 96
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 99
Table A1 6 6 - Projects cost (Hammad 2019) 99
Table A1 7 - Projects schedule (Hammad 2019 99
Table A1 8 - Energy utilised during construction process (Hammad 2019) 100
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011) 101
Table A2 1 - Professional experience of the company 102
Table A2 2 - Personal experience of participant 102
Table A2 3 - Type of modules 102
Table A2 4 - Type f projects 102
Table A2 5 - Characteristics of production range 103
Table A2 6 - Motivation for doing modular construction 103
Table A2 7 - Panel production conditions 103
Table A2 8 - Level of automation 103
Table A2 9 - Laboral status 104
Table A2 10 - Recycle and Re-use 104
Table A2 11 - Innovative technology integration 104
Table A2 12 - Automation status on waste generation 104
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table A2 13 - Reduction of waste 105
Table A2 14 - Energy consumption status 105
Table A2 15 - Delivery of projects in COVID-19 pandemic period 105
Table A2 16 - Aid organization project delivery 106
Table A2 17 - Post-sale services to client 106
Table A2 18 - Initial costs 106
Table A2 19 - Effective factors on initial costs 106
Table A2 20 - Re-use effect on budget 106
Table A2 21 - positive factors about modular construction to be chosen 107
Table A2 22 - Use of BIM in projects 107
Table A2 23 - Influence of production line on design 107
Table A2 24 - Lack of knowledge among experts 108
Table A2 25 - Transportation regulation effect on projects 108
Table A2 26 ndash Transportable material choice and its effects 108
Table A2 27 - Challenges of using automation 108
Table A2 28 - Contract condition in modular industry 109
Table A2 29 - Participation status in modular projects 109
Table A2 30 - Role of outside general constructor 109
Table A2 31 - Changes in production line and its effects 110
Table A2 32 - Site preparation status 110
Table A2 33 - Challenges with sub-contractors for site preparation phase 110
Table A2 34 - Wrong perceptions for modular products 110
Table A2 35 - Solutions for wrong perceptions 111
Table A2 36 - Recommendations 111
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
1 | P a g e
1 Introduction
Motivations
Construction industry is suffering for a poor productivity problem during the past 60 years in
comparison with other industries and industrialization in construction was suggested by the
investigators to improving the construction performance by applying production technologies and
design standardized products to be built in off-site plants By searching over the off-site methods
modular construction was found which is benefiting its high sustainability and productivity in
comparison with traditional construction approaches
One of the motivations of these study is to study the advantages of modular construction in
order to demonstrate the superior nature of modular construction over traditional methods to be
presented as a reasonable solution for productivity problem the However there are various of
opinions and argues about the beneficiary of this method so that it was decided to analyse them more
deeply in construction management perspective and even get into contact with the industry for
professional confirmation
Another motivation of this study was to contribute to development of modular construction
and find what is holding it back from developing by discovering the challenges in the modular
construction industry and find possible solutions to help for growth
Orientation of previous studies
During past two decades fewer studies in comparison with other innovative methods have
focused on this subject to analyse this method in economic environmental and functional areas to
discover the benefits and make comparisons with traditional construction methods where possible
McKinsey amp company report on 2019 had general overview on its potential advantages challenges
and its ability to raise the productivity in construction processes while introducing the benefits by
making comparisons in projectrsquos schedule budget and environmental performance among modular
and traditional methods and finally shedding a light on dark side which are the obstacles of growth in
industry and then suggesting possible solutions for improvements In addition there are numbers of
articles focusing on the environmental performance of modular buildings by doing Lifecycle
assessment (LCA) analysis on emissions waste generations and consumption primary resources etc
(Mohammad Kamali and Kasun Hewage et al 2016)
On the other side there are studies that made comparisons between traditional and modular
methods of construction to build a specific project based on BIM models and professional data bases
which led to great results that showed numbers of advantages (AWA Hammad et al 2019) (L Aye
et al 2011) (Ali Tighnavard Balasbaneh at Springer-Verlag 2020)
Gap of knowledge
Taking into account of existent researches there is a gap of knowledge which leads to few
questions that still have remained without answer
bull Confirmation of these benefits that came from scientific researches by professional
players in the industry
bull Do these advantages effect the final decision to choose modular method over
conventional way
bull What are the needs of the market that could be as motivations to use modular
construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
2 | P a g e
bull What are the challenges in the industry in the professional point of view
bull Do the solutions that suggested by researchers can be applied in real projects What
are their professional solutions
Objectives of the study
The importance of this study is to resolve the mentioned questions by accomplishing the
studyrsquos objectives that are separated to be achieved by two methods which are qualitative and
quantitative
Survey among the professionals in the modular industry by Online Form
bull To confirmcorrect the data from literature reviews about benefits of modular
construction
bull Their motivations and reasons to choose modular method
bull What are the constraints and obstacles that they are facing
bull Recommendations and solutions for these problems
Decision-making among three modular methods and conventional option by MIVES
bull To discover the advantages in real study cases by comparisons between four
alternatives
bull To examinate the functionality of every alternative in several criterions
bull How much effective these benefits can be in the final decision based on the
requirements of market and their priorities
Limitations
Several obstacles were seen during the study that effected the methodology and input data
significantly Here are some examples
Lack of existence of references related to the subject
Because of the subjectrsquos novelty or less focus the quantity of references is not enough to
cover all the dimensions of study therefore few estimation hypothesis (that were proved by the
results at the end) and consultants with experts were used instead to provide the necessary
information In addition many of the scientific reports and articles were published few months or
even days before the studyrsquos conclusions so that it was decided to be used immediately to improve
the studyrsquos liability
Non-accessible information from companies and scientific articles
There are innovative companies that because of their privacy policies and protection of
innovation could not provide the necessary data about their projects by request even for academic
uses
On the other side scientific papers in some cases were protected and did not have open
access not even with educational access permissions as requests have been denied by the authors
Obstacles caused by global lockdown during covid-19 pandemic
One of the unpredicted challenges that happened during the study was the virus pandemic
that affected the world negatively and this study was not an exception From on-site project and off-
site factory visits interviews with experts in the industry etc were cancelled Numbers of regions went
to full shutdown including offices factories etc which resulted in reduction of participations in online
survey form as well Therefore it was decided to select five most suitable participants to be analysed
instead of planed massive quantity of results
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
3 | P a g e
Organization of the thesis
⎯ Chapter two state of the art explaining the productivity problem history types and
phases of modular construction and literature reviews on benefits and challenges
⎯ Chapter three The online survey among modular players in the industry
⎯ Chapter four MIVES multi-criteria decision-making approach
⎯ Chapter five Conclusions and findings
⎯ Chapter six Recommendations
⎯ Chapter seven references
⎯ Anexo A (Input data references)
⎯ Anexo B (Survey QampA) 2
Kewwords Sustainability Modular construction MIVES Productivity rate Prefabrication Lifecycle assessment (LCA)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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2 State of the art Productivity problem in construction industry
Status of productivity rate of construction industry among other industries
It has been decades that construction industry is far behind the other industries in terms of
productivity rates Attempts had been done by innovative players in the industry but still the
difference is too enormous which the demands for improvement are needed
Globally construction sector labour-productivity growth averaged 1 percent a year over the
past two decades compared with 28 percent for the total world economy and 36 percent for
manufacturing If construction productivity were to catch up with the total economy the industryrsquos
value added could rise by $16 trillion a year (McKinsey 2019)
It can be said that the building industry is one of the key industries in the general economy
The construction sector typically comprises 8-10 of the Gross Domestic Profit (GDP) of a Western
economy (McGeorge amp Palmer 2002) Therefore only 10 improvement in construction
performance can represent a 25 increase in GDP (McGeorge amp Palmer 2002) Therefore there is
no doubt that improving productivity in the building industry will contribute positively to the general
economy
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
5 | P a g e
The UK has a problem with productivity and the construction sector has poorer productivity
growth rates than any other Simply put productivity is the amount of stuff (whether goods or
services) that is produced by a person in an amount of time UK productivity is lower than it was in
2008 and the construction industry has not seen any significant growth in productivity in the last 20
years (Figure 22)
Figure 2 2 - UK productivity status (Office for National Statistics -ONS)
Not all the regions are struggling at the same rate and the reasons which will be discused
furthermore can be the insterest of regulators to support innovations and new solutions which can
improve the productivity in construction industry(Figure 23)
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS)
The result is that between 70 and 90 of projects exceed the original planned cost and that
the overrun commonly varies between 50 and 100 of budget Construction also suffers from 57
of effort on non-value-added activities compared with 26 within manufacturing (Figure 24)
These productivity rates had experienced severalrises and downs in some periods which is
because of increase of demandas of housing that results a boost in construction industry in order to
provide the needs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 4 - Value added comparison among industries (ennovacom)
Reasons of poor productivity
There are numbers of reasons for this poor performance The industry is extensively
regulated very dependent on public-sector demand and highly cyclical Informality and sometimes
corruption distort the market Moreover poor project management and execution insufficient skills
inadequate design processes and underinvestment in skills development RampD and innovation can
affect the productivity indirectly by decreasing the feasibility and value of the activities and add extra
costs on the project
Another key factor that causes a disruption among construction players which reduces the
average productivity rate is the lack of harmony in productivity between the players In other words
The sector divides mainly in two large-scale players involved in heavy construction such as civil and
industrial work and large-scale housing and a large number of firms engaged in fragmented
specialized trades such as mechanical electrical and plumbing work that act as subcontractors or
work on smaller projects like refurbishing single-family housing The first group manages to have 20
to 40 percent higher productivity than the second However even in the more productive heavy
construction sector there are endemic-potentially structural-challenges in meeting cost and schedule
commitments on megaprojects and players routinely subcontract specialized trades (McKinsey amp
Company 2019) (Figure 26)
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
7 | P a g e
Figure 2 6 - Fragmentations between construction industry players and their various productivity rates (McKinsey 2019)
Solutions for improvement
Nowadays there are solutions which are being used in construction world such reshaping the
regulation rewiring the contractual framework to reshape industry dynamics rethink design and
engineering processes improve procurement and supply-chain management improve on-site
execution infuse digital technology new materials and advanced automation and reskill the
workforce Each region based on their capabilities potential and Infrastructures would take a decision
which ways can be applied to increase the productivity in construction projects in a short or long
period
bull Redefine regulation Actions include streamlining permitting and approvals processes as
Australia has done reducing informality and corruption and encouraging transparency on cost
and performance as the International Construction Measurement Standards project does Many
governments allocate grants for innovation and training Germanyrsquos Federal Ministry of Transport
and Digital Infrastructure (formerly the Federal Ministry of Transport Building and Urban
Development) for instance supports RampD through studies in building materials Best practice
regulation would include moving toward outcome-based more standardized building codes and
consolidating land to promote scale Examples include Singaporersquos move to allow cross-laminated
timber (CLT) for high-rise structures and Japanrsquos promotion of scale through land pooling
bull Re-arrange the contractual framework Establishing a ldquosingle source of truthrdquo on projects for
monitoring progress early potentially supported by collaborative technology helps to minimize
misalignments and enable joint corrective action The data already exist to fundamentally
improve the accuracy of cost and schedule estimates Where players continue to use traditional
contracts they should introduce incentives that significantly improve performance and alignment
not at a trade or package level but at the project-outcome level To move toward best practices
appropriate alternative contracting models such as integrated project delivery (IPD) help build
long-term collaborative relationships Relational contracts will need to become more prevalent
than transactional contracts Sufficient investments in up-front planning incorporating all partiesrsquo
input have been shown to raise productivity substantially Smart Contracts are another example
of these solutions which during recent years is being identified by the major players A smart
contract is a computer program or a transaction protocol respectively which is intended to
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
8 | P a g e
automatically execute control or document respectively legally relevant events and actions
according to the terms of a contract of an agreement or of a negotiation The objectives of smart
contracts are the reduction of need in trusted intermediators arbitrations and enforcement costs
fraud losses as well as the reduction of malicious and accidental exceptions (Tapscott Don
Tapscott Alex amp Savelyev Alexander 2016)
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom)
bull Off-site production shift The biggest impact on productivity would come from moving toward
thinking about construction as a production system where possible encouraging off-site
manufacture minimizing on-site construction through the extensive use of pre-cast
technology assembling panels in factories and then finishing units onsite
bull Improve on-site execution There are four key approaches that are well known in the industry
but have not been universally adopted First is the introduction of a rigorous planning process
the Last Plannerreg System (LPS) is a useful tool to ensure that key activities are achieved on
time and on budget The use of integrated planning tools on a large-scale oil and gas project
for instance achieved a 70 percent increase in the projectrsquos productivity Second is reshaping
the relationship and interactions between owners and contractors and key performance
indicators (KPIs) being agreed on and used at regular performance meetings at which on-site
issues are resolved Complementing commonly used KPIs with additional forward-looking plan
conformance metrics to identify and subsequently reduce variance is critical Third is
improving the mobilization for new projects by ensuring that all pre-work (for instance
obtaining approvals and developing project milestones) has been completed prior to starting
onsite Finally there is a need for careful planning and coordination of different disciplines
on-site along with the application of lean principles to reduce waste and variability On-site
productivity can be increased by as much as 50 percent by implementing a cloud-based
control tower that rapidly assembles accurate data in near real time that is both backward-
looking and predictive (for example using plan conformance and other variability and
inventory metrics)
bull Introduce digital technology advanced automation Companies can start by making 3D
building information modelling (BIM) universal within the company alongside use of digital
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
9 | P a g e
collaboration tools drones and unmanned aerial vehicles for scanning monitoring and
mapping They can put themselves at the cutting edge by using platforms such as 5D BIM to
establish transparency in design costing and progress visualization (Figure 28)
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom)
Advanced analytics enabled by the Internet of Things to improve on-site monitoring of
materials labour and equipment productivity and digital collaboration and mobility tools (such as
construction management apps loaded on mobile devices) to better track progress and collaborate in
real time (Figure 29)
Figure 2 9 - Digital construction organization (wwwbimcommunitycom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Advanced automated equipment and tools such as bricklaying and tiling robots can accelerate
on-site execution The field of digital fabrication (dfab) is quite broad and has many applications Dfab
techniques are based on the combination of computational design methods and automated
construction processes which are typically categorized as subtractive formative or additive
(Kolarevic 2003) The use of subtractive and formative digital fabrication is becoming mainstream in
the prefabrication (off-site) of building parts (eg by using laser cutting CNC milling etc)
In recent years additive fabrication processes especially 3D printing have experienced a
rapid development in many industries As interest in additive fabrication grows research into large-
scale processes begins to reveal potential applications in construction (Labonnote et al 2016)
Existing additive dfab technologies can be classified in two big clusters on-site and off-site
construction technologies On the one hand on-site digital fabrication aims to bring additive
fabrication processes on construction sites
Sousa et al (2016) classified on-site technologies in three main categories large scale robotic
structures mobile robotic arms and flying robotic vehicles A well-known example from first category
is Contour Crafting a robotic structure for 3D printing large-scale construction developed at the
University of Southern California (Khoshnevis 2004)
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom)
bull Reskill the workforce Change in the construction sector cannot be achieved without
investment in retooling a workforce that is aging and changing its makeup through migration
Construction firms and workers need to continuously reskill and train to use the latest
equipment and digital tools In the mix should be apprenticeship programs such as the one
run by Siemens in the United Kingdom training frontline workers in core skills that are
currently underdeveloped and increasing stability in the workforce by breaking seasonality
and cyclicality
Brief on modular construction
History of modular construction
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11 | P a g e
bull 1800s
In 1830 he first documented prefabricated home was created by London carpenter John
Manning for his son who was moving from England to Australia Manning built a prefabricated house
in pieces then shipped it to the Land Down Under for easy assembly In 1840 Modular construction
made its way to the United States in response to the housing needs of the California Gold Rush The
Crystal Palace was built for Britains Great Exhibition and remains one of the most famous examples
of early modular construction in 1851 Designed in less than two weeks it utilized light and
inexpensive materials such as iron wood and glass it was constructed in only a few months
Afterward the palace was dismantled moved and rebuilt at another location
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom)
bull 1900s
Augustine Taylor a builder in Chicago devised the balloon-frame method (Figure 212)
enabling walls to be built offsite then transported to the intended construction site for speedy
assembly The rise of catalogue houses happened Between 1908 and 1940 when Sears Roebuck and
Co sold more than 500000 prefab homes through its catalogue straight to consumers At the time
these houses cost less than two-thirds of conventionally built homes and many still exist throughout
the United States
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull WWII Housing Boom
Prefab structures continued into World War Two to meet the growing demand for mass
accommodations for military personnel So-called Quonset Huts or Nissen Huts in the UK
comprised of corrugated steel were introduced for domestic military and institutional uses
When soldiers began returning home in the United States there was a need for rapid
construction for new homes to accommodate these expanding families Once again modular
construction serviced those needs because of its efficiency reduced costs and quick construction
Today many of those units are still in use
bull Prefab in Post-war Europe
The situation in Europe was more difficult although millions of people had no place to live on
the Old Continent due to the destruction of the Second World War people were unwilling to accept
prefabricated construction In Germany which had not only lost 25 percent of its entire housing stock
to bombing but also had to integrate 12 million refugees from former German territories in Eastern
Europe one form of prefabricated housing was used extensively the Nissen Hut (similar to the
Quonset hut) An attempt was also made in post-war France to combat housing shortages with the
help of prefabricated houses In 1944 Jean Prouveacute was already commissioned by the Ministry of
Reconstruction and Urban Planning to build 800 houses as emergency shelters that could be easily
disassembled However only 400 of these Maisons agraveportique which were equipped with an axial
steel frame were ever erected Prouveacutes Alba houses developed for the Abbey Pierres homeless
organization in 1956 were also not a success (Peter Goumlssel Arnt Cobbers Oliver Jahn 2012
architectureweekcom)
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8 meters (modulartch)
bull The Pre-fabulous 60s
The 1960s were a period of social transition in which attitudes towards prefabricated housing
also changed During this era which was marked by space travel the moon landing and even childrens
books that predicted weekend trips to distant galaxies prefabricated construction was discovered both
as a form of artistic expression and as a technical means of creating houses to provide a basis for new
lifestyles which seemed to be imminent in a society characterized by an extremely optimistic view of
progress
These approaches supported the idea of creating megastructures out of residential capsules
the architect Moshe Safdie who was only 24 at the time presented his megastructure Habitat 67 at
the Expo 67 in Montreal 158 housing units consisting of 354 concrete modules assembled as a
conglomerate
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The British architectural group Archigram developed building structures made of residential
capsules as an architectural Utopia which could be expanded at will and joined to form entire cities
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau)
bull Eco-conscious 70s
In 1972 the Japanese architect Kisho Kurokawa built the Nakagin Capsule Tower in Tokyo
housing cells were layered around a prefabricated concrete core to form a fourteen-story residential
tower(Figure 215) The idea of residential capsule megastructures was repeatedly revived as in Zvi
Heckers Ramot housing development in Jerusalem in 1974
The ecology movement of the 1970s brought an end to this euphoria regarding technological
progress and futuristic architectural dreams Now highly modern building materials that did not seem
to be in harmony with a return to nature such as plastic or aluminium fell into disrepute A new
perspective of view replaced as a priority to choose the material types which have the minimum
relation with non-renewable resources
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
bull 90s
This was further exacerbated by the fact that prefabricated elements had often been used to
build high-density housing which was now generally viewed negatively Hence prefabricated building
now came to be associated with the aesthetic and social failure of deindividualized megalomaniac
prefabricated slab housing blocks clustered on the periphery of large cities Thus the acceptance of
the prefabricated house in large parts of Europe remained low up until the 1990s
Prefabricated construction only gradually began to again emancipate itself from a homespun
cheap mass-produced image during the 1990s This is mainly due to the use of computer-operated
programs in the design and production processes The prefabricated housing industry now stands at
a juncture reminiscent of the dynamism of the 1920s and 1930s
bull Modern days
For many years now companies like Muji in Japan or BoKlok in Scandinavia and more recently
also in Poland and England have been supplying prefabricated houses in large numbers In Sweden
alone with only nine million inhabitants 14000 units are sold every year Muji offers models designed
by Kengo Kuma and Kazuhiko Namba that are as simple as they are elegant and far more interesting
than the building-kit houses offered by the multinational concerns Mitsubishi Toyota and Panasonic
(deluxemodularcom 2019)
Countries around the world have enlisted prefab and modular construction methods for
decades For example an estimate of all detached homes that are prefabricated in each country
shows a potential for growth off 84 in Sweden 5 in the United States 9 in Germany 20 in the
Netherlands and 28 in Japan
Today prefabrication and modularization are utilized in the construction of hotels apartment
buildings offices hospitals and schools in every major US city Here is a rundown of the percentage
per industry of prefabricated structures that use some form of modular construction
(deluxemodularcom 2019)
bull 49 of healthcare facilities
bull 42 of college buildings and dorms
bull And 42 of manufacturing buildings
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Types of modular product
Module architectural types
The products can be categorized by its functions dimensions material or type of its operation
etc Here they will be introduced by their general characteristics
bull Bathroom pods
Bathroom pods are commonly used in the construction of most hotels and apartment
buildings these days and becoming used more for residential housing The main drivers for choosing
a modular pod method are
o The cost savings that can be made by building repeated designs in a factory
environment
o Higher quality finish
o Rapid installation
o No trades on site
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom)
Pod Construction Process can be various but the most common steps can be as below
(httpswwwhowickltdcom)
Once the bathroom specification has been finalized and the design completed the
machine files are issued and the framing can be produced
The frames are rolled out of the machine ready for assembly
The panels are assembled
The panels are then fitted with the internal boarding and finished with tiles or a
waterproof lining
The walls floor and roof are joined to create the room structure and the joints sealed
The fixtures and fittings can then be installed including
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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o Bath or shower
o Toilets
o Basins
o Lights
o Mirrors
o Cabinets
The plumbing and electrical components are connected
The pods are then subjected to an electrical test and a pressure test to ensure there
are no leaks (Figure 217)
The pods are then sealed to prevent access ready for transportation
Once on site the pods are slid into position and connected to the power and water services
This process greatly reduces the build time as there are no requirements for trades on the site As the
pods are sealed until the building is completed there are reduced chances of them being damaged
during the building construction phase
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom)
bull Kitchen pods
These pods are less common but are also becoming more frequently used All the appliances
and electrics can be fitted in the factory removing the need for work on site Kitchen pods are ideal
for renovating older or industrial buildings as all the electrical services for the building can be
integrated into the pod From student accommodation to residential flats modular kitchen pods are
suitable for a variety of different sectors and uses and because they are designed bespoke to each
clientrsquos exact specifications they can be anything from a fully fitted kitchen to a small kitchenette
Each modular unit is completely customisable from the worktops to the splashbacks and integrated
white goods
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Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom)
bull Volumetric and modular rooms
Volumetric and modular rooms are becoming widely used for buildings that have a repetitive
nature Common structures include
bull Hotels
bull Apartments
bull Student accommodation
bull Schools
bull Hospitals
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The benefits of being able to manufacture the complete unit in the factory (including the
bathrooms and fitting of furniture) are
o No weather delays
o Superior finish quality
o All the electrical and plumbing works are done in a controlled atmosphere
o The rooms are sealed before moving to site restricting unauthorized access
Modular rooms production process can be explained as below
Once the building design has been completed and the individual modules specified the
framing components can be made on a just in time basis for site delivery
A typical assembly process would consist of
The floor cassette is rolled and the flooring boards are attached along with the
required insulation and services
The wall and ceiling frames are assembled
The internal lining is fitted and painted
The wall frames are then attached to the floor cassette (Figure 220)
Figure 2 20 - Production steps of floor cassette to walls and their attachment together (wwwhowickltdcom)
The ceiling frames are then fitted
The bathroom can then be fitted and plumbed as well as the electrical fittings and
wiring
The wall and ceiling insulation is added to the frame
The fit-out can then be completed to the desired specification
A hotel module for example would feature carpets bed bedside furniture desk
wardrobe TV system air-conditioning (either vents from main system or stand-alone
unit) bathroom fittings and fixtures
Once completed the electrics are checked and the plumbing is pressure tested
A protective cover is then added for transport and the unit is delivered to site
On-site the units are craned into position and joined
The services are connected
The building is then roofed and clad to the required specification In some cases the cladding
can be fitted during the module assembly further reducing the on-site work
bull Modular Trailers
Outside of modular homes modular trailers are probably the type of modular building that
people are most familiar with These buildings have a lot of applications and are often used as a
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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temporary space solution These trailers can be relocated for several times and are well-equipped as
well Temporary pre-semester school classes and temporary offices can be two examples of these
trailers uses
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom)
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom)
bull Containers
When looking at modular containers they are structures that are typically used to contain a
shiprsquos cargo When Shipping containers were originally created they were designed with modularity
in mind They were required to withstand all kinds of abuse as they journey through some of the
worldrsquos harshest climates From salt water to freezing temperatures a shipping container is meant to
handle the worst of the worst while protecting some of the worldrsquos most precious cargo Comprised
of Corten steel it is in a shipping containers DNA to protect itself from any corrosion or rust and when
they fall off the ship they can take up to a week to sink With more boxes being imported than
exported we have an opportunity to reuse something that is desperately looking for a new home
There has been a shift recently where after these buildings serve their purpose as shipping containers
they are reused fitted with windows doors HVAC units etc And made into an office environment
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The biggest benefit of these containers is they are cheap very portable and easy to install on site
However since most of the time these buildings are retrofitted and remodelled into modular
buildings they usually do not have a lot of flexibility in layout or their dimensions
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom)
Shipping containers act as the exoskeleton of each module The original structure will frame
the HVAC wiring lighting plumbing appliances and wall finish materials Because containers were
built to be durable and mobile they can be transported by train tractor-trailer boat or in some cases
a powerful pickup truck Forklift pockets and corner castings allow the containers to be moved smaller
distances by crane and forklift Shipping containers empower you to move your modular structures
without sacrificing the structural integrity or damaging the modulersquos contents
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull Office Complexes
Office complexes will take several office modules and combine them to assemble a much
larger fully functioning office building Just like all modular construction these modules are
fabricated in a manufacturing environment except when these projects reach the job site they
function more similarly to a full-fledged construction site Generally the module will need a crane to
lift the section from the ground and place it in the correct spot to assemble the building Next the
workers will go through that module and do all things necessary to attach and hook up the piece
Then the next piece is put in place and these steps are repeated and again until the building is
finished
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom)
bull Modular enclosures
For instance one of the major electric utilities in the Northeast using Modular Construction is
Wunderlich Malec Integrated Control Enclosures since 2001 A standard 16times50times11-foot enclosure
with twenty (20) protective relay and control cabinets marshalling cabinets HVAC fire and security
completely installed wired and tested at the factory prior to shipment
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-Malec (wmengcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Module structure types
Modular structure types can be categorized by their materials or structural formation
o Steel Modules
bull 4-sided modules
In this form of construction modules are manufactured with four closed sides to create
cellular type spaces designed to transfer the combined vertical load of the modules above and in-
plane loads (due to wind action) through their longitudinal walls The cellular space provided is limited
by the transportation and installation requirements Depending on location and exposure to wind
action the height of buildings in fully modular construction is in the range of 6 to 10 storeys Modules
are manufactured from a series of 2D panels beginning with the floor cassette to which the four wall
panels and ceiling panel are attached generally by screws The walls transfer vertical loads and
therefore the longitudinal walls of the upper module are designed to sit on the walls of the module
below
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo)
It consists of a modular structure of high strength galvanized steel which is also used as the
basis for building closure Steel physical properties make it one of the most versatile materials for
construction since it is
ELASTIC Steel does not break as it has a great strength and elasticity It is easily workable and it has
a great advantage over traditional construction
RECYCLABLE Steel is 100 recyclable
DURABLE With zinc application it can become galvanized steel which has extraordinary durability
properties
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo)
bull Partially open-sided modules
4 sided modules can be designed with partially open sides by the introduction of corner and
intermediate posts and by using a stiff continuous edge beam in the floor cassette The maximum
width of opening is limited by the bending resistance and stiffness of the edge member in the floor
cassette Additional intermediate posts are usually square hollow sections (SHS) so that they can fit
within the wall width
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
24 | P a g e
bull Open sided (corner-supported) modules
Modules may be designed to provide fully open sides by transfer of loads through the
longitudinal edge beams to the corner posts The framework of the module is often in the form of hot
rolled steel members such as Square Hollow Section (SHS) columns and Parallel Flange Channel (PFC)
edge beams that are bolted together
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported module
(wwwsteelconstructioninfo)
bull Modules supported by a primary structure
Modular units may be designed to be supported by a primary structure at a podium or
platform level In this case the supporting columns are positioned at a multiple of the width of the
modules (normally 2 or 3 modules) The beams are designed to support the combined loads from the
modules above (normally a maximum of 46 storeys) The supporting structure is designed
conventionally as a steel framework with beams and columns that align with multiples of the module
width and provides open plan space at ground floor and below ground levels This form of construction
is very suitable for mixed retail commercial and residential developments especially for residential
units above commercial areas or car parking etc particularly in urban projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
25 | P a g e
Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the lower levels
(wwwsteelconstructioninfo)
o Wood structure
Back in the days of the very first modular buildings wood was the modular construction
material of choice and nowadays it overwhelmingly remains the most used for these projects due
to its abundance and cheaper initial costs Wood-framed modular buildings however have several
notable limitations that might give a property developer pause and may even prove more costly in the
long-term repairs
Wood often lacks the strength necessary to support large building projects especially those
of multiple stories Due to this weakness wood-framed buildings are typically no taller than a few
stories a considerable limitation for someone looking to build a hotel or apartment building as
examples
Wood is flammable and vulnerable to fire which could severely damage the structural
integrity of the building requiring replacement or even worse leading to a total collapse
Wood tends to warp over time resulting in a lower quality building in the years after
completion Combined with its susceptibility to pests and mold selecting wood for a modular
structure may prove to be the more expensive choice in the long term considering repair costsmdasheven
despite initial savings
Wood is among the most wasted materials used in modern construction On average 20 of
construction lumber typically ends up in landfills leaving a larger environmental footprint than other
alternatives (httpswwwdeluxemodularcom)
Considering all those negative points mentioned earlier there are numbers of regions that
still are oriented to wooden structures as this type of housing is part of culture of the society because
of traditional architecture etc therefore typical clients prefer to build the type of accommodation
that they trusted for many years as it became the main demand of market Accessible local resources
availability of necessary knowledge for construction and compatibility of labour forces with this
method are other reasons to be chosen over the other alternatives
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
26 | P a g e
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other metals
(vanguardmodularcom)
o Concrete modules
Precast concrete is a well-established and efficient manufacturing industry and products
range from hollow-core slabs to beams and columns in structural frames Concrete modules can be
manufactured in two ways either from precast 2D wall floor and ceiling panels or as 3D modular
units which are generally cast with an open base Concrete modules are often used in high-security
applications as they are extremely resistant to damage
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma Beton)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
27 | P a g e
Types of modular buildings based on operation period
bull Relocatable Buildings (RB)
Relocatable modular buildings are designed to be reused or repurposed multiple times and
transported to different sites Relocatable Building as defined in the 2015 International Existing
Building Code a partially or completely assembled building constructed and designed to be reused
multiple times and transported to different building sites
bull Permanent Modular Construction (PMC)
PMC is an innovative sustainable construction delivery method utilizing offsite lean
manufacturing techniques to prefabricate single or multi-story whole building solutions in deliverable
module sections PMC buildings are manufactured in a safe controlled setting and can be constructed
of wood steel or concrete PMC modules can be integrated into site-built projects or stand alone as
a turnkey solution and can be delivered with MEP fixtures and interior finishes in less time with less
waste and higher quality control compared to projects utilizing only traditional site construction
Common uses of modular buildings in the market
o Education
Relocatable buildings have become a critical factor in managing student demographics and
increasing enrolments Relocatable classrooms are also ideal for swing space during new construction
or renovation Convenient flexible cost-effective temporary buildings can be delivered and
operational in as little as 24-hours These classrooms are measured for quality and code compliance
by state or third-party agencies through routine and random inspections testing and certification
services Customers may choose single classrooms or arrange multiple buildings in clusters to create
a campus feel MBI members supply steps decks ramps and even furniture Members also offer
lease purchase and lease-to-purchase financing for a variety of public and private school needs
These classrooms are sometimes referred to as temporary portable or mobile classrooms
o Construction-Site
Relocatable buildings have their roots in construction site trailers where speed temporary
space and relocate-ability are important Used as standard field offices construction site and in-plant
buildings are available for immediate delivery Standard construction is wood but steel units are
available to meet non-combustible requirements In-plant buildings are available as single- or two-
story units for industrial environments with noise reducing insulation and are typically moveable by
forklift and include electrical and communications wiring heating air conditioning and even
plumbing
o Healthcare
Relocatable buildings for healthcare applications are designed and constructed to
uncompromising standards of quality A customerrsquos new clinic hospital extension laboratory
diagnostic centre MRI unit dentist office or other medical facility can be open for business and
serving communities in as little as a few days Is your interest in serving patients as quickly as possible
in the safest and aesthetically pleasing environments available These facilities offer quick quiet safe
and clean buildings with an unlimited choice of interior deacutecor and furniture and equipment leasing
o General Administrative and Sales Office
When production demands increase relocatable buildings can temporarily enlarge a current
facility without permanent alterations to the site Because the space is not permanent many
companies are able to expand without the budget approval process necessary for traditional capital
expenses Relocatable offices can be single- and multi-story buildings configured to include
independent offices conference rooms and large open spaces for cubicles or other partition systems
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
28 | P a g e
Large and small businesses as well as local and state governments are typical users of relocatable
office space
o CommercialRetail
Earlier occupancy means quicker return on investment For retail occupancies this can mean
significant cash flow advantages Standard floorplans are available for immediate delivery while
custom buildings are built to specifications in weeks not months Unique to the modular process is
concurrent construction site-work occurs while buildings are being put together in a quality-
controlled factory Typical retail applications include new home sales centers banks golf pro shops
automobile fleet ownerships college bookstores and concession stands If a clientrsquos emerging
business needs are short-term temporary space will accommodate their financial situation space
requirements and deadlines
o Security
Relocatable buildings can be custom built for a variety of access and control situations Toll
booths tickets sales offices guard stands and weigh stations are common applications One and two-
story wood and steel buildings have straight walls or walls that are tilted to improve views and reduce
glare
o EmergencyDisaster Relief
There is simply no other means of providing fast transitional shelter and basic community
needs following natural disasters than relocatable buildings Relocatable buildings can be quickly and
efficiently deployed for emergency shelter medical and educational needs or to accommodate relief
workers
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction report MBI 2019)
Construction phases
Modular construction is the process of manufacturing multiple building sections in a facility
for assembly at a remote building site The building sections called modules will fit together once
assembled on site with plumbing HVAC and electrical connections running throughout One of the
great advantages in the modular construction process is that many of the processes happen at the
same time which can cut the construction time in half There are six common steps to complete a
modular project Design amp Engineering Permits amp Approvals Site Development Plant Fabrication
Transportation and Installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
29 | P a g e
Figure 2 34 - Overlaps of phases in modular construction project
o Step 1 Design
The design phase of the modular building process creates a description of the building usually
represented by detailed plans and specifications A thorough customer consultation with a Palomar
project manager gathers the information required to develop the building plan Once this information
has been gathered the design team will produce the ideal modular building design to fit the customerrsquos
needs
o Step 2 Engineering
Each building design goes through the engineering department for an engineering review Like
site-built structures modular buildings are subject to a series of national state and local building
codes that ensure the building meets a set of standards for safety and performance State level
building codes can be superseded or augmented by local building code requirements and then must
confirm the design proposal meets all applicable building codes
o Step 3 Permits amp Approvals
A construction permit or building permit is a permit required in most jurisdictions for new
construction or major renovations Typical construction permits required can include
Site plan
Building permit
Mechanical permit
Plumbing permit
Concrete permit
Encroachment permit
Sign permit
Flood district development permit
The building owner is ultimately responsible for securing building permits for work on their
property In practice most building owners appoint the general contractor as an authorized
representative so the contractor can obtain the required permits The building owner is advised to
confirm that the general contractor has secured the proper building permits for their project Failure
to obtain the proper permits can result in significant fines penalties and even demolition of
unauthorized construction
o Step 4 Site Development
One of the advantages inherent in modular construction is that the site development and
building foundation are prepared while the modules are being fabricated at the manufacturing facility
and transported to the job site The site development and building construction processes happen
Permits
Design amp Engineering
Site Development
Plant Fabrication
TransportationOn-site installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
30 | P a g e
concurrently instead of sequentially like site-built construction Projects are developed on a variety of
geographic settings typical site development includes
Surveying
Demolition
Excavation
Grading
Site drainage
Foundation construction
Utility installation
There are two primary modular building foundation classifications on-grade and raised or full
foundation An on-grade foundation is generally for permanent installations and is more expensive A
full foundation can be used for temporary or permanent structures it is less expensive to install and
it is more cost effective to relocate the building later while causing minimal site disturbance
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom)
bull Step 5 Plant Fabrication
There are two scenarios for steel modular constructors There are few numbers of off-site
plant which built their own steel frames inside the plant because of high initial budget and it is
common that it would be cheaper to order the frames from another supplier and transfer to the
factory to assembly with other parts The steel frame is then loaded on the main factory production
line where the sub-floor is insulated and floor decking is assembled atop the steel frame As the
module moves down the production line framed wall sections are fabricated insulated and hoisted
in place The truss roof assembly is built in components at ground level before it is hoisted into place
The module proceeds down the line where mechanical electrical and plumbing services are installed
while the last of the insulation goes into place Interior finishes like drywall painting and flooring are
applied while doors and windows are installed
On the last stop of the production line the exterior finish and trim are applied before the
module is prepared for transportation
During construction at the manufacturing facility a third-party inspection agency is present to
ensure the modules are built in compliance with building code
bull Step 6 Transportation
The fabricated modules are shipped over the road by carriers that specialize in modular
building transportation In most US jurisdictions building shipping limitations are 16rsquo in width and
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
31 | P a g e
between 70rsquo amp 90rsquo in length per module Permissible Maximum Dimensions of Lorries in Europe and
UK for Lorry or Trailer are 4m in height 255m in width and 12m in length (International
Transportation forum)
bull Step 7 Installation
A general contractor often one specializing in modular construction will install the modules
complete any on site finish out and make the final utility connections
The choice of building foundation determines how the building will be installed Permanent
semi-permanent and on grade foundations will require the modules to be set with a crane Raised
foundations typically used for temporary buildings allow the modules to be set in place through
simple mechanical methods
With the modules in place final finish out of the interior and exterior proceeds Finish out can
include electrical and mechanical system connection between modules stairs wheelchair ramps
skirting exterior siding trim and utility connections
Literature review on possible advantages
Modular construction comes with advantages which motivates investors and innovative
constructors to apply this method on their future projects Here these benefits are being classified in
various sections such as schedule economic environmental health and safety and social-laboral
advantages
Scheduling benefits
While on-site constructors are complaining about the slow progression of construction
activities and delays on project deliveries the struggle is still to be continued to find new methods to
improve productivity and progression speed while maintaining the quality at a reasonable level
whether if its achievable or not On the other side modular construction because of numbers of
reasons is making a significant boost in term of time management in many phases As it can be seen
in figure 236 McKinsey amp Company report explains that approximately between 20 - 50
scheduling improvement can be achieved in comparison with traditional on-site construction
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method (McKinsey amp Company
2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
32 | P a g e
To be more specific literature reviews identified numbers of benefits in most of the
constructive activities from design to on-site installation As the table 22 illustrates off-site
manufacturing brings most of the time saving to the project by better coordination precise quality
management and not being affected by the on-site bad conditions Table 2 2 - Possible benefits in projects scheduling
In addition design can the ability to be applied in multiple projects instead of just one which
accelerates the project schedule significantly Various overlaps in modular construction can save lots
of time in projects such as site preparations off-site manufacturing and on-site installation with each
other
The acceleration in design process which would be ideal for schedule-critical projects (for
instance emergency accommodation for people who are affected by natural causes) also Long-lead
items can be stocked Fabrication can start and finish earlier in this case In the real state point of view
in the design phase there is one huge benefit which will be so handy when nearly ldquoshovel-readyrdquo
design documentation is needed for clients and site selectors (wwwmcminnvillebusinesscom)
The simplicity precision and clarity of the design plans in modular projects can increase the
possibility of using advanced software such as BIM which reduce the period time of designing phase
significantly With the increasing the possibility of integration of BIM in construction project
incorporating modular building technologies into project becomes more developed and
manufacturing and construction process could be streamlined (Na Lu and Thomas Korman 2010)
About 90 percent of the build activity takes place indoors which means the building process
is nearly guaranteed to stay on schedule That predictability and reliability enable you to count on
timely project completion If a skilled modular crew only spends half the time building your structure
than a site-built crew would your labour cost also gets cut in half
Because of stability of production location there are numbers of advanced technologies
which are being used in other industries production lines that can be used in these off-site facilities in
order to improve the productivity and reduce the timeline of the activities
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
33 | P a g e
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom)
The nature and outdoor construction have always mutual effects on each other mostly in a
disfavour way Site conditions often cause negative impacts on the activities which lead delays quality
insurances or stop them because of safety matters In result the project schedule can be changed and
most of the times unpredictive delays will take place in the timelines In addition there are sites which
the possibility of on-site construction for most of the year is almost zero percent or if exists would be
limited because of life risks for workforce A reasonable solution for these cases is off-site construction
which in most of them reduce the nature effects Thus factory-based production can make a
revolutionary impact on the project scheduling In modular method 60-90 of the construction work
is completed in a closed factory environment and this mitigates the impact of unfavourable weather
(FLORI MURESAN on ny-engineerscom)
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
34 | P a g e
Machinery equipment can take place in mentioned phase instead of human labour which can
boost the productivity quality as well as the time reduction Robotic assembly is one the efficient
examples of this technology One of the very first EU projects carried out in the Robotics Lab
(httproboticslabuc3mes) located at the Carlos III University named FutureHome-IF7 project The
done research was focused in the robotization and industrialisation of the final stage of the
construction process by mean of modular construction (Martinez 2008)
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes)
Economic benefits
Economic advantages can always attract investors to develop innovations Since in a project
time and cost have a direct and mutual relation with each other most of the benefits which were
mentioned earlier in the schedule section can also make positive impact in projectrsquos economy In
some cases these benefits equal to the initial costs which will be discussed later in challenges As it
was mentioned earlier the design plans can be repeated multiple times in projects because of
similarity of requirements that can save design costs in future budgets
Modular building because of their standardization and classification in design phase can be
more compatible with advanced such as BIM (building information modelling) BIM technology in its
5D phase does cost estimating material quantifications and pricing to be automatically generated
and modified while changes are applied for each building module (Na Lu and Thomas Korman 2010)
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
35 | P a g e
Foundations do not have complexity in modular buildings because of weight of the modules
which have to be manufactured lightly in order to be transported simpler to the location
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk)
Also because of the high quality and precise off-site execution there are fewer reworks in
modular products which can save costs in projects Off-site manufacturing provides more economic
benefits such as reduction of salary wages due to a smaller number of workers and more specialized
ones and adding values to each hour of work by increasing productivity to the activities
Moreover massive orders of Materials to the supplier can bring more quality to the material
multiple discounts on each offer and add more stability in prices of material in instable markets Table 2 3 - Economic benefits in modular method
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
36 | P a g e
Environmental Benefits
A highlight among the modular constructionrsquos benefits is in the environmental point of view
Since the modular buildings are friendly with environment many clients are willing to change their
method to this ecological approach in order to make their projects more sustainable and promote
their product in the market as an innovative constructor in the industry such as ldquoGrupo Consentinordquo
which not only builds modules that are available to use solar panels as energy supplier but recycle
many structural and non-structural elements and reuse them in another projects Waste management
can be applied simply in modular construction by reduction in waste during off-site production recycle
and reuses in elements in several projects use of automation can secure waste reduction at a high
rate It has been proven that modular construction can reduce waste by up to 90 thanks to off-site
construction (JAHNAVI SAJIP ny-engineerscom)
Agostinho Mendonccedila in 2018 did a research about reuse in construction industry which
shows a great improvement in terms of sustainability During 2022 FIFA World Cup in Qatar football
fans will have the opportunity to enjoy the stunning views of Doharsquos skyscrapers and be marvelled at
the unique Ras Abu Abod Stadium Its design concept results in a good cost-efficient arena with an
elegant curved square form
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images)
This innovative stadium will also allow it to be completely disassembled after the World Cup
Precisely many elements of the arena including all 40000 seats the containers and even the roof
will be reused providing valuable infrastructures to sports and non-sports projects elsewhere
Moreover off-site manufacturing can reduce emissions much more than conventional
method In 2009 Al-Hussein et al focused on the construction phase of modular and conventional
buildings and compared their CO2 equivalent emissions They analysed a 42-suite multi-family four-
story residential modular building located in Alberta Canada All the construction activities needed
for this building and a similar conventional building such as material delivery transportation
workforce trips equipment usage and winter heating were identified separately Therefore CO2
emissions from each of these activities were quantified The authorsrsquo analyses showed that modular
processes led to a 43 reduction in CO2 emissions compared to on-site processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
37 | P a g e
Table 2 4 - Environmental Benefits
While the on-site construction disturbs the sitersquos neighbourhood with noise dust congestion
and waste modular construction performs better by providing minimal project site disturbance
(Mohammad Kamali2016) Since most of the construction process takes place offsite there is less
impact on the project surroundings Modular construction reduces the number of vehicles and heavy
equipment required on site which translates into reduced pollution and less site disruption
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site (wwwcadoltocom)
Energy consumption in the occupancy phase of modular buildings dominates the other life
cycle phases This phase alone accounts for more than 70 and up to 98 of energy consumption and
consequent impacts over the life cycle of buildings while the contribution of the construction phase
is relatively small (M Kamali 2016) Sustainable material selection optimum modular factory
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
38 | P a g e
location and availability of labour which lead to less embodied energy consumption are effective
opportunities to reduce the life cycle energy consumption and the subsequent environmental
impacts In addition a smart design of insulation which is advanced in modular buildings can achieve
a high amount of energy use saving during the operation phase
Figure 2 44 - various layers of a module building unit including insulations (wwwsteelconstructioninfo)
Health and security benefits
When it comes to safety modular method can offer advantages for both phases (construction
and operation) to workers and future users Converting possibly dangerous on-site activities to an off-
site plant that there the supervision and control is much higher can reduce the accidents for the
workforces and the products It is obvious that the safety plan can be applied much more efficient in
a factory environment Not only is there a reduced risk of slips trips and falls ndash particularly as work
at height is reduced but there is also a reduction in onsite activity thus ensuring health and safety
always remains a top priority from start to finish
Furthermore if necessary factory operations can continue 247 with less risk of noise and
disruption to workers Work is also unaffected by the weather and other environmental delays which
could result in the project being turned around even quicker
On the other side during the operation phase safety can be improved for instance fire
protection can be designed by using multiple insulations and protectors inside the panels
One of the examples is Actavorsquos plan for Ensuring everyonersquos safety is at the heart of Actavo
what does and in line with this they have developed the HEART (Help Eliminate All Risks Today)
procedure Devised and implemented in the continuous effort to create an accident and incident-free
environment the HEART behavioural safety observation process sets the whole Actavo teamrsquos
expectation every injury is preventable so do not let any happen (Hannah Vickers b4edcom)
Modular construction generally achieves these requirements using fire-resistant plasterboard
conforming to BS EN 520 Alternative materials such as cement particle board and gypsum fibre board
may also be used in combination with plasterboard as the facing layer In residential construction
each dwelling usually forms a separate fire compartment All walls and floors that provide a separating
function between compartments require 60 minutes fire resistance In hotels and other residential
buildings each bedroom may form its own compartment (wwwsteelconstructioninfo)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
39 | P a g e
Figure 2 45 - Compartment floor at junction with external wall and compartment wall (wwwsteelconstructioninfo)
Social-Laboral benefits
Most of the mentioned benefits including economic scheduling environmental and safety
advantages have direct effect on social well-being as well Therefore they can also be named in this
section Future users can benefit from the quality of building energy savings etc which leads to
costumerrsquos satisfaction among the public Due to the shorter on-site schedule there are fewer
negative impacts on local businesses urban beauty image than conventional constructions Also
modular construction demands more skilled workforce and experts which can create more jobs for
these group of labour in the regions that struggle with high unemployment rates
In addition every industry needs to trust innovations in order to improve the science and help
the innovator to break limitations and explore new alternatives to solve problems Modular
construction as it was mentioned can be a great solution for the productivity problem in construction
industry and by applying these method it is possible to even find more solutions in the future which
can increase these rate more or solve other problems that nowadays are common among players of
construction industry Table 2 5 - Health and safety amp Social-Laboral advantages
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
40 | P a g e
Modular Construction role in COIVD-19 Pandemic
Recognizing the urgent need to create modular critical care units for rapidly growing numbers
of COVID-19 patients HGA Architects and Engineers partnered with Boldt Construction to design and
build a new system within a noticeably short timeframe ldquoThe initial idea was to provide rapid
response for hospitals and build a product with off-the-shelf readily available parts because we did
not know what the supply chain would be like Over the course of three weeks we went from concept
to full design and fabrication was underwayrdquo reports Ben Bruns executive vice president of Boldt
Construction in Appleton Wis (Rapid Response by Barbara Horwitz-Bennett 2020) The final product
was a prefabricated modular solution for assembling field hospitals capable of providing airborne
infection isolation rooms
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use inside convention
centres arenas and temporary structures Image courtesy of HGA and The Boldt Company (prismpubcom)
These Strategic Temporary Acuity-Adaptable Treatment (STAAT) units are isolation units with
enough clearance for safe bed transfers and accommodate equipment and a reclining chair These
multifunctional modules can be used as supplemental interior isolation rooms within an existing
system of care as a modular system connected to an existing hospitalrsquos infrastructure or as a self-
sufficient temporary hospital with its own infrastructure
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The Boldt Company
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
41 | P a g e
PCL Construction has come up with a similar solution in collaboration with Thor Plumbing and
Heating f-BLOK Architecture EH Price Industries and P4 Electrical Contractors Called ldquoQuaran-Tin
Podsrdquo the units are emergency response modular isolationcare rooms that provide temporary and
reusable emergency isolation for care and treatment of COVID-19 patients Each unit is self-contained
with built-in power heating and cooling as well as connections for medical gas oxygen and vacuum
Highly scalable and customizable the pod is continuously negatively pressurized and all the exhaust
is HEPA filtered Citizen Care Pod is a smart screening and testing pod that integrates intelligent
technology within a modular design to support a safe responsible recovery for governments
businesses and communities Customizable with the capabilities to enable full-on mobile COVID-19
testing in high-traffic environments the project will help in testing screening and eventually
vaccination on a mass scale (Christele Harrouk on archdailycom)
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction (archdailycom)
The Citizen Care Pod is a turnkey solution that accelerates recovery for businesses and public
institutions such as airports offices sports and entertainment complexes construction sites and
more by rebuilding staff and customer confidence that your organization is equipped to ensure their
safety
Unfortunately the COVID-19 pandemic is only intensifying the housing crisis Further
complicating the issue is the fact that a significant percentage of skilled labour workers will be retiring
within the next couple years which will significantly impact the construction industry As stated in
MBIrsquos ldquoThe US Construction Industry A National Crisis Loomingrdquo there are currently not enough
skilled workers to build all of the projects that need to be built in the same manner in which they have
been built in the past ldquoThere is no other choicerdquo advises Hardiman ldquoIt is now time for our
policymakers to start looking at alternative ways to build everything and we think that modular
construction should be a part of that solutionrdquo Along these lines the COVID-1 Response Page also
includes links to articles illustrating how MBI membersrsquo systems and facilities are currently being used
in housing infrastructure and COVID-19-related projects
Review on common challenges
Initial costs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
42 | P a g e
To start the modular construction method in an area there will be a significant investment
to establish a production plan and then designing team who must work alongside the execution
engineers parallelly in the design phase
factory cost Like any other industry modular construction demands a production line which
is an off-site plan with a supply chain based on 3D volumetric products First the off-site plan must be
designed based on the local requirements amount of demands availability of experts and labours and
budget that manufactures are willing to invest on this technology These factories are mostly
expensive to be build and the issue of production costs will always be a barrier to innovation in
modular construction because both the client and the architect will expect lower fabrication costs
However the art of every industrial innovative player is to study the economic pros and cons
of issued technology and then the industrial expert by doing couple trade-offs between the benefits
and disadvantages can make the decision whether to apply the new method or not Modular
construction is not an exception of this fact A local study can tell the investors if the approach would
be reasonable in all term and not only economic terms for the society or not Thus due to the
economic benefits that were mentioned earlier in numbers of regions which the labour salaries are
higher and the balance between transportation costs primary material access and costs experts
existence local market and their demand of real state and initial costs is more favourable modular
construction can be the best solution to apply On the other hand nowadays there are numbers of
region which the investors of industry are eager to use innovative method with higher costs that have
positive influence on environment and public health in which modular construction is more friendly
than the conventional method
Figure 2 49 -Balance between Initial costs and Economical benefits
First design costs and errors By changing the traditional construction products a change of
design is also demanded Modular design can be based by the production linersquos technologies the
budget of manufacturer and the final products quantity and quality In the earlier discussions about
design phase the complexity of 3D volumetric design had been mentioned and surely in the first
attempts would be expensive for the manufacturer However if the design could focus more on the
standardization of elements repetition in production line and consider integrate with modern design
software in order to provide more executive details and minimize the future errors and reworks the
rework cost can be eliminated and the design sample can be used for numbers of projects as a
catalogue with few changes Therefore by having these advantages the initial design cost can be
recovered soon and even make more benefit by the time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
43 | P a g e
Architectural challenges
One of the main group of experts who have argues about modular buildings are the
architectures who always suffer from limitations that this approach puts on their design process Most
of these challenges are mentioned below
bull Manufacturing technologies effect on the design One of the challenges which the manufacturers
can struggle is to consider a production line that be able to produce a wide range of product so
that there will be fewer limitations on the design phase This goal can often be impossible because
of the predicted budget of investors limited area of production plant and lack of technologies
Thus it is the architect who must be flexible with the production line and its boundaries
Moreover it is the art of the architect which can maintain a balance between ability of production
line and attractivity and innovation of the final product for the market and the industry
bull Transportation boundaries on architecture It is a fact that the transportation of modular
construction have puts limitations on the architectrsquos works The modules must obey the
obligations and regulations of the region that want to be transported in Therefore architects
must design modules which are transportable and minimize negative economic and timing effects
for the project In addition in the designing process environmental aspects which can be
happening during the transportation phase must be considered
bull Regional architecture specializations There are cases in which an off-site production plant ships
same model of modules for numbers of projects which are going to be assembled in variety of
regions with different climate cultural architecture and local construction regulations which can
surely have negative effects on the regionrsquos construction industry real estate market and cultural
architecture aspects For instance the harmony of the angel of sunlight and the windows
formation and dimensions in a residential building located in eastern region and western ones
which reduce or increase the sunlight absorption inside the building for the residents In this case
if the same form of modules will be transported and assembled without of any changes the
unsatisfaction of future users can be increased and in a result the demands can be reduce
significantly which could cause a failure for the real estate and construction industry of the region
In terms of architectural culture modular manufacturers must consider the traditional
architecture of the location in the designs in order to make sure that the harmony will be kept
among the present buildings and modular ones
bull Lack of knowledge about modular buildings among architects Manufacturers argue about the
lack of enough knowledge of architects about the modular fabrication process The third-party
inspections and approval process Transportation methods and its boundaries Onsite assembly
procedures The cross section of a modular structure which can reduce their understandings from
manufacturerrsquos demands of project and result a unsuitable design for the final products These
disagreements come with every innovation in civil engineering society which architect must follow
their lead most of the time The solution for this cause is to educate the architects by planning
workshops by the manufacturers or internships during a project so that architects can improve
their knowledge and gain actual experiences by observe and participating in real projects
bull Unfeasible on-site finishing Common architectural innovative designs focus a lot on finishing
works in order to gain attentions of buyer and improve attractiveness of buildings There are
different views about this subject Some manufacturers think that the finishing process must be
as simple as possible or minimize the schedule and costs on-site to benefit from the project On
the other hand architects believe that the modular buildings are not attractive enough because
of repetition in their design and try to focus on finishing process to make them desirable to the
market or improve the products in architectonic point of view
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
44 | P a g e
Transportation challenges
By transferring most of the construction activity to the off-site plant transportation plays a
vital role in the projects so that in case of poor logistic management can damage numbers of benefits
which were achieved in the factory plant
bull Dimensional and weight barriers based on type of transportation The type and technologies of
every modular constructorrsquos logistics can affect the project from the design phase to the on-site
assembly These effects can change the dimensions weight and structural features of the product
For instance modular structures transported on a flatback trailer will be limited in length width
and weight based on the physical capacity of the truck Components fit into shipping containers
are best suited for projects overseas because the structural integrity of the containers allows for
unorganized stacking However components will be limited by the interior dimensions of the
container in length width and height (Joseph M Schoenborn 2012)
bull Long distance transportation and lack of existence of local factory Off-site plants are not
available for every site location in numbers of states or even regions yet because of poor
development of these method in those regions Therefore in some cases the modules must
shipped even overseas to the site location to be assembled Long distance and its possible
difficulties during ground or marine transportation can bring extra costs for the project which
must be studied economically before the biding process
bull State regulations on structures dimensions and strategic issues Estate laws can always put
boundaries on construction industry and modular constructors are not an exception Every region
has its structural and transportation regulation which limits the final product In addition estate
approval during transportation phase can harm the projectrsquos scheduling program and put delays
on the arrivals or even occasional penalties which causes extra costs in the budget
bull Negative effects from environment on the modules during the transportation While the
modules are being transported to the site these products are in direct exposure to the
environment such as sunlight rain wind and other natural causes By the time possible damages
can be appeared in the modules which in some cases can be too critical that module need to be
repaired or replaced to be used On the other hand ground transportations can cause vibrations
on the trucks and its loads and the intensity of damage generally increases with the roughness of
the road surface which in some creates cracks or more critical damages on the structural element
installations or finishing The solution is to use To minimise transportation difficulties the vehicle
having vibration absorber can be used to minimise damage due to vibration and additional
precautions need to be considered for wider modules while low bed transport vehicles are
preferable for transporting taller modules (W Ferdows 2019) Moreover loading and offloading
processes must be carefully done by precise strategy and adequate equipment in order to avoid
the harms on the products
bull Transportable materials There are two terms which force modular constructors to use advanced
and high-quality materials transportation and design situations Transportation as it mentioned
earlier puts limitations on the final product and force the constructors to use material which have
less weight more against resistance road vibrations and endurance against sunlight and humidity
exposures In one word these materials must be part of a final product which can be
transportable Often these materials add costs on the project because they are more expensive
than the ones which have been used in conventional buildings All properties need to be
structurally sound in situ but units built using offsite construction methods also need to be
structurally sound whilst being raised and lowered throughout the transportation and assembly
stages of the process Key structural elements such as beams columns and potentially walls and
floors must be repeated in three-dimensional modules for transportation purposes This can
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
45 | P a g e
significantly increase material costs depending on the material choice and level of design
optimization (McKinsey amp Company 2019)
On the other hand numerous benefits which modular construction has in terms of material
such as less reworks discount on massive offers no exposure to natural causes and its off-site storage
and less waste during the production can assure the constructors that these challenges can overcome
the fact that modular buildings work better than conventional ones in a material criteria
Wrong perceptions among public and real estate market
Innovation without correct publicity brings wrong perception among people and markets
Also errors bad experiences of users and unprofessional works can change the mindsets quickly by
unsatisfying the users and in result investors During a period in past off-site accommodations were
mostly for temporary uses with low quality material and less functional features The demands of
permanent housing raised after a break such as world wars for those who lost their houses and
refugees that wanted to live abroad Therefore numbers of companies started to modify their off-site
products in order to have more lifetime and serviceability However there were constructors who
could not provide buildings with better functional services and the users became unsatisfied and lost
their trust in these products This wrong perception had been raised even until now that off-site
building such as modular ones will not serve a long lifetime and have low quality material incommode
and unattractive design and a poor functionality Obliviously bad perception of people will reduce the
demands and destroys the market as well
Today the industry recognizes the need for durable construction for even temporary uses
making it possible to move and re-use full buildings So a lack of knowledge among consumers as to
what is possible can prevent design innovation In order to overcome the stigma sometimes associated
with modular construction manufacturers attempt to offer a built product indistinguishable from one
built onsite Therefore the industry advertises a direct alternative to onsite construction In a
comparative analysis of the two processes time savings and worker safety stand out as the primary
advantages of modular construction over onsite construction The building manufacturing process
itself construction in a controlled environment with access to advanced technology is an evolution
of the art of building which is traditionally slow to evolve The modular building industry therefore
should advertise a different building product altogether featuring design innovation and ingenuity
executed through advanced building techniques (Joseph M Schoenborn 2012)
Moreover in order to raise the demands among the public who can be future users a range
of positive publicity about the environmental advantages such as less emission economic savings like
less energy bills cheaper and easier maintenance processes during the operation phase and faster
construction process which help them to be accommodate sooner can create a positive mindset
among the public In addition post-sell services from constructors such as better assurance policies
for buyers maintenance services and offering loans to customers who are in emergency
accommodation needs can change the market significantly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
46 | P a g e
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects (casasinhauscom)
Integration of advanced software
As it mentioned before modular construction can benefit from using innovative software in
their designing phase in order to be more precise on planning and provide detail for the production
line One of these software programs is BIM which can be used in design construction phase on-site
assemble and even operation phase However despite its advantages there will be some challenges
as well The greatest challenge of using BIM in construction project is the implementation process
itself regardless of the software capabilities Development of accurate BIM model requires extensive
resources and in-depth knowledge of construction methods and process Most small or medium firm
could not afford the special team and man hours to aligning BIM (Na Lu and Thomas Korman 2010)
Other than finance and organizational issues the project team has experienced legal challenges as
well The use of BIM technology encourages multi-disciplinary collaboration which contrasts to
defining responsibility to each party and then assigning liability issues among the parties In addition
using BIM models instead of traditional contract documents raises questions on insurance coverage
and confidentiality exposure Ownership and control of the model use and distribution of the model
and intellectual property rights are some of the issues that need to be addressed while BIM
implementation being adopted in construction industry
Redefining the contracts
Due to the changes over the responsibilities of every participants the amount of their
influence on projectrsquos activities and transferring most of the work to the off-site plant a new way to
contracting is needed in order to optimize the relationship between the owner designers and
manufacturers during all phases of the project Here are some of the common types of contracts which
are being used among modular building industry
bull Design-build The architect modular manufacturer and onsite general contractor are
hired as a team and assume the responsibilities of design and construction together DB contract can
be named one of most traditional types of contracts that would create an integration between all the
parties of a project Due to the design-build nature of modular construction a close partnership is
demanding during the project phases
bull Design-bid-build After the architectrsquos design has been approved by the client a
competitive bidding process takes place This results in a greater disconnect between parties The
common gap between participate happen a lot in this type of contract which frequently can cause
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
47 | P a g e
misunderstandings about responsibilities of each expert incomplete information about the project
design or executive details and lack of transparency among the participants
bull Negotiated bid The modular manufacturer is hired first by the client to find the
appropriate architect and onsite general contractor that can be hired within the constraints of a
budget This concept may increase bonding between experts and improve everyonersquos understandings
about many aspects of the project But the budget will decide whether the quality level design
enhancement can meet the clientrsquos requirements or not In addition in case of clientrsquos approval the
question would be the future userrsquos satisfaction can be achieved or not due to the budget limitations
on the project quality level
bull Certified Modular Architect (CMA) A sustained relationship between an architect
and a manufacturer can be developed over multiple projects Therefore a certification process
providing training and continuing education can be introduced to the modular building industry An
architect intimately familiar with modular construction is best suited to handle coordination issues
that arise when work is being done in the factory and onsite simultaneously A it mentioned earlier
architects understanding and knowledges is critical to avoid possible mistakes and unsuitable designs
for modules Therefore this certified education which can be called as a semi-professional internship
for the design team in order to be present at every phase of the project
Supply chain-transportation-onsite assembly management errors
One of the main objectives to use prefabricated elements in construction is to raise the
productivity in execution phase which is mostly happens in off-site plant As it mentioned before there
is a supply chain in manufacturing plant and its productivity is depended to many key factors which
will happen outside of the factory Continuity of assembly operation is one of them which would be
happening in parallel with off-site supply chain After the modules were prepared to be transported
to the site the transportation system must be synchronized with the factory delivery and assembly
demands If any delays may happen during the transportation would affect the both origin and
destination scheduling storage policies and demands
On the other hand assembly line also must on-time and well-communicated with off-site
plant experts because any changes in execution phase can make huge negative impacts on supply
chain productivity Therefore these three important phases must plan based by on-site demands
supply chain productivity execution management and transportation systems
Figure 2 51 - synchronization between supply chain transportation and on-site assembly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
48 | P a g e
3 Common challenges in modular construction industry by a
survey Methodology
Objective
This study used qualitative research and specifically a grounded theory methodology to
uncover more information about advantages of modular construction and its constraints or barriers
to develop this method in the market Qualitative research emphasizes the influence of the researcher
on the data collected
Role of the researcher
In this study I acted as the sole researcher who was responsible to design questions based by
literature reviews and then by creating an online survey form try to collect the data from the
participants
Ethical considerations
To protect the rights and guarantee the safety of participantrsquos information following actions
were done
1) The research objective and process were made clear to the participants
2) The collected data was used for research objectives only
3) Only eligible participants who are modular constructors and manufacturers were
chosen for this survey
4) The access option to the survey information gave to the participants after the
research was finished
5) The anonymity of the participants was maintained
6) The name of the participant and their brand was remained confidential for all roles
even the researcher to obey the law of data protection
Survey setting
Due to the emergency restrictions which caused by a virus pandemic across the world several
options were unavailable to be done such as face to face interviews factory visits and project site
practices Therefore online interview was the only solution which can be happen without any danger
for participants and researcher In most regions construction companies are suffering from a full shut
down on their production line and on-site projects so that access to these participants became even
harder than usual Thus an online survey form by office forms was chosen for this research so that
the participants can answer the form questions at any time and location with ease to answer by
multiple accesses to the formrsquos link (Figure 31)
This survey forms had been sent by email to the official addresses that were mentioned in
their websites for contact The priority in choosing the recipients were the construction managers
project managers and executive engineers so that the information will be collected from the operation
managers who have the most technical experience and have the most knowledge with construction
phases from off-site production to on-site installation This could also help the survey to find the
challenges during the construction that were not able to be visited due to the restrictions of global
pandemic
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
49 | P a g e
Figure 3 1 - Online office forms for survey use
The estimated time was reduced to 13min with the most important questions to improve the
efficiency and be timely reasonable for the participants
Development of questionnaire
After hours of study on numbers of articles which have focused on challenges in modular
construction industry several were found that have lack of scientific scope and recommended
solutions Therefore many of the questions were designed to first shed a light on the potential
advantages which have not been mentioned specific and completely unknown for the industry For
instance the social benefits which came immensely useful during the COVID-19 pandemic for health
centres and medical infrastructure etc Moreover a lack of inconsistency between industry and
science came to notice which shown a massive gap between these two important roles in construction
industry This gap explains that the scientific researchers in some areas have the minimum contact
with industrial players in construction world in comparison with other industries which the opposite
situation is applied To fill this gap questions were designed in a way which have an origin of scientific
researches and direct and first-hand information from the construction industry players which are
constructors modules manufacturers etc
Development path of questions can be explained as critical path to the best details of each
criteria than can obtain useful information from participants In terms of advantages the benefits
which were identified from literatures were ordered and asked form participants to be confirmed and
validated by the industry players in real project cases For instance in an environmental point of view
Reduction in Energy Consumption was identified in literatures and had been asked among participants
to confirm the hypothesis that modular construction can reduce the energy consumption in
comparison with traditional methods (Figure 32)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
50 | P a g e
Figure 3 2 - Questionnaire development
Participant profile
Experience amp professions
As the ldquoTable 31rdquo explains information from five companies have been selected for this
survey with variety of backgrounds from pioneers to well-experienced players in industry with over
than 120 years of experience in the modular construction society as constructors and modular
manufacturers The experts who answered have different roles in the industry from CEO to architect
and sales managers so that the data can have more perspectives of views on the questions such as
sales market and design process to project management Table 3 1 - Participantrsquos profiles
Because of diversity in the influence of challenges between massive international builders and
local players these five companies responds have been compared to each other from company C
which is a local constructor to company E that is currently executing modular projects in 80 countries
with approximately 6000 modules build annually
Types of materials in some cases can have different statistics in results For instance in
modular construction which steel and wood modules are more often used in projects can produce
various amount of CO2 emissions and waste or recycle process can be done with more ease For that
reason these survey all types of materials are considered including steel modules concrete modules
and wood modules There is also an argue that some benefits and challenges cannot be seen in unique
projects with more repetition in production of elements and mass production such as hotels and
schools while in residential projects can exists more than the others To cover all the contrasts of
60 of participants
can acheive a 30-40
reduction energy
consumption
A Our homes are not positive from an energy
perspective
B We can finish a 4 months traditional project in 8-10 weeks and Energy consumption of a factory is known and relatively constant on a weekly
E 30 reduction in energy consumption
Modular construction can
reduce the energy consumption up
to 30 in compariosn with
conventional methods
QsCompany A B C D E
Years of company experience 10-15 10-15 20-30 20-30 30-50
Position of participant CEO Sales Manager Design Architect Quantity Surveyor Foreign Trade Manager
Professional experience 15 13 30 NA 3
No of employeesfactoryModules build annually 801200 1301490 151- 50280 25026000
Type of material(WoodSteelConcrete) W amp S W W W S amp Conter amp fiber cabins
Types of Projects (ResedentialSchoolsHospitalCommercial) R R amp S amp C R R amp S amp C amp H R amp S amp C amp H
Use of BIM Yes No No No No
Level of automation 20 reaching up to 80 20 Off-site 60 On-site 20 20 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
51 | P a g e
information these companies have been selected that are involved in all types of modular building
projects including residential hospitals schools and commercials buildings
As it mentioned before BIM program can advance the projects in many ways however
unfortunately among these participants only company A is able to benefit from this software from 0
to 100 of the project Therefore the further arranged interview focused on BIM Function was
cancelled and may be done in the future investigations
Automation can play an important role in improving the productivity and sustainability of
construction processes as a part of ldquoindustrialization in constructionrdquo movement Among survey
participants the minimum automation level in off-site plants is 20 and maximum of 60 and in on-site
activities can be up to 40 In addition company A claimed that in near future their automation can
reach up to 80 which is an innovative move in construction industry On the other hand company
with over than 6000 modules build annually have a significant 60 of automation in their plant which
shown a massive interest of investment on this technology In addition automation application
difficulty have direct relation with the type of materials used in modules and type of the projects which
as Table 31 illustrates company E with the most variety in project types and materials use have
achieved a huge success in application of automation with a level of 60 which also helped a lot to
expand their market overseas
Data collection
General information
All the received information has been attached in ldquoAnnex 1rdquo where the responds are not
edited and mentioned in the original shape Here are the shorter versions of responds
bull Motivations to choose modular construction over traditional
To bring the attention of investors to an innovative method reasonable motivations are
needed which can be the current demands of market economic profits and environmental benefits
Therefore it was necessary to identify the motivations of these companies to start a modular
construction form Economic advantage for most of these has a priority not just for being profitable
but for being able to develop their dominance in the future On the other hand innovation has an
approximately same amount of interest which explain the reason behind choosing modular method
that is one of the most innovative off-site construction methods in the industry
The fact that mentioned before in literature reviews high demands in the market and the lack
of provide by construction players is one of most important reasons to apply a fast and high-quality
solution for reach the satisfaction of housing market Shorter schedule and environmental benefits
took the next places of priority in motivations for these companies which are also important for sure
Figure 3 3 - Participants motivations to start a modular company
28
9
18
18
27
Economic benefits
Enviromental benefits
Shorter schedule due to the need
High demands of housing in themarket and lack of provide
Innovation
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52 | P a g e
bull Built in factory panelssubcontracted panels used in modules
All five companies are manufacturing the panels that used in modules by their own inside the
off-site plant which as it mentioned earlier the selected participants have a variety of production rates
and by this information that they are able build their own panels it can be said that their production
is 100 off-site However in the case of company E which is a massive international modular player
there are some types of modules that are being provided from domestic market because of economic
feasibility issues
Economic issues
bull No of labourLess wages of salaryAdded value in each hour of workneed of
special workforce
Generally the participants mentioned that there fewer number of workers are needed on and
off site in comparison with traditional method About the amount of salary wages company A
confirms that for each hour of work off-site less amount wages are being paid to workers On the other
hand the shorter schedule of projects in modular projects can reduce the payments as well The fact
that most of the participants are emphasizing is that the efficiency of work and added value of
activities off-site are much more than the on-site traditional projects where company A acclaimed
that in terms of efficiency ldquo1 hour in the factory is equal to 4 hours on-siterdquo
Environmental status
bull Life cycle duration of products and material recycle
Company B acclaimed that they do have multiple solutions for each materials that theyrsquore
using in their modules for instance the unusable drywalls and PVC materials which they send for
recycling or the woods that would use into mulch products or for heating by others
Company E told that their products have a 50 years life span which is the same as a lifetime of
traditional build residential house However company C have some difficulties in recycle and reuse of
their elements because of unportable feature of their products
bull Integration the modules with other innovative technologies
Four of these five companies confirmed that their products have the option to integrate with
other innovative technologies such as self-powered homes by solar panels and also using advanced
insulation technics made by non-petroleum materials in their panels to reduce the energy
consumption during operation phase
bull Waste reduction
Company A acclaimed that their production line generates significant amount of 70 less
waste in comparison with traditional method The rest of the companies focused on carbon footprint
reduction and were able to reduce it 15 less that traditional method by choosing environmentally
friendly technologies in production and wise choice of materials for their products
bull Reuse of structural and non-structural elements in projects
Three of five participants confirmed that they have the ability to re-use their products in the
next projects in order to reduce the waste and energy consumption during the manufacturing
processes Type of the projects and material have the direct relation with the potential of reusability
in elements and due to the variety that the participant have in both criterions the potential is variable
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
53 | P a g e
Figure 3 4 - Re-use potential
bull Reduction in Energy Consumption
Company E mentions that modular construction can achieve a 30 of energy saving in
comparison with traditional site-build method while company A acclaimed that their homes are not
positive from an energy perspective Company B gave more details on energy consumption by making
a comparison between off-site activities and on-site traditional construction and acclaimed that due
to the shorter schedules in off-site production energy consumptions can be reduced up to 50 They
mentioned that ldquoEnergy consumption of a factory is known and relatively constant on a weekly
monthly and annual basis A competent and experienced modular builder can many times finish the
entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-
built house could require as much as 4 months for the same completionrdquo
Social Benefits
bull Delivery of projects for emergency services during COVID-19 Period
As it mentioned earlier due to the virus pandemic that is happening at moment in all around
the world a rapid response is needed more than ever for emergency services for health organizations
and according to this survey one of these companies is providing products for this cause which can be
a good news and accounted as a social benefits for this method of construction
Figure 3 5 - Contribution in Covid19 epidemic
bull Providing post-sale services for clients
In contrast with conventional construction which just have the responsibility until the delivery
of the project modular constructors because of their industrial profile have the ability to offer post-
No40
Yes60
Reuse the structuralnon-structural elements projects
No
Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
54 | P a g e
sale services to the clients such maintenances upgrades etc due to the results of this survey four of
these five companies confirmed the availability of post-sale services for their clients
Figure 3 6 - Post sale services por future clients
Initial costs
bull Initial investment and its Payback period
Company A claims that their initial investment to establish their company was about 20 million
Canadian dollar and its payback period was 5 years Company E had the amount of 15 million USD with
the same 5 years period However company C like many of the older players in modular construction
industry who started way earlier cannot estimate their initial investment
bull Factors that can change the initial costs
There are factors which can make a change in initial costs of companies The participants
prioritized these 6 chosen factors starting with product types and production range with 31 of
importance among others Level of automation took 25 share of the pie chart which has direct
relation with the initial costs Off-site plantrsquos location has 19 of efficiency on starting costs and
furthermore the quantity of sub-contracted players in the projects achieved 13 of the graph Finally
financing and design enhancement have the minimum equal shares of 6 which despite of being the
last factors have the efficiency on initial costs as well
Figure 3 7 - effective factors in initial investments for start-up companies
6
25
31
13
19
6
Factors that effect on initial costs
Design enhancment Level of automation
Product types and production range Less sub-contracted
site location Financing
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
55 | P a g e
Design limitations
bull Design boundaries caused by production line
Company A mentioned the subassemblies as the main element to be considered in design
phase while company D and company B introduce a maximum dimension for their production lines to
be economically viable for transportation costs In addition to those company C and company E
confirmed that there are no boundaries for the designer caused by the production lines because of
their wise choice of prefabrication methods
bull Lack of knowledge from architectsdesign engineers about production processes
transportation limitations etc
One of the main problems of start-up companies and the experts who join the modular
construction industry is the lack of knowledge about off-site processes and transportation limits
Three of five participants confirmed that there is lack of knowledge in these area from designers
Figure 3 8 - Lack of knowledge among designers and engineers
Transportation Limitations
bull Transportation regulation effects on modular projects
Three of five participants confirmed that the regulation by transport administrative can be
harmful for the projects such as extra costs or time delays on schedule Company A mentioned the
time delays in giving permits to the manufacturers and constructors which can damage the
synchronization between production line and on-site installation by reducing the speed of
transportation of elements to the site Company B added information about transportation system of
some states in America which use the term ldquoSuper Loadsrdquo to put limits on oversized shipping that
increases the cost and time on the project On the other side Company C as a strategy to avoid this
problem used legal load limits in their design instructions so that their products will obey the
regulations
bull Transportation boundaries on material choice and project costs
Company B D and E confirmed that the terms of special transportable material will not add
extra costs on the project Company A acclaimed that the extra costs by transportation can be offset
by speed of production and reduced financing costs for the project
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
56 | P a g e
Project management challenges
bull Difficulties in using automation in off-site production
In this survey based on literature reviews 4 main reasons for difficulties of using automation
in off-site production were selected to ask the participants Integration with advanced software and
high expenses of application in production line took approximately 60 of importance among others
Codding problem is another major problem in this subject which have 28 of pie chart In addition
company A demanded ldquoAn international coddingrdquo as a solution for this problem The last section
belongs to ldquolower salaries of manual processesrdquo which has the minimum importance of 14 among
participants
Figure 3 9 - challenges of using automation in off-site plants
bull Contracting problems
Starting with company A which acclaims that every state has its own code and the lack of a
universal code can bring challenges for modular players
Company B explained about the misunderstanding by final client who is the end home buyer
who ldquobelieves the factory to be the builder and the actual independent builder to be a sales agent
for the factoryrdquo Their recommended solution for this problem is to define the relationship between
the participants of projects their responsibilities by social media and requiring the builders customer
to sign a disclosure acknowledgement from that describes the relationship in detail
Company C mentioned a financial challenge caused by the banks in the projects that are
financed by them (Banks) which do not consider the project done until erected on-site This issue
creates pressure on cash flow of project where bank finance is involved The only problem that
company E consider in terms of contracts is lack of timing on project delivery which is generally causes
by constructors or general contractors
bull Lack of synchronization between projectrsquos participants
To begin with company A believes that there is a lack of quality partners on site They explain
that the problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution Company B mentioned that the responsibility of ensuring
28
29
29
14
Difficulties in using automation in off-site production
Codding Integration with advanced software Cost Lower salaries of manual processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
57 | P a g e
that the work is done properly belongs to the builder which any ldquodelays in this can result in postponed
transport of product and interest through demurrage charges
bull Sub-contractor for site planning and foundation phase
Company A uses local subcontractors for their site planning and foundation phases because
of variety of locations of their projects and ease of using local subcontractors Company B have only
the responsibility of modules production and defines the customer (the general
contractorindependent builder) responsibility to execute rest of the project phases have sub-
contractors if needed Company C does have sub-contractors for site-preparations and foundation
phases under direct supervision and the reason to not performing by their own is the high costs of
required equipment and not being portable for each project
bull Technology gap between sub-contractor and modular constructor
The only issue that were mentioned by participant is where company A recommended to ldquoto
educate most local subs on our process and reason for doing things a certain wayrdquo
Company B and C acclaimed that there are no challenges for the off-site production
Social challenges
bull Wrong perceptions among public and market
The only value that the market considers choosing modular method over traditional
construction is to be cheaper Company A says
According to company B experience in USA majority of people the media and even
professional engineers do not understand the capabilities of modular construction Many people
continue to confuse this form of construction with HUD on frame products
Another wrong perception that the publicmarket believes is that the prefabrication methods
limits the design options while Company C believe confirms that the reverse is the case
bull Solutions for resolving the wrong perceptions
Company A believes by using one of the main advantages of modular construction which is
shorter schedule the market can be dominated by modular projects and the more cases they deliver
the more recognised this method would be among the public and at the end the superior nature of
modular approach can be proved Company B addresses a solution in a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Company C acclaimed that advertising the modular advantages
among the public would be enough
Data analysis amp conclusions
The data from this survey can be used as an input data and prioritizations for the next chapter
which is decision-making process between four alternatives The solutions and recommendation will
be repeated at the recommendations at the final chapter as well Here are the conclusions about
advantages and challenges in modular construction mentioned by professional participants
Advantages
Economic benefits Generally apart from the other benefits as the participants mentioned
that there fewer number of workers are needed on and off site in comparison with traditional method
and Due to the shorter schedule of projects in modular projects can reduce the payments wages
Other fact that most of the participants are emphasizing is that the efficiency of work and added value
of activities off-site are much more than the on-site traditional projects
Environmental benefits Due to the variety of solutions for each material that they are using
in their modules there is high potential to send the used elements for recycling or would use into
mulch products A long lifetime span is acclaimed for the products which is close to the traditional
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
58 | P a g e
ones Majority of participants confirmed the literature concept that their products have the option to
integrate with other innovative technologies such as self-powered homes by solar panels and also
using advanced insulation technics made by non-petroleum materials in their panels to reduce the
energy consumption during operation phase In the waste management term there is a possibility for
production lines to generate significant amount of 70 less waste in comparison with traditional
method Moreover about carbon footprint reduction there is ability to reduce it 15 less that
traditional method by choosing environmentally friendly technologies in production and wise choice
of materials for products While there is argue that modular construction can achieve a 30 of energy
saving in comparison with traditional site-build method there are claims that their homes are not
positive from an energy perspective However this idea mentioned that by making a comparison
between off-site activities and on-site traditional construction due to the shorter schedules in off-site
production energy consumptions can be reduced up to 50
Social benefits As it was mentioned in literature reviews there are social benefits in modular
construction that can improve the satisfaction of clients Post-sale services for customers are possible
which is completely opposite to the traditional projectrsquos conditions
Challenges discussion
Initial costs It is obvious that a high amount of investment is needed to stablish an off-site
plant to start prefabrication of construction elements but the payback period is not that long that put
boundaries for start-up future players due to the collected information There are factors which can
make a change in initial costs of companies that are prioritized by the participants starting with
product types and production range level of automation which has direct relation with the initial
costs Off-site plantrsquos location the quantity of sub-contracted players in the projects and finally
financing and design enhancement have the minimum equal shares
Financial aids Financial assists which are crucial for kind of projects that are dependent to
these aids are not harmonized with modular project processes where there are argues that until the
first deliveries of elements to the site location and their assembly these aids are not reachable This
issue creates pressure on cash flow of project where bank finance is involved Changes in contract
conditions and education for financial supporters are recommended solutions to improve the
partnerships in projects
Design boundaries it was mentioned the subassemblies as the main element to be
considered in design phase while some players introduce a maximum dimension for their production
lines to be economically viable for transportation costs However there a possibility to eliminate the
boundaries for the designer by the production lines because by wise choice of prefabrication product
types
Lack of education The idea of lack of education among engineers and architects about off-
site construction methods was proved by the collected information which have to be resolved by
updating the education resources to innovative methods that can improve the productivity rates and
sustainability
Transportation regulations negative effects it is confirmed that the regulation by transport
administrative can be harmful for the projects such as extra costs or time delays on schedule Time
delays in giving permits to the manufacturers and constructors which can damage the synchronization
between production line and on-site installation by reducing the speed of transportation of elements
to the site A strategy to avoid this problem used legal load limits in their design instructions so that
their products will obey the regulations
Choice of transportable material effect In contrast with literature review which mentioned
the idea of extra costs by choices of transportable material this survey confirmed that the term of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
59 | P a g e
special transportable material will not add extra costs on the project Moreover the extra costs by
transportation can be offset by speed of production and reduced financing costs for the project
Automation use challenges Integration with advanced software and high expenses of
application in production line took approximately 60 of importance among others Codding problem
is another major problem in this subject In addition ldquoAn international coddingrdquo was mentioned as a
solution for this problem Every state has its own code and the lack of a universal code can bring
challenges for modular players ldquolower salaries of manual processesrdquo has the minimum importance
Defining responsibilities boundaries There is a misunderstanding by final client who is the
end home buyer who ldquobelieves the factory to be the builder and the actual independent builder to
be a sales agent for the factoryrdquo Their recommended solution for this problem is to define the
relationship between the participants of projects their responsibilities and requiring the builders
customer to sign a disclosure acknowledgement from that describes the relationship in detail
Lack of partnership among projectrsquos participants There is a lack of quality partners on site
The problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution The professionals answered that the responsibility of
ensuring that the work is done properly belongs to the builder which any ldquodelays in this can result in
postponed transport of product and interest through demurrage chargesrdquo
Wrong perception of publicmarket The only value that the market considers choosing
modular method over traditional construction is to be cheaper while majority of people the media
and even professional engineers do not understand the capabilities of modular construction Many
people continue to confuse this form of construction with HUD on frame products Another wrong
perception that the publicmarket believes is that the prefabrication methods limits the design
options while some players believe that the reverse is the case Therefore by using one of the main
advantages of modular construction which is shorter schedule the market can be dominated by
modular projects and the more cases they deliver the more recognised this method would be among
the public and at the end the superior nature of modular approach can be proved Another solution is
a form of cooperation between builders manufacturers architects and engineers to educate the
public by national entities such as Modular Home Builders Association
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
60 | P a g e
4 Decision making based on potential advantages among three
modular alternatives and conventional construction method in a
project by MIVES software Methodology
Objective
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria potential benefits can be recognised However to find out how much practical these benefits
are in the market several trade-offs must be done by professional tools such as project management
software programs which can take decisions based on the input data that receive
The objective of these thesis is to examine the practicality of modular construction by taking
the best decision among 4 alternatives including a conventional armed concrete building with steel
modular concrete modular and timber modular methods and see that the mentioned advantages can
lead the methods to become the best option to choose for building the project as a project
management point of view
What is MIVES
In order to make the most sustainable and reasonable decision among the alternatives a multi-
criteria decision-making program was used called ldquoMIVESrdquo MIVES is the acronym for Modelo
Integrado de Valor para una Evaluacioacuten Sostenible which means Integrated Value Model for a
Sustainable Assessment It is a multi-criteria methodology for decision making It allows transferring
the different characteristics of the objects to be evaluated to a series of homogeneous and
quantifiable parameters which facilitate the objectification of the choice
The MIVES methodology consists of creating a model that defines all the characteristic
features of the elements to be evaluated assigning them a function that allows converting the
different peculiarities of the alternatives into a common unit which we will call value Once the
amount of value for each alternative is obtained it can be used for a sustainable evaluation
(wwwdecaupcedu)
Data collection process
Case Study references
bull Journal of Cleaner Production (WAHammad 2019)
(httpsdoiorg101016jjclepro201904150)
This Fabolous multi-criteria comparison was done between two methods of conventional and
steel modular building in two cases case A which is a normal residential building and case B a school
building to measure the sustainability level of them in economic environmental and social areas The
location of this was considered in Sydney and central coast Australia and four BIM models had been
designed for each alternative in both cases The total floor area of Case A is 63 m2 (87m x 72m)
When adopting modular construction the granny flat is designed from 2 modules each module is
36m x 87m Case A was chosen as the study case to focus on because of type of the project that is
residential building
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
61 | P a g e
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study (WAHammad 2019)
The purpose of this journal is to add sustainability criteria as main factors for constructors to
make a multi-dimension decision whether to use Modular construction for a project or continue with
conventional methods
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and conventional methods
(Akbarnezhad 2019)
bull A comparative life cycle assessment (LCA) of concrete and steel-prefabricated
prefinished volumetric construction structures in Malaysia (Ali Tighnavard
Balasbaneh 2020)
(httpsdoiorg101007s11356-020-10141-3)
This researchrsquos focus is to compare two types of volumetric modules function in terms of cost
and LCA factors such as Greenhouse emission etc on a residential project with the approximate area
of 105m2 located in Malaysia based on local regulations Prefabricated Concrete Modules (PCM) and
Prefabricated Steel Modules (PSM) were considered for this project Recently Malaysian
administrative system has been pushing the companies and researchers to investigate on these types
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
62 | P a g e
of construction methods in order to measure the benefits and obstacles of using them in future project
and try to resolve the productivity problem in construction industry The construction industry in
Malaysia has been labelled ldquounproductiverdquo for its reliance on a large labour force and its use of non-
prefabricated strategies at a proper scale (Balasbaneh 2020)
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020)
bull Modular vs Conventional Construction A Multi-Criteria Framework Approach
published at ISARC 2017 (AWA Hammada and A Akbarnezhad 2017)
This paper did a comparative analysis in cost time and carbon emissions by BIM models
Material and equipment libraries and existent databases on a project in the North-West of Sydney
involves the construction of a granny flat with dimensions 14 m by 16 m
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017)
The framework of this papers based on the BIM model analysis with input data project actual
projectrsquos budget material and equipment used in the construction and environmental information in
database and then a comparative study on emissions during constructionmanufacturing schedule
and costs of project for crew material and equipment (Figure 45)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
63 | P a g e
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad 2017)
bull Life cycle greenhouse gas emissions and energy analysis of prefabricated reusable
building modules published on Energy and Building (Lu Aye 2011)
(httpsdoiorg101016jenbuild201111049)
Aye and his team did a LCA study on three alternatives PSM PCM and PTM which were used
in a multi-residential building with 63 apartment units with area of 63 m2
Figure 4 6 - Architectural section of multi-residential building (Aye 2011)
The modules in this study were categorized in 4 main elements Exterior walls with insulation
panels Interior walls used for internal separation which mostly build with timber frames and plaster
boards Floors with plywood material on topping in all alternatives and ceilings with thick plaster
boards and steel concrete and timber parts as main elements (Figure 47)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
64 | P a g e
Figure 4 7 - Structural elements used in modules (Aye 2011)
bull Comparing Environmental Impacts of Building Modular and Conventional Homes in
the United States published at Construction Matters (John Quale 2012)
(httpsdoiorg101111j1530-9290201100424x)
Quale did also a comparative analysis focused on Environmental emissions on two PTM and
Conventional Timber building Three residential modular companies generally representative of the
eastern US modular industry supplied data on completed projects for this study including utility
bills worker commuting information building materials and waste procedures construction
schedules employee schedules and other relevant information (Quale 2012) 186 m2 two-story
home that is a model for one of the companies involved in the study
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
65 | P a g e
Input data
4221 Alternatives
Four alternatives were selected for these study which are one conventional armed concrete
(Reinforced concrete RC) structure prefabricated steel modules (PSM) prefabricated concrete
modules (PCM) and prefabricated timber modules(PTM) that are most common solutions used by
contractors in the construction industry
4222 Requirement tree
These are groups of criteria which define a function to be evaluated A requirement usually
has several criteria Five requirements were selected based by literature review and the expertrsquos
opinions collected by survey among industrial players who were the participants of this questionnaire
Economic R1 time R2 environmental R3 safety R4 and social R5 requirements arranged in a way that
can examine the advantages adequately Time requirement were separated from economic one
because of importance due to high priority that have in the market to be chosen by the constructors
and clients In other words some clients and private builders choose the prefabrication methods such
as modular construction to save more time due to tight schedule that the project have Social and
safety requirements usually not being considered in sustainable decision-making processes but on this
study were included because the sustainability is not the only factor in project management
4223 Criteria
For each requirement a series of criteria are defined Criteria are the specific concepts that
the indicators contain the minimum unit to be quantified (wwwdecaupcedu) Each criterion was
chosen based on the importance among others efficiency on the project and availability of actual
amount and quantities in real cases over literature resources In other words the both advantages
and their functionality that modular construction have in comparison with traditional methods were
the main drivers to choose a criterion for each requirement as it mentioned earlier For economic
requirement cost of the project R1C1 was the only criteria that was considered which in the literatures
is expected to save 20 by choosing modular method in final cost (McKinsey amp Company 2019) while
experts in survey believe that the cost of transportation of prefabricated elements to the site can
compensate the difference with traditional method To examine these two opinions these criteria was
chosen In Time section the projectrsquos schedule R2C1 was only criteria to measure the important
advantage that the modular construction has Both literatures and expert agreed the time saving that
modular approach can bring to the project which is about 50
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES)
R1 - Economic
R1C1 - Project cost
R2 - Time
R2C1 - Project schedule
R3 - Environmental
R3C1 - Energy consumption
R3C2 - Waste generation
R3C3 - Material consumption
R3C4 - Noise Polution
R3C5 - Greenhouse gas emission
R3C6 - Recycle
R3C7 - Embodied energy
R4 - Saftey
R4C1 - Injury risks
R4C2 - Protection from natural cuases
R5 - Social
R5C1 - Job status
R5C2 - Quality
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
66 | P a g e
Seven criteria were chosen to cover the environmental requirements for this decision-making
process based on the available data in literatures However in this section not only advantages of
modular methods were considered but in some areas conventional reinforced concrete showed
better results and this fact can improve the liability and practicality of final decision For instance the
embodied energy of steel modular building is 30 more than the conventional during the construction
but the saving caused by re-useability of element in modular method can almost compensate the gap
between these two methods Energy consumption R3C1 which is the energy consumed during the
constructionfabrication amount of Waste generated R3C2 in all alternatives Material consumption
R3C3 in each method Noise pollution R3C4 Greenhouse gas emission R3C5 Recycle of elements R3C6
and Embodied energy for each method were chosen in this section
Safety issue as it has mentioned before was added to decide further than sustainability
concept boundaries which include two criteria Injury risk for workers R4C1 and Protection of project
from nature causes R4C2
Finally Social benefits which are not as main factors to be considered by construction players
to use the modular methods but are important enough to pay attention and were compared as well
by two criteria Job status R5C1 and Quality R5C2
4224 Indicators
The indicators for this study came directly from scientific articles which most of them were
published few months ago and it can be said that the data which were used for this study is updated
with the latest achievements in modular construction industry
To begin with for economic measurements two indicators for the project cost were selected
total project cost R1C1I1 and costs stability R1C1R2 Total project cost R1C1I1 for conventional RC
alternative means the final cost of construction including all the activities until the delivery of building
In modular alternatives PSM PCM and PTM includes the module fabrication in off-site plants
transportation installation on-site and final finishing of building after the assembly phase All
indicators are based on ldquoAustralian dollarsrdquo units (AUSD) because of the recourse quantities that was
used for this study which will be discussed more later Second indicator which is the costs stability
(R1C1R2) was chosen because of the common off-site production economic advantage that is
stabilizing the costs for the projectrsquos budget because of high quality of product more repetition of
elements and more accurate supervision on activities which leads to less reworks and less extra costs
etc
Total project schedule R2C1I1 is the first indicator for time requirement which include the
amount of time to fabricate transport and final assembly of the modules on-site in modular
alternatives and the final schedule of the conventional project during construction activities until the
delivery of the building which all are based on ldquodaysrdquo it was mentioned earlier that in off-site
production the project schedule can be estimated and controlled more adequately so that second
indicator which is time stability R2C1I2 was introduced to the study
Environmental requirement was studied in various features as it said before in 7 criteria which
shows the complexity of comparisons between alternatives First indicator is the Energy utilized during
construction R3C1I1 based on ldquoMJrdquo units Solid Waste R3C2I1 is the only indicator for Waste
generation criteria that focuses on the amount () of waste which was produced during
constructionfabrication activities in all four activities In material consumption criteria the total
amount of materials that was used for constructionfabrication of elements R3C3I1 is appointed as an
indicator to compare the benefits in each alternative based on ldquoKgrdquo Noise reduction in off-site
construction is another benefit that it has and to discuss this fact among the alternatives Average A-
weighted equivalent sound level of each construction equipment R3C4I1 based on ldquodBrdquo units was
focused on Greenhouse gas emission among alternatives was measured in CO2 that was produced
during constructionfabrication activities R3C5I1 based on ldquoKGrdquo units Two indicators were introduced
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
67 | P a g e
for recycle criteria between four alternatives recyclability or possibility of recycling of elements
R3C6I1 and Re-use of elements (Products) in projects R3C6I2 based on Percentages Embodied energy
was the last criteria which was focused on with two indicators Embodied energy used R3C7I1 in ldquoGjrdquo
units and Embodied energy saved by re-use of elements in percentages among alternatives
For safety measurements two indicators were selected for two criteria which are injury risk
level R4C1I1 for injury risk criteria and Protection level R4C2I1 for protection from nature causes both
in a qualitative unit
Job stability R5C1I1 for comparing the job status in terms of security of jobs among two
methods and new job creation R5C1I2 to analyse the possibility of providing new job positions which
is crucial in these era in construction industry were chosen in qualitative unit
The last criteria in social requirement which is quality of projects was presented with one
indicator of quality satisfaction of client R5C2I1 in qualitative unit to compare the clientrsquos satisfaction
level between alternatives Table 4 1 - Requirement tree with all indicators which considered for decision making process
Requirements Criteria Indicators
(R1) Economic (R1C1) Project Cost (R1C1I1) Total Project Cost
(R1C1I2) Cost Stability
(R2) Time (R2C1) Project schedule (R2C1I1) Total Project Schedule
(R2C1I2) Time Stability
(R3) Environmental
(R3C1) Energy Consumption (R3C1I1) Energy Utilized during construction
(R3C2) Waste Generation (R3C2I1) Solid Waste
(R3C3) Material Consumption (R3C3I1) Material Consumed in project
(R3C4) Noise Pollution (R3C4I1) Average A-weighted Equivalent sound Level of each instrument
(R3C5) Greenhouse Gas Emission (R3C5I1) Co2 in constructionfabrication
(R3C6) Recycle (R3C6I1) Recyclability of Elements
(R3C6I2) Re-use of elements
(R3C7) Embodied Energy (R3C7I1) Embodied Energy Used
(R3C7I2) Embodied Energy Saved
(R4) Safety (R4C1) Injury Risks (R4C1I1) Injury Risk Level
(R4C2) Protection from Nature Causes (R4C2I1) Protection Level
(R5) Social (R5C1) Job Status
(R5C1I1) Job Stability
(R5C1I2) New Job Creation
(R5C2) Quality (R5C2I1) Quality Satisfaction of Client
The input data for indicators are categorized in 4 types direct data calculated data estimated
data and qualitative data The reason for not having only direct data is the lack of enough literature
researches on this subject and in some cases the data were published two months before the date of
this study The variety of alternatives which is the first time that a study is going to analyse 3 modular
alternatives and a traditional method added difficulty to find useful data to do the decision making
reliable Moreover 5 articles were used for finding the correct data which each of them focused on
different alternatives The orientation of this study is the Cleaner Production journal by professor
Hammad that was published in 2019 which was mentioned earlier The reason of this orientation is
that most of the data came from this article and is more updated than the others
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
68 | P a g e
bull Direct Data
The direct data were the information that was related precisely to the alternatives without
any needs to change For instance the cost of the construction in Hammadrsquos article which can be used
without any changes The green parts on the Table 42 shows the direct data which are related to the
Hammadrsquos article Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed to be done on them
bull Calculated Data
In many indicators because of lack of existence in directly related data for alternatives a sort
of calculations were needed to change the data from other articles that related to alternatives that
are not focused in main case (Hammadrsquos article) to actual data based on the area of main article by
using accurate coefficients and ratios For instance in Hammadrsquos article CO2 was not estimated for
Prefabricated Steel Modules (PSM) alternative but Ayersquos CO2 data which is for total area of 3943m2
with 63 apartments each area of 628 m2 (close to 625 m2 area of Hammadrsquos granny flat) was used
by dividing on 63 apartments units so that results 54079 kg of CO2 for steel modular equivalent for
main case The yellow parts show the calculated data for indicators
3407000119896119892 1198881199002 divide 63 119906119899119894119905119904 (6251198982) = 54079119896119892 1198881199002 for steel modules in main case
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other studied
bull Estimated Data
Third type of input data were the necessary data which are not existed on any of literatures
of have to be estimated based on the qualitative information professional survey which have been
done before the decision making process (Chapter 3) and researcherrsquos opinions Fortunately in many
areas the data could be applied on other alternatives because of similarity of activities off-site and
onsite For instance for PCM alternative the noise and Injury risk level are approximately the same
the indicators of PSM case that have mentioned in Hammadrsquos article which are shown in green parts
in Table 42 because of similarity of off and on site activities during construction
The blue parts are the estimated data that were considered for PCM alternative based on
mentioned resources For instance the time indicator can be predicted 24 days few days more the
steel modules which is around 22 days because of the fact that concrete modules are heavier than
steel ones and has more complexity in structure for being produced that adds difficulties on
transportation process which leads to more delays on the schedule Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow)
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
69 | P a g e
bull Qualitative Data
This data was added because of two reasons first the lack of existence of direct data on
literatures and improve the literatures background on this subject and secondly to have more
influence from variety of benefits that modular construction has on the decision making process
Numbers of literatures insisted on advantages that can affect the decision making but did not
included on their data analyses at the end and this research decided to include these data and see
that how much functional can be in the decision making between alternatives in point of project
management view For instance cost stability which is better coordinated in off-site construction and
can be considered as an advantage to the decision making is not included in the literatures during
analysis and in this study is a vital factor for the economic criteria In order to add this indicator a
qualitative range was considered from 0 to 10 and four alternatives based on their functionality in cost
stability in project budget were compared to each other Traditional reinforced concrete building
which because of common reworks etc have less stability in final budget estimation On the other
side PSM and PTM which have the most repetition in manufacturing processes and ease of production
because of material type have the maximum cost stability of 9 out 10 among the others and PCM that
has less ease in production have less cost stability than other modular alternatives with 8 out of 10 Table 4 5 - Qualitative indicators
Final indicators
bull Prefabricated Steel Modules indicators (PSM)
As it mentioned before the direct data which are shown in green at table 46 do not need any
changes as they belong to the main case study while other indicators are still needed to be calculated
estimated and often considered qualitatively Aye case study have the closest data to the main case
study because of similarity of project type and dimensions so that the necessary indicators such as
material consumption waste generation percentage re-use amount and embodied energy indicators
can be calculated from this analytical study (For more information about indicators resources please
see Annex 1-A) Table 4 6 - First hand data over literature
A simple calculation is needed and that is dividing the CO2 emission Material
consumption and Embodied energy used amounts in Aye project on 63 apartment units with the
same area of 625 as main case in Hammads residential flat ldquoWaste amountrdquo ldquore-use of elementsrdquo
and ldquoembodied energy savedrdquo can be applied on the main case because of similarity of material
choices
IndicatorsAltertanives TRC PSM PCM PTM
Cost stability 6 9 8 9
Time stability 6 9 8 9
Recycleability of elements 3 8 7 9
Protection level 2 9 9 9
Job stability 5 8 8 8
New job creation 3 8 8 8
Quality satisfaction 5 9 8 9
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
70 | P a g e
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow)
bull Prefabricated Timber Modules indictors (PTM)
As it can be seen in table 48 there are no enough data over literature in many areas and due
to the necessities for this study a range of calculations and estimation have to be made based on the
similarity of projects among study cases and survey information Table 4 8 - First hand data over literature
Starting with Cost of the project which an ldquoestimationrdquo based on literature review information
and qualitative comparisons (John quale 2012) (Lu Aye2011) that is approximately 45000 AUD
because it proved that the cost of Timer modules is even cheaper than Steel Modules due to simplicity
of material choice and structure design The schedule of PTM building is shorter than the other
alternative because of numbers of reasons such as less weight of elements which can lead to faster
transportation loading and offload in assembly process on-site In addition the manufacturing lines
are simpler than other modular alternatives because of high repetitions and simplicity in design
For ldquocarbon emissionrdquo and ldquomaterial consumptionrdquo Aye project was used by diving on 63
apartment units which have the same area of 625 m2 as main case In terms of ldquowaste generationrdquo a
unique article was used (by Doyoon 2008) which did a LCA study on Timber modular building and the
amount of wastematerial consumed was about 9 The Noise level and Injury risk can be applied
from other modular alternative because of similarity of construction activities and equipment used
for fabrication Energy utilized during construction of Timer modules have the minimum amount in
comparison with other alternatives because of simplicity of material choice and design enhancement
so that was estimated 80MJ which is slightly less than steel modules with 86 MJ
Re-use of elements in timber modular elements was confirmed by survey among the
constructors over than 70 with a life span of 50 years Embodied Energy used was collected from
Aye case study dividing on 63 apartments units as same as other cases which equals to 65671 GJ
(Table 49) Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue)
bull Prefabricated Concrete Modules indicators (PCM)
The least focus on modular alternative was on Concrete Modules which is because of few uses
that this method has among the projects Balasbaneh study focused on a comparison between Steel
modules and Concrete modules in total project cost and LCA Table 4 10 - First hand data over literature
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury risk Energy utilized Re-use Embodied energy Emb saved
Aye 2500000 996 356 41373 691
Quale 13600
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 45000 20 39375 1580952 9 645 163 80 70 65671 691
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Balasbaneh 239380 8264
Units MLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
71 | P a g e
However the currency of this economic analysis is not as AUD (Australian Dollars) as the main
study Therefore to calculate the cost and CO2 footprint corresponding to main study case a ratio
was obtained between concrete modules amounts and steel modules in Balasbaneh study and then
multiplied to the steel modules quantities in Hammadrsquos main case and resulted project cost of
5188603 AUD and 46442 kg of CO2 emissions
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM alternatives
239380 divide 222580 = 1075478 119862119900119904119905 119903119886119905119894119900 (Balasbaneh study case)
482446 times 1075478 = 5188603 119860119880119863 Total project cost of PCM
8264 divide 9623 = 085877 1198621198742 119903119886119905119894119900
54079 times 085877 = 46442 119896119892 CO2 of PCM
The time indicator was estimated based on steel modules but with this difference that
concrete modules weight more than steel ones so that puts pressure on the transportation and
assembly phases and causes delays in the schedule as a result 24 days was predicted to finish the
project
There is no available information on the literature with specific quantitative details however
based on the qualitative structural information prefabricated concrete modules PCM because of their
similarity of material choice to conventional model have a massive material use in comparison with
Steel and Timber alternatives so that an estimated total material consumed of 20000kg assigned for
this indicator (Aye 2011) (Balasbaneh 2020)
Waste generation have a higher ratio in this alternative because of material choices which
generate more waste than other modular alternatives With this fact in mind the waste ratio
considered slightly more than steel kind with 10 (Aye 2011)
Noise level and Injury risk can be applied from other types because of similarity of equipment
and construction activities in all three modular alternatives (Hammad 2019)
Energy utilized during construction in PCM Alternative can be estimated more than steel ones
because of types of materials used in these modules and their high weight with value of 90MJ (Aye
2011)
The structural elements are ldquonotrdquo built in material which have a high recyclability potential so
that decreases the Re-use ratio to 20 approximately in comparison with other modular alternatives
(Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
72 | P a g e
Embodied energy used amount and its potential saving have the minimum value in a
qualitative comparison with other alternatives which respectively values of 800GJ and 60 were
estimated for them (Aye 2011) Table 4 11 - Final indicators for PCM
bull Traditional Reinforced Concrete (TRC) final indicators
The highest focus over the literature is to make a comparison between one of the modular
options and a traditional method which results more availability for direct data for Traditional method
The main case study is not an exception with almost half of the value are available directly such as
Project cost Time Noise level Injury risk and Energy utilized during construction which are shown in
green at table 412 (Hammad 2019) Table 4 12 - TRC first-hand data over literatures
Nevertheless still there are values that must be calculated over literature Green gas emission
indicator and Embodied Energy used were calculated form Ayersquos case study by dividing the values on
63 apartment units which results 3620635kg Co2 emission and 6033 GJ of 625 m2 area as same as
main case study (Aye 2011) (Hammad 2019)
Material consumption have the same methodology as carbon footprint with final value of
626825kg which is massively higher from modular alternatives (Aye 2011) (Hammad 2019)
Waste generation was calculated qualitatively from a literature resource called ldquoModular
Construction for Multifamily Affordable Housingrdquo by WSP which acclaims that the conventional site-
built method produces around 25 times more construction waste (WSP 2018) Thus TRC waste
generation is more than 25 times of modular ones with the value of 15
Two values of Re-use and Embodied energy saved by Re-use of elements were obtained from
Ayersquos case study respectively 22 and 322 (Aye 2011) Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow)
In general the table 414 shows the References and final indicator values that were used for decision
making process (Direct data are shown in Green Calculated data in yellow and estimated data in
blue)
Table 4 14 - Final Quantitative indicators used for decision making process
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 812298 6598 71 217 198
Akbarnejad 120000 67 84672
Aye 2281000 3949 22 38008 322
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
PSM 482446 2131 54079 138254 5 645 163 8593 50 9012 813
PTM 45000 20 39375 1580952 9 645 163 80 70 65671 691
PCM 5188603 24 46442 20000 10 645 163 90 20 800 60
TRC 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrence Ham Aye Balas Hammad Balas Aye Aye Doyoon WSP Aye Hammad Hammad Hammad Aye Aye Aye
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
73 | P a g e
Weights
The Weights (Pesos in MIVES) which are one of the most important factors in decision making
process have be assigned on the data in a way that the priority of each section in terms of efficiency
and importance can decide which value will have among the others AHP method was used to assign
weights on the data In AHP you get the weights through the subjective importance of each element
with respect to the others (Alejandro Josa 2012)
bull Weights of requirments
The importance of requirmenets was assumed based on proffessional survey among
constructors architects sales agents and clients in order to know the demands of market and make
the decision rely on what market expects from a innovative method According to the survey time
reduction is the first priority for choosing the modular methods by constructors and future clients so
than acheived 30 of weight Economic issues came after the time factor because of unconsistency
between responds about cost saving on the budget or offseting the expenses gap by tarnsportation
extra costs on the project Economic requirement has 27 of weight In some regions the priority of
choosing an innovative method are environmental emissions waste generation and recycleability of
products Therefore environmental requirement came after the economic one with 25 of weight
As it mentioned before Social and safety advantages are included in this decision making
process with respectly weights of 13 and 5 because of their less priorities among clients and market
players Table 4 15 - Requirement weights
Requirement Economic Time Environmental Safety Social
Weights 27 30 25 13 5
bull Weights of criteria
In cost and time of project which are single criteria have 100 of weights However for
instance in environmental and AHP method must be used to assign the weights based on the
importance in an environmental consideration The amount of emission that construction activities
can produce and the amount of negative effect on the global environment have been considered for
AHP method in weight assignment process Energy consumption and material consumption have the
priority to consider in LFA analysis because the consumption of primary resources have to be
minimized in a project at the first step and then the emission have to be reduced by changing the
processes etc Finally the ability to re-use and recycle and elements must be improved (Mohammad
Kamali 2017) (John Quale 2012) (Marta Gangolells 2014) Therefore Energy Consumption and
Material consumption have the most weight of 17 Embodied energy with 16 and waste generation
Greenhouse Gas emission and Recycle achieved 15 of weight At last noise Pollution took the least
priority of weights with 5 Table 4 16 - Weights of criteria
bull Weights of Indicators
Both of Economic and Time indicators divided to two sub-categories project cost and time and
their stability ratios with 80 and 20 weights by AHP method
Criteria that are single indicator obviously have 100 of weights However there are two
indicators in recycle criteria Recyclability and Re-use of elements with 40 and 60 weight
respectively Moreover Embodied Energy have is divided to Embodied energy used which is more
CriteriaEnergy
consumption
Waste
generation
Material
Consumption
Noise
pollution
Greenhouse
gas emissionRecycle
Embodied
energy
Weights 17 15 17 5 15 15 16
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
74 | P a g e
important than the other that is saving in embodied energy by re-use because as it mentioned before
in the first place the use have to be minimized and then actions such as re-use of elements have to be
done 70 of weight for Embodied energy use and 30 for Saved Embodied energy are assigned Job
stability and New job creation with weights of 50 each are the Job status indicators (Figure 411)
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software
Value function play an important role on deciding which comparative final value can each
indicator have among the other indicators for each alternative To evaluate the sustainability index
(Is) of each alternative solution value functions assigned and were used (Alarcon et al 2011) The
generic form of a value function is represented by Table 417 which allows to assess the sustainability
(satisfaction) associated with each indicator by transforming the physical units to a dimensionless
value between 00 and 10
Equation 4 1 - Functionality of value function elements
In Eq (41) B is the value of indicator(Iind) for Xmin Xmin is the minimum abscissa value in the
indicator interval assessed X is the abscissa value for the indicator assessed Pi is a shape factor which
defines whether the curve is concave (Pi lt 1) convex (Pi gt 1) linear (Pi = 1) or S-shaped (Pi gt 1) (see
figure 412) Ci approximates the abscissa at the inflexion point Ki tends towards (Iind) at the inflexion
point B the factor that prevents the function from exceeding the range (0 1) is obtained by Eq (42)
Xmax being the abscissa value of the indicator that gives a response value of 1 for increasing value
functions
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
75 | P a g e
Equation 4 2 - B value equation
Figure 4 12 - Possible forms of the value function
Due to the lack of existence of resources for assigning the specific value functions for modular
alternatives some hypotheses that can increase the feasibility and sustainability of project were
considered for the shape P K and C values to select the best form of abacus
In the other side maximum and minimum satisfaction points were selected on the
expectations of a project management view For instance in total project cost indicator case
minimum satisfaction point is 82000 AUD that is slightly more than the traditional reinforced concrete
alternative project cost (812298 AUD) because of the fact that those alternatives should be
considered as a reasonable options which can make saving in final budget Moreover the same rule
can be applied for maximum satisfaction point which is close to the Timber Modular alternative (45000
AUD) to minimize the final budget as much as possible The shape of the abacus was selected as
Convex shape (Convexa in MIVES) because even the least economic saving that an alternative can
achieve have a positive effect on the satisfaction of project and can be given any positive points in a
scale of ldquo0 to 10rdquo But the more the curve closes to the traditional alternative budget the les
satisfaction it can receive (Figure 413)
Figure 4 13 - Value function for total project cost in MIVES
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
76 | P a g e
The following Table 417 includes the value functions which were used for the rest of the
indicators Table 4 17 - Value function for indicators in MIVES
Data analysis
Indicators Values
Indicator data were translated to general normalized values shown in Table 418 amp 419 based
on the given value functions that earlier assigned This step is crucial for next analyses which will be
done to result the criteria and requirement values which lead to sustainability Indexes that can take
the multi-criteria decision As it can be seen these values have the same range of 0 to 1 so that can be
compared in with a common unit Comparisons are obvious in this level because of single value
orientation of each indicator however on following analysis there will be multi-criteria comparisons
which can achieve useful data for future decision-making process Table 4 18 - Indicators normalized values
Table 4 19 ndash Indicator normalized values
Indicators Lower limit Upper limit Max satisfaction Min satisfaction P K C Shape
Total Project Cost 30000 90000 43000 82000 05 05 79900 Concave
Cost stability 0 10 10 5 05 05 55 Concave
Total Project Time 20 75 20 68 05 05 632 Concave
Time stability 0 10 10 5 05 05 55 Concave
Energy Utilized 75 220 80 205 05 05 1925 Concave
Solid Waste 0 100 0 18 08 05 162 Concave
Material Consum 10000 70000 12000 63000 05 05 57900 Concave
Noise Level 58 78 62 72 05 05 71 Concave
CO2 32000 60000 32000 55000 05 05 52700 Concave
Recyclability 0 10 10 0 05 05 1 Concave
Re-use 0 100 60 0 05 05 20 Concave
Embodied energy 600 950 600 915 05 05 8835 Concave
Embodied saved 0 100 90 30 05 05 36 Concave
Injury risk 0 4 155 22 05 05 2135 Concave
Protection level 0 10 10 0 1 001 1 Lineal
Job stability 0 10 9 4 1 001 45 Lineal
New job creation 0 10 10 0 05 05 5 Concave
Quality Satisfaction 0 10 10 0 1 001 5 Lineal
R1C1I1 R1C1I2 R2C1I1 R2C1I2 R3C1I1 R3C2I1 R3C3I1 R3C4I1 R3C5I1
TRC 016 051 024 051 027 029 01 034 092
PSM 094 092 098 092 098 082 099 088 023
PCM 09 081 097 081 097 059 093 088 065
PTM 098 092 1 092 1 064 097 088 085
R3C6I1 R3C6I2 R3C7I1 R3C7I2 R4C1I1 R4C2I1 R5C1I1 R5C1I2 R5C2I1
TRC 073 026 1 024 024 021 02 063 05
PSM 095 094 023 095 094 09 08 092 09
PCM 092 068 064 077 094 09 08 092 08
PTM 098 084 092 085 094 09 08 092 09
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
77 | P a g e
Criteria Values
MIVES analysed each criterion by single or multi-indicator normalized values and resulted
values with a same range of 0 to 1 for following comparisons Table 4 20 - Criteria normalized values
Table 4 21 - Criteria normalized values
To begin with Project Cost (R1C1) criteria values shows that Almost three modular
alternatives performed 3 times more than the traditional method positively caused by hugely less total
project cost (R1C1I1) and great cost stability (R1C1I2) in project final budget The minimum value
belongs to PTM with 097 and slightly more than PSM and PCM is the next alternative with a value of
088 and at last TRC with 023 (Figure 414)
Figure 4 14 - Criteria normalized values
The comparison between modular alternatives in terms of which one can save time on the
schedule is close and it can be said that all three can make the project executed more than 3 times
shorter than traditional approach Timber steel and concrete options with respectively 098 097 and
094 values were compared to the conventional concrete method with 029 value (Figure 415)
R1C1 R2C1 R3C1 R3C2 R3C3 R3C4
TRC 023 029 028 029 009 032
PSM 094 097 099 083 099 088
PCM 088 094 096 059 094 088
PTM 097 098 101 064 096 088
R3C5 R3C6 R3C7 R4C1 R4C2 R5C1 R5C2
TRC 091 045 083 024 021 040 052
PSM 024 096 048 095 090 088 092
PCM 064 077 072 095 090 088 080
PTM 085 091 096 095 090 088 092
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
78 | P a g e
Figure 4 15 - Project Schedule
ldquoEnergy saving potentialrdquo in modular methods are close to the maximum satisfaction point
with timber solution and steel modules while concrete option is on the chase with 096 While
Traditional alternative only have 28 of satisfaction level
ldquoWaste generationrdquo among the alternatives have a different attitude while traditional method
with value of 029 has the most ratio of material waste production modular alternatives are
performing better where steel option have the most reduction with value of 083 and follow to that
timber and concrete options respectively 064 and 054 values PCM alternative as it said before
because of similarity of material choice to TRC have the minimum performance among the other
three (Figure 416)
Figure 4 16 - Waste generation ratios
ldquoMaterial consumptionrdquo criteria are dominated by modular methods which have a high
satisfaction with over than 09 normalized values while TRC performance can be concerning for the
primary resources with 01 normalized value
Previously on this report the fact was mentioned that off-site construction can benefit the
environment with noise reduction during construction activities based on literatures and this study
confirms this advantage by 088 values of all three modular alternatives and 032 value of traditional
RC which is less than half of modular options
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
79 | P a g e
A highlight of this study is about the comparison of CO2 Emissions of alternatives during the
constructionfabrication activities which traditional method have the minimum contamination with a
value of 091 and follow to that Timber option with 085 which is close to the TRC method Later to
that Concrete modules have a value of 064 and the minimum satisfaction belongs to the steel
modules with 024 normalized value This result bring uncertainty to the fact that modular
construction can reduce the Greenhouse gas emission to 30 over the literature review
Figure 4 17 - CO2 Emission normalized values
This study shows that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options with a value of 096 because of the material choice
repetition in element manufacturing and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution have 091 value that can confirm the concept of
recyclability for wooden modules which was mentioned by participants in professional survey as well
Figure 4 18 - Recyclability and re-use potential of alternatives
There is a discussion about the amount of embodied energy used during the lifetime of each
alternative and the potential of future saving by re-use of elements in projects which effect the total
embodied energy consumption in construction
As the Figure 419 explains traditional method has the maximum satisfaction level in terms
of consumption while steel modules have the least satisfaction of life cycle embodied energy used of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
80 | P a g e
023 PTM have a better value of 091 which shows that Timber solution can be reliable among the
others
However this study resulted that the most re-use value belongs to steel option with 095
value that and other two timber and concrete modules respectively with 085 and 077 can
compensate the gap with traditional method that has only 024 Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction total value of 096 Later
traditional reinforced concrete method with 088 still proves its abilities over other two modular
alternatives
Figure 4 19 - Embodied energy consumption and saving potential by reuse
In terms of safety modular alternatives because of their off-site nature can provide a high
satisfaction level with values of 095 in injury risks for workers and 090 protection from nature causes
which confirms the theory of safety advantage of modular construction over traditional methods from
literature studies (Figure 420)
Figure 4 20 - Safety advantage of modular construction over traditional method
Social benefits which were mentioned in literature review section also had been examined in MIVES
system and the job stability and job creation in modular construction can benefits the construction
society in significant way among the regions that have employability ratio problem
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
81 | P a g e
Figure 4 21 - Social criteria
Requirement Values
After analysis on criteria functions general values of each requirement were related to
alternatives achieved which can examinate all four construction methods to know which option is
more suitable in terms of Economic time environmental safety and social issues
The Table 422 below demonstrates the Requirements normalized values for each alternative Table 4 22 - Requirement normalized values for four indicators
bull Economic and Time requirements
As the graph illustrates Modular methods have a significant performance in economic and
time terms with the maximum values of 097 and 094 in Time and 098 and o97 in Economic
requirement for Timber and then Steel modules-based methods respectively Traditional reinforced
concrete option showed a poor functionality in cost and time of project with minimum values of o29
and 023 in order (Figure 422)
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values analysed by MIVES
Requirements Economic Time Environmental Safety Social
TRC 023 029 045 022 046
PSM 094 097 075 093 088
PCM 088 094 078 093 084
PTM 097 098 088 093 088
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
82 | P a g e
bull Environmental requirement
Generally all three modular approaches have beaten the traditional method with almost
double of normalized values in comparison
Despite the poor performance of steel modules in Greenhouse gas emissions and Embodied
Energy used in construction in total numbers proved that can provide the environmental demands
better than traditional option with a value of 075 which is third modular alternative in overall
Prefabricated Timber modules obtained the maximum value of 088 which claims not only
most economic option but environmentally friendly among other relatives and following to that
Concrete modules with value of 078 shows its liability to be chosen in case of need while the
traditional concrete method which includes most of the used materials n PCM but in a on-site plant
only can achieve a satisfaction value of 045 among the others (Figure 423)
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind
bull Safety and social requirements
The dominance of Modular construction in safety and social requirements over conventional
option can be seen in Figure 424 which can raise the possibility of modular methods to be the best
decision over the traditional option to construct this residential project As it was mentioned before
these two criteria must be considered in any decision-making process because of their high
importance in construction industry
Figure 4 24 - Modular dominance in safety and social requirements over conventional option
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
83 | P a g e
Sustainability Values (Final decision)
Finally the sustainability Indexes can be obtained to claim which alternative will be decided
as the most sustainable option for the main studyrsquos project to be build The needs of market such as
short project schedule cheaper budget reduction in environment emissions and ability to
recyclereuse safety measures and social benefits put effects on this decision as previously
mentioned
Table 423 explains that Prefabricated Timber Modules (PTM) is most sustainable alternative
among the other with a perfect normalized value of 094This could be because of its shorter schedule
of construction lowest total budget and excellency in environmental performance among the other
alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative Table 4 23 - SI (Sustainability Indexes related to four alternatives)
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This fact explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives
TRC PSM PCM PTM
SI 032 090 088 094
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
84 | P a g e
5 Conclusions Decision making process
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria etc However to find out how much practical these benefits are in the market several trade-
offs must be done by professional tools such as project management software programs which can
take decisions based on the input data that receive MIVES software was used in this study to
examinate these benefits The resources for this type of studies are limited due to the lack of focus or
newfound nature of this subject and only five of them were selected because of their variety of their
criterion studies reliability and accuracy of data Requirements criteria indicators and weights that
were used in MIVES had been selected based on demands of market and professional opinions
received from the survey and availability of data over references After assigning the value functions
which are related to satisfaction level on each criterion (For instance cost reduction time saving and
minimization of emissions) normalized values were achieved that can be compared between
alternatives with range of 0 to 1
Conclusions and discussion
ECONOMIC ndash TIME discussion
bull Decision-making result
Generally all three modular alternatives have beaten the traditional method with almost
double of normalized values Modular methods had a significant performance in economic and time
terms with the maximum values in Time and Economic requirements for Timber and then Steel
modules Traditional reinforced concrete option showed a poor functionality in cost and time of
project with minimum values
Literature reviews information
These Results confirm the 50 of time saving in projectrsquos schedule (McKinsey amp Company
report 2019) and 20 of cost reduction on the budget which was mentioned also in numbers of
literatures
Professional survey confirmation
In addition the claims from professional participants in survey about the 50 cost reduction
due to the added value of every hour of work in comparison with traditional stick and build on-site
method can be approved even far more those expectations
ENVIRONMENTAL discussion
bull Recyclability and re-use potential
This study showed that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options because of the material choice repetition of
elements in manufacturing line and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution can confirm the concept of recyclability for wooden
modules which was mentioned by participants in professional survey as well
bull Embodied energy used and saving by re-use
There is a discussion over the literature and survey participants about the amount of
embodied energy used during the lifetime of each alternative and the potential of future saving by re-
use of elements in projects which effect the total embodied energy consumption in construction
where one of the companies acclaims that ldquoour homes are not positive in energy consumption
aspectrdquo Traditional method has the maximum satisfaction level in terms of consumption while steel
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
85 | P a g e
modules have the least satisfaction of life cycle embodied energy used PTM have a better value of
091 which shows that Timber solution can be reliable among the others However this study resulted
that the most re-use value belongs to steel option and other two timber and concrete modules
respectively can compensate the gap with traditional method Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction Later traditional reinforced
concrete method still proves its abilities over other two modular alternatives
bull Greenhouse gas emission
Despite the poor performance of steel modules (PSM) in Greenhouse gas emissions that bring
uncertainty to the fact that modular construction can reduce the Greenhouse gas emission to 30
over the literature review and Embodied Energy used in construction proved that can provide the
environmental demands better than traditional option which is third modular alternative in overall
comparison
bull Most environmentally friendly alternative
Prefabricated Timber modules obtained the maximum value which achieves not only most
economic option but environmentally friendly among other relatives Following to that Concrete
modules shows its liability to be chosen in case of need while the traditional concrete method which
includes most of the used materials of PCM but in an on-site plant only can achieve the minimum
value
Comparison with literature review information and survey outputs
This comparison explains the truth about the concept of being environmentally friendly about
modular construction that have been mentioned in various scientific articles (McKinsey amp Company
report 2019) (M Kamali 2016) and the survey results which confirmed the concept in real cases at
the market over years of experience
SAFETY AND SOCIAL dominance by modular methods
The dominance of Modular construction in safety and social requirements over conventional
option was resulted which can raise the possibility of modular methods to be the best decision over
the traditional option to construct this residential project As it was mentioned before these two
criteria must be considered in any decision-making process because of their high importance in
construction industry Social benefits which were mentioned in literature review section also had been
examined in MIVES system and the job stability and job creation in modular construction can benefits
the construction society in significant way among the regions that have employability ratio problem
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES
Prefabricated Timber Modules (PTM) is most sustainable alternative among the other with a
perfect normalized value of 094This could be because of its shorter schedule of construction lowest
total budget and excellency in environmental performance among the other alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This result explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
86 | P a g e
Effective external factors on decision
The decision was made for the best alternative in terms of sustainability for a specific
residential case located in Sydney Australia among three modular options and one traditional
method However there are factors which can affect the final decision obviously Such as the location
of the project which the availability of primary resources can change the or alternatives or number of
indicators The local market and their demands for specific products can be crucial for choosing the
best method which affect the priorities of weights Regulation of every regions as it was mentioned
before can change the project requirements and indicators
The type of the project was a residential building that has its own characteristics but for
instance a school or hospital project would demand a higher functionality and lifetime because of their
distinctive operation kind and evidentially can be considerable in decision-making process to the end
step Special project due to their unique requirements often do not consider all criterions For
instance emergency health stations demanded during the Virus pandemic period have their own
material choose design enhancement and priorities on requirements
Future studies
Due to novelty of this subject there are numbers of studies still remained without coverage
which might be studied in future
Decision making study on two real projects with the input data of professional
modular and traditional constructors
Due to the lack of information over literature there were so many elements that have been
estimated by hypothesis and survey information therefore it is crucial to find these data in order to
do a precise study with real numbers These data can be obtained by requests to industry players to
have access of real project details including budget schedule material consumptions etc By this
action the liability of the study can be improved and accurate results can be achieved Thus a
decision-making process can be done to find out which alternative can be more sustainable
Technological studies about the production line of a modular off-site plant by factory
and on-site visits
There are still uncertainties about the status of use of automation productivity rate etc which
have to be analysed closely Modular construction was suggested as an example of industrialization in
construction industry to improve the productivity rate but corresponding to past survey the majority
of constructors are not benefiting from automation in their production lines and assembly processes
A study is needed on different phases of a project that have to be monitored and analysed scientifically
in order to find challenges errors and possible solutions to make this method even more sustainable
A survey about challenges in modular construction and its possible solutions to find
adequate solutions
Challenges have to focused more on this method because its players are still suffering from
the incompatibility of construction industry and the projectrsquos old conditions with innovative solutions
Series of interviews with experts factory visits etc have to be done to hear the voices of them and
then researchers to find solutions to update the industry and help them for growth
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
87 | P a g e
Recommendations
Cooperation between industrial players and scientific researchers in offsite
construction
Numbers of contrasts where found in the data and results among literatures professional
participants of survey and the decision-making study which shows a poor status of cooperation
between scientific researchers and professional players in the construction industry It is obvious that
the real data from the constructors designers etc in real projects are more reliable than scientific
estimation which in this case were based on BIM models and approximate calculations without any
interruption effects of common challenges in industry There were few participants who did not want
to share their project details in public or even education purposes or in a case one of the most
innovative players in modular industry responded their lack of available time to respond the survey
by direct email These attitudes can increase the gap between two vital elements for improvement
which are science and industry in construction society and to reduce it cooperation must be increased
specially in off-site society
Education about industrialization in construction and its alternatives
The idea of lack of education among engineers and architects who enter the professional
society about off-site construction methods was proved by the collected information from survey
participants which can cause problems in the projectrsquos design coordination and execution processes
These series of errors must be resolved by updating the education resources about innovative
methods such as off-site construction industrialization in construction concept rather than traditional
on-site methods that still occupy most of the educational courses these actions can improve the
common challenges in construction industry such as productivity problem and sustainability rate by
encouraging the researchers even far beyond the boundaries of investigations and make the way
possible to find more innovative solutions such as robotic fabrication 3D concrete printing etc
Establishing international and regional adequate codes
Use of automation is suggested by the researchers and industry players to raise the
productivity and sustainability in construction as the other industries which resulted positively
However constructors and manufacturers are suffering from a lack of exitance of international united
codding for their production line and boundaries and uncertainties by local regulations
To resolve these issues participants addressed an international code similar to what on-site
traditional methods have which the responsibility of creation of these codes are on the shoulders of
researchers and professional experts with a mutual partnership that is only possible with cooperation
of industry with science as it mentioned before
Synchronizing the contract conditions with modular construction conditions
There are numbers of problems in terms of contract conditions such as misunderstanding by
final client who is the end home buyer who ldquobelieves the factory to be the builder and the actual
independent builder to be a sales agent for the factoryrdquo one of the participants mentioned A
recommended solution for this problem is to define the relationships between the participants of
projects their responsibilities For instance requiring the builders customer to sign a disclosure
acknowledgement from that describes the relationship in detail In addition there is a lack of quality
partners on site The problem starts when on-site participants realize the advantages of modular
construction they tend to increase their prices for services which can increase the final prices of
project Another challenge which modular projects can face is the lack of delivery of project on agreed
time with an unacceptable quality of on-site execution The professionals answered that the
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
88 | P a g e
responsibility of ensuring that the work is done properly belongs to the builder which any ldquodelays in
this can result in postponed transport of product and interest through demurrage chargesrdquo
These problems must be solved by defining unique types of contracts that are adapted with
the off-stie construction nature and be obeyed by all the participants globally
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc
The only value that the market considers choosing modular method over traditional
construction is to be cheaper while majority of people the media and even professional engineers do
not understand the capabilities of modular construction Many people continue to confuse this form
of construction with HUD on frame products Another wrong perception that the publicmarket
believes is that the prefabrication methods limits the design options while some players believe that
the reverse is the case Therefore by using one of the main advantages of modular construction which
is shorter schedule the market can be dominated by modular projects and the more cases they
deliver the more recognised this method would be among the public and at the end the superior
nature of modular approach can be proved Another solution is a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Many of these wrong perception and misunderstandings can be
clarified by well-organized advertisements about several advantages that modular construction have
in comparison with conventional methods
Changes in financial strategies and adapting them with off-site construction nature
Financial assists which are crucial for kind of projects that are dependent to these aids are
not harmonized with modular project processes where there are argues that until the first deliveries
of elements to the site location and their assembly these aids will not be reachable This issue creates
pressure on cash flow of project where bank finance is involved Changes in contract conditions and
education for financial supporters are recommended solutions to improve the partnerships in
projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
89 | P a g e
6 References 1) Balasbaneh AT Ramli MZ A comparative life cycle assessment (LCA) of concrete and
steel-prefabricated prefinished volumetric construction structures in Malaysia Environ Sci
Pollute Res (2020) httpsdoiorg101007s11356-020-10141-3
2) Doran D and Giannakis M (2011) An examination of a modular supply chain a
construction sector perspective Supply Chain Management Vol 16 No 4 pp 260-
270 httpsdoiorg10110813598541111139071
3) Lawson RM Ogden RG Bergin R 2012 Application of modular construction in high-rise
buildings Journal of Architectural Engineering httpsdoi101061(ASCE)AE1943-
55680000057
4) Diez R et al (2007) lsquoAUTMOD3 The Integration of Design and Planning Tools for Automatic
Modular Constructionrsquo International Journal of Advanced Robotic Systems httpsdoi
1057725671
5) Lee J Park M Lee H ampamp Hyun H (2019) Classification of Modular Building
Construction Projects Based on Schedule-Driven Approach Journal of Construction
Engineering and Management 145(5) 04019031 httpsdoi101061(asce)co1943-
78620001656
6) Barbosa F Woetzel J Mischke J Ribeirinho M Sridhar M Parsons M Brown S
(2018 July 09) Reinventing construction through a productivity revolution Retrieved
September 28 2020 from httpswwwmckinseycomindustriescapital-projects-and-
infrastructureour-insightsreinventing-construction-through-a-productivity-revolution
7) Quale J Eckelman MJ Williams KW Sloditskie G and Zimmerman JB (2012)
Construction Matters Comparing Environmental Impacts of Building Modular and
Conventional Homes in the United States Journal of Industrial Ecology 16 243-253
httpsdoi101111j1530-9290201100424x
8) Horwitz-Bennett Barbara (2020) Rising to the challenge sl Modular Building Institute
(MBI)
9) Lu N amp Korman TM (2010) Implementation of Building Information Modeling (BIM) in
Modular Construction Benefits and Challenges
10) Institute Modular Building 2019 Permanent Modular Construction Canada Modular
Building Institute
11) Josa A (2012) Introduccioacuten a MIVES y el anaacutelisis multicriterio Jornada sobre la Importancia
de un meacutetodo para la toma de decisiones modelo MIVES para una ingenieriacutea sostenible
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
90 | P a g e
12) Aye L Ngo T Crawford R H Gammampila R amp Mendis P (2012) Life cycle greenhouse
gas emissions and energy analysis of prefabricated reusable building modules Energy and
buildings 47 159-168
13) Kamali M amp Hewage K (2016) Life cycle performance of modular buildings A critical
review Renewable and sustainable energy reviews 62 1171-1183
14) Lawson M Ogden R Goodier C (2014) Design in Modular Construction London CRC
Press httpsdoiorg101201b16607
15) Generalova E M Generalov V P amp Kuznetsova A A (2016) Modular buildings in modern
construction Procedia engineering 153 167-172
16) Thompson J (2019) Modular Construction A Solution to Affordable Housing Challenges
Cornell Real Estate Review 17(1) 21
17) Modular construction for multifamily affordable housing (2018) WSP
httpscdnymawscomwwwnibsorgresourceresmgrosccepa-modular-construction-
forpdf
18) Hammad A W A amp Akbarnezhad A (2017) Modular vs conventional construction a
multi-criteria framework approach In ISARC Proceedings of the International Symposium on
Automation and Robotics in Construction (Vol 34) IAARC Publications
19) Ferdous W Bai Y Ngo T D Manalo A amp Mendis P (2019) New advancements
challenges and opportunities of multi-storey modular buildingsndashA state-of-the-art review
Engineering Structures 183 883-893
20) Bertram N Fuchs S Mischke J Palter R Strube G amp Woetzel J (2019) Modular
construction From projects to products McKinsey amp Company Capital Projects amp
Infrastructure 1-34
21) Hsu P Y Aurisicchio M amp Angeloudis P (2020) Optimal logistics planning for modular
construction using multi-stage stochastic programming Transportation Research Procedia
46 245-252
22) Rausch C Nahangi M Perreault M Haas C T amp West J (2017) Optimum assembly
planning for modular construction components Journal of computing in civil engineering
31(1) 04016039
23) Connor G Jones C E amp Finney S J (2014) Easing future low voltage congestion with an
AC chopper voltage regulator httpsdoi 101061(ASCE)CO1943-78620001001
24) Ahn Y H amp Kim K T (2014) Sustainability in modular design and construction a case
study of lsquoThe Stackrsquo International Journal of Sustainable Building Technology and Urban
Development 5(4) 250-259
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
91 | P a g e
25) Gunawardena D Mendis P Ngo D Aye L amp Alfano J (2014) Sustainable prefabricated
modular buildings httpsdoi 10131402148473920
26) Olearczyk J Al-Hussein M Bouferguene A amp Telyas A (2009) Virtual construction
automation for modular assembly operations In Construction Research Congress 2009
Building a Sustainable Future (pp 406-415)
27) Woźniak-Szpakiewicz E (2016) EU migrant crisis and increasing demand for modular
construction modular social housing complex for refugees in Munich In Back to the Sense
of the City International Monograph Book (pp 921-931) Centre de Poliacutetica de Sogravel i
Valoracions
28) Wunderlich-Malec 2019 The Modular Solution to Reduce Total Construction Costs
httpswwwslidesharenetJoelGil2wuderlich-malec-engineering-modular-construction
29) HAMMAD AWA AKBARNEZHAD A WU P WANG X and HADDAD A 2019 Building
information modelling-based framework to contrast conventional and modular construction
methods through selected sustainability factors Journal of Cleaner Production [en liacutenea] vol
228 pp 1264ndash1281 ISSN 0959-6526 DOI httpsdoiorg101016jjclepro201904150
Disponible en httpwwwsciencedirectcomsciencearticlepiiS0959652619312296
30) HONG J SHEN GQ LI Z ZHANG B and ZHANG W 2018 Barriers to promoting
prefabricated construction in China A costndashbenefit analysis Journal of Cleaner Production
[en liacutenea] vol 172 pp 649ndash660 ISSN 0959-6526 DOI
httpsdoiorg101016jjclepro201710171 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS0959652617324782
31) LOPEZ D and FROESE TM 2016 Analysis of Costs and Benefits of Panelized and Modular
Prefabricated Homes Procedia Engineering [en liacutenea] vol 145 pp 1291ndash1297 ISSN 1877-
7058 DOI httpsdoiorg101016jproeng201604166 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS1877705816301734
32) NEELAMKAVIL J 2009 Automation in the Prefab and Modular Construction Industry [en
liacutenea] Sl sn DOI 1022260ISARC20090018 Disponible en
httpwwwiaarcorgpublicationsproceedings_of_the_26th_isarcautomation_in_the_pref
ab_and_modular_construction_industryhtml
33) SANTIAGO M ALBERTO J MARIA NJ and PATRICIA G 2008 Building industrialization
robotized assembly of modular products En M ONORI (ed) Assembly Automation [en
liacutenea] vol 28 no 2 pp 134ndash142 ISSN 0144-5154 DOI 10110801445150810863716
Disponible en httpsdoiorg10110801445150810863716
34) McGeorge D amp Zou P X (2012) Construction management new directions John Wiley amp
Sons
35) Fieldwire (2018) Why the Construction Industry Is Stuck in the Past
httpswwwfieldwirecomblogis-construction-stuck-in-the-1960s
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
92 | P a g e
36) Construction industry - Office for National Statistics (2019) ONS
httpswwwonsgovukbusinessindustryandtradeconstructionindustry
37) Timmer M P O Mahony M amp Van Ark B (2007) EU KLEMS growth and productivity
accounts an overview International Productivity Monitor 14 71
38) Smith A (2011 September 22) Agile and Lean for Construction SlideshareNet
httpswwwslidesharenetadrianlsmithagile-and-lean-for-construction-9384237
39) The massive opportunity of digitization in Engineering amp Construction (2019)
JourneyappsCom httpsjourneyappscomblogmassive-opportunity-digitization-
engineering
40) Tapscott D amp Tapscott A (2018) Blockchain Revolution How the Technology Behind
Bitcoin and Other Cryptocurrencies Is Changing the World (Reprint ed) Portfolio
41) Can Blockchain Fix the Construction Industryrsquos Productivity Problem (2018) Enstoa
httpsenstoacomblogcan-blockchain-fix-construction-industrys-productivity-problem
42) Itanola M (2019 June 5) Hey Quantity Surveyor is BIM going to take your job Blaze
Threads httpswwwblazethreadcomhey-quantity-surveyor
43) BIM Community (2017) Remodeling Construction Industry with Digitization BIM and
Reality Capture httpswwwbimcommunitycomnewsload563remodeling-
construction-industry-with-digitization-bim-and-reality-capture
44) Kolarevic B (2003) Digital production Architecture in the digital age design and
manufacturing 38-63
45) Labonnote N Roslashnnquist A Manum B amp Ruumlther P (2016) Additive construction State-
of-the-art challenges and opportunities Automation in construction 72 347-366
46) Kapoutsis A C Chatzichristofis S A Doitsidis L de Sousa J B Pinto J Braga J amp
Kosmatopoulos E B (2016) Real-time adaptive multi-robot exploration with application to
underwater map construction Autonomous robots 40(6) 987-1015
47) Khoshnevis B (2004) Automated construction by contour craftingmdashrelated robotics and
information technologies Automation in construction 13(1) 5-19
48) R Alice (2019) CRYSTAL PALACE SHOWER TALK httpsbloginoxstylecomencrystal-
palace
49) Eba (2014) HISTORY ldquoballoon framingrdquo the first prefabricated building system (US)
Architecture for the 99 httpslikemyplacewordpresscom20140214history-balloon-
framing-the-first-prefabricated-building-system-us
50) Peter Goumlssel Arnt Cobbers Oliver Jahn (2012) A Brief History of Prefab ArchitectureWeek
httpwwwarchitectureweekcom20121003design_1-1html
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
93 | P a g e
51) Merin G (2018) AD Classics Habitat 67 Safdie Architects ArchDaily
httpswwwarchdailycom404803ad-classics-habitat-67-moshe-safdie
52) Sveiven M (2018) AD Classics Nakagin Capsule Tower Kisho Kurokawa ArchDaily
httpswwwarchdailycom110745ad-classics-nakagin-capsule-tower-kisho-kurokawa
53) Modular Building Experience | Deluxe Modular (2020)
httpswwwdeluxemodularcomexperience
54) Applications | Modular Construction | Bathroom Pods (2020) Howick Ltd
httpswwwhowickltdcomapplicationsmodular-constructionbathroom-pods
55) Project types (2018) Panel built httpswwwpanelbuiltcomblogmodular-building-types
56) Mobile Mini Merger - WillScot (nd) Willscot httpswwwwillscotcomAboutMobile-
Mini-Merger
57) Teague L (2017) Urbantainer breaks down the negative stereotypes of modular building
Frameweb httpsframewebcomarticleurbantainer-breaks-down-the-negative-
stereotypes-of-modular-building
58) Modular construction (nd) SteelconstructionInfo
httpswwwsteelconstructioninfoModular_construction
59) Modular V (2020) What Is Modular Building Construction Your Ultimate Guide Vanguard
httpsvanguardmodularcomabout-modular
60) Permanent Modular Construction Annual Report 2019 | Modular Building Institute (2019)
MBI httpswwwmodularorgHtmlPageaspxname=pmc-2019-home
61) Modular Construction Foundation (2020) Triumph Modular
httpswwwtriumphmodularcomabout-triumphour-servicesconstruction-
managementfoundations
62) Weights and Dimensions (2020) ITF httpswwwitf-oecdorgweights-and-dimensions
63) Sajip J (2019) Modular Construction A Sustainable Building Method NY-Engineers
httpswwwny-engineerscomblogmodular-construction-a-sustainable-building-
methodWeights and Dimensions (2020 August 28) ITF httpswwwitf-oecdorgweights-
and-dimensions
64) Muresan F (2019) What is Modular Construction NY-Engineers httpswwwny-
engineerscomblogwhat-is-modular-construction
65) ADVANTAGES of using SurePods prefabricated modular bathroom pods (nd) SurePods
httpswwwsurepodscomspeed
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
94 | P a g e
66) EasyPads - The easy-to-use foundation system for modular buildings (2019 March 23)
EasyPads - Foundation System httpseasypadscouk
67) Honrubia M amp Mendonccedila A (2019 June 18) The Benefits of Reusable and Modular
Constructions Ennomotive httpswwwennomotivecomreusable-modular-
constructions
68) Cosentino (2020) Discover Cosentino and all the characteristics of its materials
httpswwwcosentinocom
69) Al-Hussein M Manrique J D amp Mah D (2009) North Ridge CO2 analysis report
comparison between modular and on-site construction University of Alberta Canada
70) Vickers H (2017) Modular construction 4 health and safety benefits Building 4 Education
httpsb4edcomArticlefour-health-and-safety-benefits-of-modular-construction
71) PRISM (2020) HGA and The Boldt Company build STAAT ModTM critical care units to
address the COVID-19 hospital bed shortage PRISM Modular construction 4 health and
safety benefits Building 4 Education httpsb4edcomArticlefour-health-and-safety-
benefits-of-modular-construction
72) Harrouk C (2020 September 28) Mayor of London Launches Housing Design App to
Transform Construction ArchDaily httpswwwarchdailycomauthorchristele-harrouk
73) Schoenborn J (2012) A case study approach to identifying the constraints and barriers to
design innovation for modular construction (Doctoral dissertation Virginia Tech)
74) Casas prefabricadas inHAUS (nd) servicio post-venta casa modular archivos InHAUS
httpscasasinhauscomfranceestagservicio-post-venta-casa-modular
75) Catalunya U U P (nd) MIVES mdash Departamento de Ingenieriacutea Civil y Ambiental mdash UPC
Universitat Politegravecnica de Catalunya UPC httpsdecaupceduesproyectosmives
76) Kim D (2008) Preliminary Life Cycle Analysis of Modular and Conventional Housing in
Benton Harbor MI (Doctoral dissertation)
77) Gangolells M Casals M Forcada N amp Macarulla M (2014) Analysis of the
implementation of effective waste management practices in construction projects and sites
Resources conservation and recycling 93 99-111
78) Alarcon B Aguado A Manga R amp Josa A (2010) A Value Function for Assessing
Sustainability Application to Industrial Buildings Sustainability 3(1) 35ndash50
httpsdoi103390su3010035
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
95 | P a g e
Anexo 1
a) Indicators resources
o Prefabricated Steel Modular (PSM)
Table A1 1 ndash Cost of project PSM (Hammad 2019)
Table A1 2 -Time of project PSM (Hammad 2019)
Table A1 3 - Energy utilized during construction (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
96 | P a g e
Figure A1 1 - Injury risks for workers (Hammad 2019)
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
97 | P a g e
Figure A1 3 - Co2 amount (Aye 2011)
o Prefabricated Concrete Modular (PCM)
Figure A1 4 - Total project cost (Balasbaneh 2020)
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
98 | P a g e
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter)
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020)
o Prefabricated Timber Modular (PTM)
Figure A1 8 - Co2 emission (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
99 | P a g e
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
o Traditional Reinforced Concrete (TRC)
Table A1 6 6 - Projects cost (Hammad 2019)
Table A1 7 - Projects schedule (Hammad 2019
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
100 | P a g e
Table A1 8 - Energy utilised during construction process (Hammad 2019)
Figure A1 9 - Injury risks for workers (Hammad 2019)
Figure A1 10 - Noise level (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
101 | P a g e
Figure A1 11 - Greenhouse gas emission (Aye 2011)
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
102 | P a g e
Anexo 2 1 Survey Q amp A
Q How many years of experience do your company have in modular construction
industry Table A2 1 - Professional experience of the company
Company Responses
A 10-15
B 10-15
C 20-30
D 20-30
E 30-50
Q How many years of experience do you have in the modulartraditional construction
and what is your job position Table A2 2 - Personal experience of participant
Company Responses
A 15 years
B 13 years sales manager
C 30 years of which the last 25 have been as design architect
D Quantity Surveyor
E 3 years Foreign Trade Manager
Q What types of modules your company products in terms of material Table A2 3 - Type of modules
Company Responses
A Wood Steel
B Wood
C Wood
D Wood
E Counter and Fibber cabins Steel
Q Which types of projects you did so far Table A2 4 - Type f projects
Company Responses
A Residential houses
B Schools Residential houses Commercial buildings
C Residential houses
D Schools Residential houses Hospital Commercial buildings
E Schools Residential houses hospital Commercial buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
103 | P a g e
Q Num of employees num of factories and num of modules build Table A2 5 - Characteristics of production range
Company Responses
A 80 employees 1 factory 200 modsyear
B 130 1 490
C 15
D 50 Employees 2 factories 80 build
E 250 employees 2 factories 100000 m2 prefabricated 5000 containers 1000 cabinets TURKEY
Q What was your motivation to choosework in modular construction Table A2 6 - Motivation for doing modular construction
Company Responses
A High demands in market and lack of provide Innovation
B Economic profit
C Environmental benefits High demands in market and lack of provide Innovation Shorter construction schedule due to need Economic profit
D Shorter construction schedule due to need Innovation
E Economic profit
Q Do you have sup-contracts for your panels or they had built in your factories what
is the reason for this decision Table A2 7 - Panel production conditions
Company Responses A build our own
B PE design and approvals fire suppression design and installation ceramic tile Energy Star design and inspection are all subcontracted
C All built in house in our own workshop We have developed our own unique systems which are not available elsewhere
D build in factory - programme cost
E
EPS isolated panels are produced in our factories The other are being purchased from domestic market Standard is EPS isolation and its fixed costs are lower because of quantity The others are not standard investment in production is not feasible
Q What is the level of automation technologies you use in off-site and on-site
production and assembly Table A2 8 - Level of automation
Company Responses
A Extraordinarily little today investing in this heavily this year want to get to 80
B 20
C Off-site 60 on site 20
D 20
E 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
104 | P a g e
Q Does A modular project have a smaller number of labours Less wages of salary off-
site and on-site due to specialization of workforce Does the more value added in
each hour of work can compensate Table A2 9 - Laboral status
Company Responses
A Fewer labour hours and at less cost per hour 1 hour in the factory is equal to 4 on site
B Prefabricated systems-built modular construction generally has a smaller on-site labour force for a shorter period
C Labour similar but more efficient working off site
D Yes (less no of workers and wages) - no need for special work force
E -
Q Do you have any case of recycle and reuse the structuralnon-structural elements in
your projects Table A2 10 - Recycle and Re-use
Company Responses
A Yes
B Yes
C No
D No
E Yes
Q Do you upgrade the modules with other environmentally friendly technologies such
as solar panels in your projects Please give us some examples Table A2 11 - Innovative technology integration
Company Responses
A Our homes are all self-powered only company in the world to be doing this
B
This factory allows for site installation of solar panels and other energy savings processes on site by the independent builderbuyer of our modular building materials Modular makes the most sense to be used by architects and builders with environmentally friendly tech
C
Modules (flat packed floor wall and roof components) are constructed of ply and highly insulated with non-petroleum-based insulation (recycled glass as a fibre) Solar panels fitted as an add on to completed building
D None yet not been asked
E Solar technology is YES
Q Automation in off-site production generates less or more waste of material There
are some argues about less waste generation in manual activities because of better
sense of material resistance by normal labour (wooden material for instance) Table A2 12 - Automation status on waste generation
Company Responses
A we are not automated yet but believe automation will be much more efficient use of materials
B In our experience as a custom modular manufacturer automation has a significant cost that may not be recoverable for many months if not years- millions of dollars in cost of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
105 | P a g e
components set up and training versus hourly wage and benefits of trained factory workers
C Waste is much reduced and a proportion of the waste is remanufactured to smaller items or sold on to handymen
D Would be less waste but we do not use much automation
E -
Q How much reduction does off-site modular construction has in generating ldquowasterdquo in
comparison with traditional construction methods Table A2 13 - Reduction of waste
Company Responses
A 70 less waste
B I am unable to provide an answer to this question
C
As we are timber people emissions are low regardless of construction methods Steel and concrete use are kept to a minimum and these are the high emission materials
D We are still working on our carbon footprint
E 15 less carbon emission
Q How much reduction has in ldquoenergy consumptionrdquo off-site in comparison with
conventional on-site construction What about during the operation phase Table A2 14 - Energy consumption status
Company Responses
A Our homes are not positive from an energy perspective
B
Energy consumption of a factory is known and relatively constant on a weekly monthly and annual basis The modular components for a two-box ranch style house require 3 workdays on our factory floor and 4 more days in final finish prior to shipment A competent and experienced modular builder can many times finish the entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-built house could require as much as 4 months for the same completion
C Not assessed but doubt there is much difference
D We are still working on our carbon footprint
E 30 energy saving
Q Did you deliver any projects for providing emergency services in Covid-19 period You
can mention the projects in the other section Table A2 15 - Delivery of projects in COVID-19 pandemic period
Company Responses
A No
B No
C No
D No
E Yes
Q Did you construct any projects for world aid organizations and charities You can
mention them in the other section
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
106 | P a g e
Table A2 16 - Aid organization project delivery
Company Responses
A No
B No
C No
D No
E Yes
Q Do you offer post-sale services to your clients Table A2 17 - Post-sale services to client
Company Responses
A Yes
B No
C Yes
D Yes
E Yes
Q How much was your initial costs estimate (Factory set up etc) How long was the
investmentrsquos payback period Table A2 18 - Initial costs
Company Responses
A 20 million Canadian dollar 5-year payback
B What costs Factory set up or cost of modular product sold to builders What about labour engineering transportations etchellip
C The business has been building up over decades so it is not possible to isolate specific costs
D -
E 15 million USD 5 years
Q Which factors can change the initial costs Table A2 19 - Effective factors on initial costs
Company Responses
A Level of automation Product types and production range Less sub-contracts Site location
B Design of modular building- ie roof system high wind heavy snow loads etchellip Product types and production range Site location
C Financing Level of automation Product types and production range Less sub-contracts
D Level of automation Product types and production range Site location
E Level of automation Product types and production range
Q Can component re-use building portability and the life cycle value of materials be
used as a strategy to ldquocompensaterdquo for higher initial construction costs Table A2 20 - Re-use effect on budget
Company Responses
A -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
107 | P a g e
B
We use many lumber cut-offs PVC drainpipes and conduit and dry wall pieces over many modular orders Unusable drywall shingle and PVC pieces are collected and sent out for recycling Wood is collected and recycled into mulch product or used for heating by others
C Not easily Our methods (flat pack) due not lend themselves to building portability
D -
E 50 years life span of the products
Q Which factors did you consider for choosing modular construction over traditional
method Table A2 21 - positive factors about modular construction to be chosen
Company Responses
A traditional construction is broken
B
Speed ease and cost of overall construction Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
C Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
D Transportation costs and boundaries Local salary wages
E Transportation costs and boundaries Local salary wages Environmentally friendly
Q Do use BIM in your projects what are the challenges in using BIM Table A2 22 - Use of BIM in projects
Company Responses
A 100 BIM from conceptual to finished models
B No
C No
D No
E No
Q What effects the production line can have on the design Are there any boundaries
on the architectural design Table A2 23 - Influence of production line on design
Company What effects the production line can have on the design Are there any boundaries on the architectural design
A No you just need to design with our subassemblies in mind
B This factory maximum module dimension capability is 15rsquo9
C Workshop prefabrication gives the architect far more design freedom
D Width of building for transport to make economically viable
E No
Q Is there any lack of knowledge from architects or design engineers in modular industry
about production line processes transportation limitations etc
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
108 | P a g e
Table A2 24 - Lack of knowledge among experts
Company Responses
A Yes
B No
C NA
D Yes
E Yes
Q How state transport regulation and approval can harm the projects in cost and time
Have you experience delays in your schedules because of those Table A2 25 - Transportation regulation effect on projects
Q Does the concept of transportable materials add extra costs on the project Do the
reduction of material waste and multiple discounts can ldquocompensate the lossrdquo Table A2 26 ndash Transportable material choice and its effects
Company
Does the concept of transportable materials add extra costs on the project Do the reduction of material waste and multiple discounts can ldquocompensate the lossrdquo
A Transportation costs are offset by speed of production and reduced financing costs for the project
B Not significantly
C See 26 The reverse applies
D No
E No
Q What are the difficulties in using automation in off-site production processes Table A2 27 - Challenges of using automation
Company Responses
A Codding Integration with advanced software
B Cost
C -
D Integration with advanced software
E Codding Cost Lower salaries of manual processes by labour
Company
How state transport regulation and approval can harm the projects in cost and time Have you experience delays in your schedules because of those
A Yes Some areas are slow to respond
B
Yes Some states in the US are more difficult to ship oversized and ldquosuper loadsrdquo through This adds both time and expense to the projects
C No Our company prefabricates and flat packs so all components are within or close to legal load limits
D No
E Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
109 | P a g e
Q Which problems exist in modular construction in terms of contracts What are the
solutions Table A2 28 - Contract condition in modular industry
Q What are the challenges in defining responsibilities among participants of a project
due to the changing most of the activities to precast solutions Table A2 29 - Participation status in modular projects
Company
What are the common errors than can harm the synchronization of productivity between off-site production transportation and on-site installation progress For instance less demands on-site caused
A Lack of quality partners on site that see the benefits of modular and therefore increase their pricing
B
The builder owns the responsibility to ensure that site work is done on time and correctly Delays in this can result in postponed transport of product and interest through demurrage charges
C Provided control is tight none
D -
E -
Q Considering all components are prefabricated offsite what is the role of an outside
general contractor Table A2 30 - Role of outside general constructor
Company Responses
A will always need some component of site work to complete the project
B
An outside general contractor is the independent builder The modular factory is a material vendor to the general contractor The general contractor is responsible for all site work and permits as well as storage- installation- and finish of the modular product forming the house or structure they are building
C We do not use outside general contractors All stages from earliest concept design to completed building are in house
Q How often advantageous changes must be done in the production line and what are
the challenges
Company Which problems exist in modular construction in terms of contracts What are the solutions
A Every state has a different building code need a universal code
B
In some cases the end home buyer believes the factory to be the builder and the actual independent builder to be a sales agent for the factory Our company addresses this through accuracy in the relationship described on our website and social media as well as requiring the builders customer to sign a disclosure acknowledgement from that describes the relationship in detail
C Banks do not recognise work done until it is erected on site This creates cash flow pressure where bank finance is involved
D -
E Delivery on time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
110 | P a g e
Table A2 31 - Changes in production line and its effects
Company Responses
A Slows down production
B This company incorporates changes to product materials or procedures between orders A change in process will not occur that affects only some of the components of an order
C Not sure I can answer that ion the space All means of production have advantages and challenges We have chosen methods and stick to them
Q Do you have sub-contracted players involved in your project for site preparation and
foundation phase etc why Table A2 32 - Site preparation status
Company Do you have sub-contracted players involved in your project for site preparation and foundation phase etc why
A Yes Because we are selling in many geographic areas we need local representation
B No This is the responsibility of our customer- the general contractorindependent builder
C Yes Under direct supervision Their equipment is expensive and not portable It makes sense to use local contractors for footings
D -
E Yes
Q If the onsite foundation is constructed by an outside general contractor are there
additional challenges at the interface in terms of a technology gap the equipment or
tools used the construction experience of workers or in scheduling and phasing of
construction Table A2 33 - Challenges with sub-contractors for site preparation phase
Q What are the wrong perceptions about modular products among market and public Table A2 34 - Wrong perceptions for modular products
Company What are the wrong perceptions about modular products among market and public
A that their only quality is being cheaper
B
In the USA many people the media and even professional engineers do not understand the capabilities of modular construction Many people continue to confuse this form of construction with HUD on frame products
C With our methods (flat pack) that prefabrication reduces the design options The reverse is the case
Company
If the onsite foundation is constructed by an outside general contractor are there additional challenges at the interface in terms of a technology gap the equipment or tools used the constructionhellip
A we need to educate most local subs on our process and reason for doing things a certain way
B Not that directly affects the factory
C No
D -
E -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
111 | P a g e
Q What strategies are taken among manufacturers to either improve the public
perception of modular construction or to promote its advantages to architects and
potential clients Table A2 35 - Solutions for wrong perceptions
Company
What strategies are taken among manufacturers to either improve the public perception of modular construction or to promote its advantages to architects and potential clients
A Going fast Proving the superior nature of our homes by getting more of them into the world
B
There is some cooperation between builders manufacturers architects and engineers to educate the public The national entity is the Modular Home Builders Association See httpswwwmodularhousingcom
C Nothing specific We advertise our advantages and it is enough
Q Any other challenges and recommended solutions for them that you want to add
please Table A2 36 - Recommendations
Company Responses
A -
B -
C The capital cost of equipment Specialised digital equipment is expensive making it difficult for small and medium companies to enter the market
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Abstract
During past century construction industry is suffering from a poor productivity rate in
comparison with the other industries To solve this problem the concept of industrialization in
construction was introduced which Modular construction is one of its methods with a not short
history However during past decade had changed its nature to be used for longer lifetime as
permanent uses
The purpose of this study is to identify the possible advantages and investigate on common
challenges related to modular construction industry in a project management perspective and intend
to find adequate solution for them The methodology of this study is a combination of quantitative
and qualitative based approaches
A multi-criterion decision-making software (MIVES) was used to measure the functionality of
advantages and their effect on final decision to use ether three modular alternatives (Steel timber
and concrete) or a traditional reinforced concrete method for building a residential project The results
showed that despite few poor performances in two environmental criteria (CO2 emission amount and
Embodied energy used during construction) in general all three modular alternatives had overcome
traditional option in every requirement where prefabricated timber modular method became the
most sustainable alternative This result can confirm the positive effect of modular construction
advantages and show its superior nature over conventional construction
In addition a qualitative online survey form was sent to modular players to confirm the
identified benefits discussion about common challenges and receive recommendations and solutions
to solve them The responds were collected from five companies with the average of 20 years of
experience in modular construction which illustrated that the advantages can be achieved in real
projects as well as the literature review and study cases on decision making process identified
On the other hand there are challenges remaining without resolution such as Lack of
partnership among participants of project conflicts by local codding in use of automation wrong
perceptions of market etc
The possible solutions could be creating an international code for modular products
advertisement on potential advantages of modular method in publicmarket updating the contract
condition and most important of all improving the cooperation between scientific investigators and
off-site industry to motivate and provide the researchers with more real data to prevent contrasts in
hypothesises and find more innovative solutions1
Keywords Sustainability Modular construction Embodied energy Prefabrication Lifecycle assessment (LCA) Building information modelling (BIM) MIVES Productivity rate Standardization
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table of Contents Table of Contents 2
1 Introduction 1
Motivations 1
Orientation of previous studies 1
Gap of knowledge 1
Objectives of the study 2
Survey among the professionals in the modular industry by Online Form 2
Decision-making among three modular methods and conventional option by MIVES 2
Limitations 2
Lack of existence of references related to the subject 2
Non-accessible information from companies and scientific articles 2
Obstacles caused by global lockdown during covid-19 pandemic 2
Organization of the thesis 3
2 State of the art 4
Productivity problem in construction industry 4
Status of productivity rate of construction industry among other industries 4
Reasons of poor productivity 6
Solutions for improvement 7
Brief on modular construction 10
History of modular construction 10
Types of modular product 15
Module architectural types 15
Module structure types 22
Types of modular buildings based on operation period 27
Common uses of modular buildings in the market 27
Construction phases 28
Literature review on possible advantages 31
Scheduling benefits 31
Economic benefits 34
Environmental Benefits 36
Health and security benefits 38
Social-Laboral benefits 39
Modular Construction role in COIVD-19 Pandemic 40
Review on common challenges 41
Initial costs 41
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Architectural challenges 43
Transportation challenges 44
Wrong perceptions among public and real estate market 45
Integration of advanced software 46
Redefining the contracts 46
Supply chain-transportation-onsite assembly management errors 47
3 Common challenges in modular construction industry by a survey 48
Methodology 48
Objective 48
Role of the researcher 48
Ethical considerations 48
Survey setting 48
Development of questionnaire 49
Participant profile 50
Experience amp professions 50
Data collection 51
General information 51
Economic issues 52
Environmental status 52
Social Benefits 53
Initial costs 54
Design limitations 55
Transportation Limitations 55
Project management challenges 56
Social challenges 57
Data analysis amp conclusions 57
Advantages 57
Challenges discussion 58
4 Decision making based on potential advantages among three modular alternatives and
conventional construction method in a project by MIVES software 60
Methodology 60
Objective 60
What is MIVES 60
Data collection process 60
Case Study references 60
Input data 65
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Final indicators 69
Weights 73
Data analysis 76
Indicators Values 76
Criteria Values 77
Requirement Values 81
Sustainability Values (Final decision) 83
5 Conclusions 84
Decision making process 84
Conclusions and discussion 84
ECONOMIC ndash TIME discussion 84
ENVIRONMENTAL discussion 84
SAFETY AND SOCIAL dominance by modular methods 85
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES 85
Effective external factors on decision 86
Future studies 86
Decision making study on two real projects with the input data of professional
modular and traditional constructors 86
Technological studies about the production line of a modular off-site plant by factory
and on-site visits 86
A survey about challenges in modular construction and its possible solutions to find
adequate solutions 86
Recommendations 87
Cooperation between industrial players and scientific researchers in offsite
construction 87
Education about industrialization in construction and its alternatives 87
Establishing international and regional adequate codes 87
Synchronizing the contract conditions with modular construction conditions 87
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc 88
Changes in financial strategies and adapting them with off-site construction nature 88
6 References 89
Anexo 1 95
Anexo 2 102
1 Survey Q amp A 102
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study 4
Figure 2 2 - UK productivity status (Office for National Statistics -ONS) 5
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS) 5
Figure 2 4 - Value added comparison among industries (ennovacom) 6
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom) 6
Figure 2 6 - Fragmentations between construction industry players and their various productivity
rates (McKinsey 2019) 7
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom) 8
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom) 9
Figure 2 9 - Digital construction organization (wwwbimcommunitycom) 9
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom) 10
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom) 11
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom) 11
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8
meters (modulartch) 12
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau) 13
Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
14
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom) 15
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom) 16
Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom) 17
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom) 17
Figure 2 20 - Production steps of floor cassette to walls and their attachment together
(wwwhowickltdcom) 18
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom) 19
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom) 19
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom) 20
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom) 20
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom) 21
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-
Malec (wmengcom) 21
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo) 22
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
23
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported
module (wwwsteelconstructioninfo) 24
Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the
lower levels (wwwsteelconstructioninfo) 25
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other
metals (vanguardmodularcom) 26
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma
Beton) 26
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction
report MBI 2019) 28
Figure 2 34 - Overlaps of phases in modular construction project 29
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom) 30
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method
(McKinsey amp Company 2019) 31
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom) 33
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom) 33
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes) 34
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom) 34
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk) 35
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images) 36
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site
(wwwcadoltocom) 37
Figure 2 44 - various layers of a module building unit including insulations
(wwwsteelconstructioninfo) 38
Figure 2 45 - Compartment floor at junction with external wall and compartment wall
(wwwsteelconstructioninfo) 39
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use
inside convention centres arenas and temporary structures Image courtesy of HGA and The Boldt
Company (prismpubcom) 40
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The
Boldt Company 40
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction
(archdailycom) 41
Figure 2 49 -Balance between Initial costs and Economical benefits 42
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects
(casasinhauscom) 46
Figure 2 51 - synchronization between supply chain transportation and on-site assembly 47
Figure 3 1 - Online office forms for survey use 49
Figure 3 2 - Questionnaire development 50
Figure 3 3 - Participants motivations to start a modular company 51
Figure 3 4 - Re-use potential 53
Figure 3 5 - Contribution in Covid19 epidemic 53
Figure 3 6 - Post sale services por future clients 54
Figure 3 7 - effective factors in initial investments for start-up companies 54
Figure 3 8 - Lack of knowledge among designers and engineers 55
Figure 3 9 - challenges of using automation in off-site plants 56
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study
(WAHammad 2019) 61
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and
conventional methods (Akbarnezhad 2019) 61
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020) 62
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017) 62
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad
2017) 63
Figure 4 6 - Architectural section of multi-residential building (Aye 2011) 63
Figure 4 7 - Structural elements used in modules (Aye 2011) 64
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012) 64
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES) 65
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM
alternatives 71
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software 74
Figure 4 12 - Possible forms of the value function 75
Figure 4 13 - Value function for total project cost in MIVES 75
Figure 4 14 - Criteria normalized values 77
Figure 4 15 - Project Schedule 78
Figure 4 16 - Waste generation ratios 78
Figure 4 17 - CO2 Emission normalized values 79
Figure 4 18 - Recyclability and re-use potential of alternatives 79
Figure 4 19 - Embodied energy consumption and saving potential by reuse 80
Figure 4 20 - Safety advantage of modular construction over traditional method 80
Figure 4 21 - Social criteria 81
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values
analysed by MIVES 81
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind 82
Figure 4 24 - Modular dominance in safety and social requirements over conventional option 82
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives 83
Figure A1 1 - Injury risks for workers (Hammad 2019) 96
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
96
Figure A1 3 - Co2 amount (Aye 2011) 97
Figure A1 4 - Total project cost (Balasbaneh 2020) 97
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
97
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter) 98
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020) 98
Figure A1 8 - Co2 emission (Aye 2011) 98
Figure A1 9 - Injury risks for workers (Hammad 2019) 100
Figure A1 10 - Noise level (Hammad 2019) 100
Figure A1 11 - Greenhouse gas emission (Aye 2011) 101
Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo) 23
Table 2 2 - Possible benefits in projects scheduling 32
Table 2 3 - Economic benefits in modular method 35
Table 2 4 - Environmental Benefits 37
Table 2 5 - Health and safety amp Social-Laboral advantages 39
Table 3 1 - Participantrsquos profiles 50
Table 4 1 - Requirement tree with all indicators which considered for decision making process 67
Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed
to be done on them 68
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other
studied 68
Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow) 68
Table 4 5 - Qualitative indicators 69
Table 4 6 - First hand data over literature 69
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow) 70
Table 4 8 - First hand data over literature 70
Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue) 70
Table 4 10 - First hand data over literature 70
Table 4 11 - Final indicators for PCM 72
Table 4 12 - TRC first-hand data over literatures 72
Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow) 72
Table 4 14 - Final Quantitative indicators used for decision making process 72
Table 4 15 - Requirement weights 73
Table 4 16 - Weights of criteria 73
Table 4 17 - Value function for indicators in MIVES 76
Table 4 18 - Indicators normalized values 76
Table 4 19 ndash Indicator normalized values 76
Table 4 20 - Criteria normalized values 77
Table 4 21 - Criteria normalized values 77
Table 4 22 - Requirement normalized values for four indicators 81
Table 4 23 - SI (Sustainability Indexes related to four alternatives) 83
Table A1 1 ndash Cost of project PSM (Hammad 2019) 95
Table A1 2 -Time of project PSM (Hammad 2019) 95
Table A1 3 - Energy utilized during construction (Hammad 2019) 95
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 96
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 99
Table A1 6 6 - Projects cost (Hammad 2019) 99
Table A1 7 - Projects schedule (Hammad 2019 99
Table A1 8 - Energy utilised during construction process (Hammad 2019) 100
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011) 101
Table A2 1 - Professional experience of the company 102
Table A2 2 - Personal experience of participant 102
Table A2 3 - Type of modules 102
Table A2 4 - Type f projects 102
Table A2 5 - Characteristics of production range 103
Table A2 6 - Motivation for doing modular construction 103
Table A2 7 - Panel production conditions 103
Table A2 8 - Level of automation 103
Table A2 9 - Laboral status 104
Table A2 10 - Recycle and Re-use 104
Table A2 11 - Innovative technology integration 104
Table A2 12 - Automation status on waste generation 104
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table A2 13 - Reduction of waste 105
Table A2 14 - Energy consumption status 105
Table A2 15 - Delivery of projects in COVID-19 pandemic period 105
Table A2 16 - Aid organization project delivery 106
Table A2 17 - Post-sale services to client 106
Table A2 18 - Initial costs 106
Table A2 19 - Effective factors on initial costs 106
Table A2 20 - Re-use effect on budget 106
Table A2 21 - positive factors about modular construction to be chosen 107
Table A2 22 - Use of BIM in projects 107
Table A2 23 - Influence of production line on design 107
Table A2 24 - Lack of knowledge among experts 108
Table A2 25 - Transportation regulation effect on projects 108
Table A2 26 ndash Transportable material choice and its effects 108
Table A2 27 - Challenges of using automation 108
Table A2 28 - Contract condition in modular industry 109
Table A2 29 - Participation status in modular projects 109
Table A2 30 - Role of outside general constructor 109
Table A2 31 - Changes in production line and its effects 110
Table A2 32 - Site preparation status 110
Table A2 33 - Challenges with sub-contractors for site preparation phase 110
Table A2 34 - Wrong perceptions for modular products 110
Table A2 35 - Solutions for wrong perceptions 111
Table A2 36 - Recommendations 111
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
1 | P a g e
1 Introduction
Motivations
Construction industry is suffering for a poor productivity problem during the past 60 years in
comparison with other industries and industrialization in construction was suggested by the
investigators to improving the construction performance by applying production technologies and
design standardized products to be built in off-site plants By searching over the off-site methods
modular construction was found which is benefiting its high sustainability and productivity in
comparison with traditional construction approaches
One of the motivations of these study is to study the advantages of modular construction in
order to demonstrate the superior nature of modular construction over traditional methods to be
presented as a reasonable solution for productivity problem the However there are various of
opinions and argues about the beneficiary of this method so that it was decided to analyse them more
deeply in construction management perspective and even get into contact with the industry for
professional confirmation
Another motivation of this study was to contribute to development of modular construction
and find what is holding it back from developing by discovering the challenges in the modular
construction industry and find possible solutions to help for growth
Orientation of previous studies
During past two decades fewer studies in comparison with other innovative methods have
focused on this subject to analyse this method in economic environmental and functional areas to
discover the benefits and make comparisons with traditional construction methods where possible
McKinsey amp company report on 2019 had general overview on its potential advantages challenges
and its ability to raise the productivity in construction processes while introducing the benefits by
making comparisons in projectrsquos schedule budget and environmental performance among modular
and traditional methods and finally shedding a light on dark side which are the obstacles of growth in
industry and then suggesting possible solutions for improvements In addition there are numbers of
articles focusing on the environmental performance of modular buildings by doing Lifecycle
assessment (LCA) analysis on emissions waste generations and consumption primary resources etc
(Mohammad Kamali and Kasun Hewage et al 2016)
On the other side there are studies that made comparisons between traditional and modular
methods of construction to build a specific project based on BIM models and professional data bases
which led to great results that showed numbers of advantages (AWA Hammad et al 2019) (L Aye
et al 2011) (Ali Tighnavard Balasbaneh at Springer-Verlag 2020)
Gap of knowledge
Taking into account of existent researches there is a gap of knowledge which leads to few
questions that still have remained without answer
bull Confirmation of these benefits that came from scientific researches by professional
players in the industry
bull Do these advantages effect the final decision to choose modular method over
conventional way
bull What are the needs of the market that could be as motivations to use modular
construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
2 | P a g e
bull What are the challenges in the industry in the professional point of view
bull Do the solutions that suggested by researchers can be applied in real projects What
are their professional solutions
Objectives of the study
The importance of this study is to resolve the mentioned questions by accomplishing the
studyrsquos objectives that are separated to be achieved by two methods which are qualitative and
quantitative
Survey among the professionals in the modular industry by Online Form
bull To confirmcorrect the data from literature reviews about benefits of modular
construction
bull Their motivations and reasons to choose modular method
bull What are the constraints and obstacles that they are facing
bull Recommendations and solutions for these problems
Decision-making among three modular methods and conventional option by MIVES
bull To discover the advantages in real study cases by comparisons between four
alternatives
bull To examinate the functionality of every alternative in several criterions
bull How much effective these benefits can be in the final decision based on the
requirements of market and their priorities
Limitations
Several obstacles were seen during the study that effected the methodology and input data
significantly Here are some examples
Lack of existence of references related to the subject
Because of the subjectrsquos novelty or less focus the quantity of references is not enough to
cover all the dimensions of study therefore few estimation hypothesis (that were proved by the
results at the end) and consultants with experts were used instead to provide the necessary
information In addition many of the scientific reports and articles were published few months or
even days before the studyrsquos conclusions so that it was decided to be used immediately to improve
the studyrsquos liability
Non-accessible information from companies and scientific articles
There are innovative companies that because of their privacy policies and protection of
innovation could not provide the necessary data about their projects by request even for academic
uses
On the other side scientific papers in some cases were protected and did not have open
access not even with educational access permissions as requests have been denied by the authors
Obstacles caused by global lockdown during covid-19 pandemic
One of the unpredicted challenges that happened during the study was the virus pandemic
that affected the world negatively and this study was not an exception From on-site project and off-
site factory visits interviews with experts in the industry etc were cancelled Numbers of regions went
to full shutdown including offices factories etc which resulted in reduction of participations in online
survey form as well Therefore it was decided to select five most suitable participants to be analysed
instead of planed massive quantity of results
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
3 | P a g e
Organization of the thesis
⎯ Chapter two state of the art explaining the productivity problem history types and
phases of modular construction and literature reviews on benefits and challenges
⎯ Chapter three The online survey among modular players in the industry
⎯ Chapter four MIVES multi-criteria decision-making approach
⎯ Chapter five Conclusions and findings
⎯ Chapter six Recommendations
⎯ Chapter seven references
⎯ Anexo A (Input data references)
⎯ Anexo B (Survey QampA) 2
Kewwords Sustainability Modular construction MIVES Productivity rate Prefabrication Lifecycle assessment (LCA)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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2 State of the art Productivity problem in construction industry
Status of productivity rate of construction industry among other industries
It has been decades that construction industry is far behind the other industries in terms of
productivity rates Attempts had been done by innovative players in the industry but still the
difference is too enormous which the demands for improvement are needed
Globally construction sector labour-productivity growth averaged 1 percent a year over the
past two decades compared with 28 percent for the total world economy and 36 percent for
manufacturing If construction productivity were to catch up with the total economy the industryrsquos
value added could rise by $16 trillion a year (McKinsey 2019)
It can be said that the building industry is one of the key industries in the general economy
The construction sector typically comprises 8-10 of the Gross Domestic Profit (GDP) of a Western
economy (McGeorge amp Palmer 2002) Therefore only 10 improvement in construction
performance can represent a 25 increase in GDP (McGeorge amp Palmer 2002) Therefore there is
no doubt that improving productivity in the building industry will contribute positively to the general
economy
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
5 | P a g e
The UK has a problem with productivity and the construction sector has poorer productivity
growth rates than any other Simply put productivity is the amount of stuff (whether goods or
services) that is produced by a person in an amount of time UK productivity is lower than it was in
2008 and the construction industry has not seen any significant growth in productivity in the last 20
years (Figure 22)
Figure 2 2 - UK productivity status (Office for National Statistics -ONS)
Not all the regions are struggling at the same rate and the reasons which will be discused
furthermore can be the insterest of regulators to support innovations and new solutions which can
improve the productivity in construction industry(Figure 23)
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS)
The result is that between 70 and 90 of projects exceed the original planned cost and that
the overrun commonly varies between 50 and 100 of budget Construction also suffers from 57
of effort on non-value-added activities compared with 26 within manufacturing (Figure 24)
These productivity rates had experienced severalrises and downs in some periods which is
because of increase of demandas of housing that results a boost in construction industry in order to
provide the needs
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Figure 2 4 - Value added comparison among industries (ennovacom)
Reasons of poor productivity
There are numbers of reasons for this poor performance The industry is extensively
regulated very dependent on public-sector demand and highly cyclical Informality and sometimes
corruption distort the market Moreover poor project management and execution insufficient skills
inadequate design processes and underinvestment in skills development RampD and innovation can
affect the productivity indirectly by decreasing the feasibility and value of the activities and add extra
costs on the project
Another key factor that causes a disruption among construction players which reduces the
average productivity rate is the lack of harmony in productivity between the players In other words
The sector divides mainly in two large-scale players involved in heavy construction such as civil and
industrial work and large-scale housing and a large number of firms engaged in fragmented
specialized trades such as mechanical electrical and plumbing work that act as subcontractors or
work on smaller projects like refurbishing single-family housing The first group manages to have 20
to 40 percent higher productivity than the second However even in the more productive heavy
construction sector there are endemic-potentially structural-challenges in meeting cost and schedule
commitments on megaprojects and players routinely subcontract specialized trades (McKinsey amp
Company 2019) (Figure 26)
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
7 | P a g e
Figure 2 6 - Fragmentations between construction industry players and their various productivity rates (McKinsey 2019)
Solutions for improvement
Nowadays there are solutions which are being used in construction world such reshaping the
regulation rewiring the contractual framework to reshape industry dynamics rethink design and
engineering processes improve procurement and supply-chain management improve on-site
execution infuse digital technology new materials and advanced automation and reskill the
workforce Each region based on their capabilities potential and Infrastructures would take a decision
which ways can be applied to increase the productivity in construction projects in a short or long
period
bull Redefine regulation Actions include streamlining permitting and approvals processes as
Australia has done reducing informality and corruption and encouraging transparency on cost
and performance as the International Construction Measurement Standards project does Many
governments allocate grants for innovation and training Germanyrsquos Federal Ministry of Transport
and Digital Infrastructure (formerly the Federal Ministry of Transport Building and Urban
Development) for instance supports RampD through studies in building materials Best practice
regulation would include moving toward outcome-based more standardized building codes and
consolidating land to promote scale Examples include Singaporersquos move to allow cross-laminated
timber (CLT) for high-rise structures and Japanrsquos promotion of scale through land pooling
bull Re-arrange the contractual framework Establishing a ldquosingle source of truthrdquo on projects for
monitoring progress early potentially supported by collaborative technology helps to minimize
misalignments and enable joint corrective action The data already exist to fundamentally
improve the accuracy of cost and schedule estimates Where players continue to use traditional
contracts they should introduce incentives that significantly improve performance and alignment
not at a trade or package level but at the project-outcome level To move toward best practices
appropriate alternative contracting models such as integrated project delivery (IPD) help build
long-term collaborative relationships Relational contracts will need to become more prevalent
than transactional contracts Sufficient investments in up-front planning incorporating all partiesrsquo
input have been shown to raise productivity substantially Smart Contracts are another example
of these solutions which during recent years is being identified by the major players A smart
contract is a computer program or a transaction protocol respectively which is intended to
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
8 | P a g e
automatically execute control or document respectively legally relevant events and actions
according to the terms of a contract of an agreement or of a negotiation The objectives of smart
contracts are the reduction of need in trusted intermediators arbitrations and enforcement costs
fraud losses as well as the reduction of malicious and accidental exceptions (Tapscott Don
Tapscott Alex amp Savelyev Alexander 2016)
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom)
bull Off-site production shift The biggest impact on productivity would come from moving toward
thinking about construction as a production system where possible encouraging off-site
manufacture minimizing on-site construction through the extensive use of pre-cast
technology assembling panels in factories and then finishing units onsite
bull Improve on-site execution There are four key approaches that are well known in the industry
but have not been universally adopted First is the introduction of a rigorous planning process
the Last Plannerreg System (LPS) is a useful tool to ensure that key activities are achieved on
time and on budget The use of integrated planning tools on a large-scale oil and gas project
for instance achieved a 70 percent increase in the projectrsquos productivity Second is reshaping
the relationship and interactions between owners and contractors and key performance
indicators (KPIs) being agreed on and used at regular performance meetings at which on-site
issues are resolved Complementing commonly used KPIs with additional forward-looking plan
conformance metrics to identify and subsequently reduce variance is critical Third is
improving the mobilization for new projects by ensuring that all pre-work (for instance
obtaining approvals and developing project milestones) has been completed prior to starting
onsite Finally there is a need for careful planning and coordination of different disciplines
on-site along with the application of lean principles to reduce waste and variability On-site
productivity can be increased by as much as 50 percent by implementing a cloud-based
control tower that rapidly assembles accurate data in near real time that is both backward-
looking and predictive (for example using plan conformance and other variability and
inventory metrics)
bull Introduce digital technology advanced automation Companies can start by making 3D
building information modelling (BIM) universal within the company alongside use of digital
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
9 | P a g e
collaboration tools drones and unmanned aerial vehicles for scanning monitoring and
mapping They can put themselves at the cutting edge by using platforms such as 5D BIM to
establish transparency in design costing and progress visualization (Figure 28)
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom)
Advanced analytics enabled by the Internet of Things to improve on-site monitoring of
materials labour and equipment productivity and digital collaboration and mobility tools (such as
construction management apps loaded on mobile devices) to better track progress and collaborate in
real time (Figure 29)
Figure 2 9 - Digital construction organization (wwwbimcommunitycom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Advanced automated equipment and tools such as bricklaying and tiling robots can accelerate
on-site execution The field of digital fabrication (dfab) is quite broad and has many applications Dfab
techniques are based on the combination of computational design methods and automated
construction processes which are typically categorized as subtractive formative or additive
(Kolarevic 2003) The use of subtractive and formative digital fabrication is becoming mainstream in
the prefabrication (off-site) of building parts (eg by using laser cutting CNC milling etc)
In recent years additive fabrication processes especially 3D printing have experienced a
rapid development in many industries As interest in additive fabrication grows research into large-
scale processes begins to reveal potential applications in construction (Labonnote et al 2016)
Existing additive dfab technologies can be classified in two big clusters on-site and off-site
construction technologies On the one hand on-site digital fabrication aims to bring additive
fabrication processes on construction sites
Sousa et al (2016) classified on-site technologies in three main categories large scale robotic
structures mobile robotic arms and flying robotic vehicles A well-known example from first category
is Contour Crafting a robotic structure for 3D printing large-scale construction developed at the
University of Southern California (Khoshnevis 2004)
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom)
bull Reskill the workforce Change in the construction sector cannot be achieved without
investment in retooling a workforce that is aging and changing its makeup through migration
Construction firms and workers need to continuously reskill and train to use the latest
equipment and digital tools In the mix should be apprenticeship programs such as the one
run by Siemens in the United Kingdom training frontline workers in core skills that are
currently underdeveloped and increasing stability in the workforce by breaking seasonality
and cyclicality
Brief on modular construction
History of modular construction
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11 | P a g e
bull 1800s
In 1830 he first documented prefabricated home was created by London carpenter John
Manning for his son who was moving from England to Australia Manning built a prefabricated house
in pieces then shipped it to the Land Down Under for easy assembly In 1840 Modular construction
made its way to the United States in response to the housing needs of the California Gold Rush The
Crystal Palace was built for Britains Great Exhibition and remains one of the most famous examples
of early modular construction in 1851 Designed in less than two weeks it utilized light and
inexpensive materials such as iron wood and glass it was constructed in only a few months
Afterward the palace was dismantled moved and rebuilt at another location
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom)
bull 1900s
Augustine Taylor a builder in Chicago devised the balloon-frame method (Figure 212)
enabling walls to be built offsite then transported to the intended construction site for speedy
assembly The rise of catalogue houses happened Between 1908 and 1940 when Sears Roebuck and
Co sold more than 500000 prefab homes through its catalogue straight to consumers At the time
these houses cost less than two-thirds of conventionally built homes and many still exist throughout
the United States
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull WWII Housing Boom
Prefab structures continued into World War Two to meet the growing demand for mass
accommodations for military personnel So-called Quonset Huts or Nissen Huts in the UK
comprised of corrugated steel were introduced for domestic military and institutional uses
When soldiers began returning home in the United States there was a need for rapid
construction for new homes to accommodate these expanding families Once again modular
construction serviced those needs because of its efficiency reduced costs and quick construction
Today many of those units are still in use
bull Prefab in Post-war Europe
The situation in Europe was more difficult although millions of people had no place to live on
the Old Continent due to the destruction of the Second World War people were unwilling to accept
prefabricated construction In Germany which had not only lost 25 percent of its entire housing stock
to bombing but also had to integrate 12 million refugees from former German territories in Eastern
Europe one form of prefabricated housing was used extensively the Nissen Hut (similar to the
Quonset hut) An attempt was also made in post-war France to combat housing shortages with the
help of prefabricated houses In 1944 Jean Prouveacute was already commissioned by the Ministry of
Reconstruction and Urban Planning to build 800 houses as emergency shelters that could be easily
disassembled However only 400 of these Maisons agraveportique which were equipped with an axial
steel frame were ever erected Prouveacutes Alba houses developed for the Abbey Pierres homeless
organization in 1956 were also not a success (Peter Goumlssel Arnt Cobbers Oliver Jahn 2012
architectureweekcom)
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8 meters (modulartch)
bull The Pre-fabulous 60s
The 1960s were a period of social transition in which attitudes towards prefabricated housing
also changed During this era which was marked by space travel the moon landing and even childrens
books that predicted weekend trips to distant galaxies prefabricated construction was discovered both
as a form of artistic expression and as a technical means of creating houses to provide a basis for new
lifestyles which seemed to be imminent in a society characterized by an extremely optimistic view of
progress
These approaches supported the idea of creating megastructures out of residential capsules
the architect Moshe Safdie who was only 24 at the time presented his megastructure Habitat 67 at
the Expo 67 in Montreal 158 housing units consisting of 354 concrete modules assembled as a
conglomerate
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The British architectural group Archigram developed building structures made of residential
capsules as an architectural Utopia which could be expanded at will and joined to form entire cities
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau)
bull Eco-conscious 70s
In 1972 the Japanese architect Kisho Kurokawa built the Nakagin Capsule Tower in Tokyo
housing cells were layered around a prefabricated concrete core to form a fourteen-story residential
tower(Figure 215) The idea of residential capsule megastructures was repeatedly revived as in Zvi
Heckers Ramot housing development in Jerusalem in 1974
The ecology movement of the 1970s brought an end to this euphoria regarding technological
progress and futuristic architectural dreams Now highly modern building materials that did not seem
to be in harmony with a return to nature such as plastic or aluminium fell into disrepute A new
perspective of view replaced as a priority to choose the material types which have the minimum
relation with non-renewable resources
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
bull 90s
This was further exacerbated by the fact that prefabricated elements had often been used to
build high-density housing which was now generally viewed negatively Hence prefabricated building
now came to be associated with the aesthetic and social failure of deindividualized megalomaniac
prefabricated slab housing blocks clustered on the periphery of large cities Thus the acceptance of
the prefabricated house in large parts of Europe remained low up until the 1990s
Prefabricated construction only gradually began to again emancipate itself from a homespun
cheap mass-produced image during the 1990s This is mainly due to the use of computer-operated
programs in the design and production processes The prefabricated housing industry now stands at
a juncture reminiscent of the dynamism of the 1920s and 1930s
bull Modern days
For many years now companies like Muji in Japan or BoKlok in Scandinavia and more recently
also in Poland and England have been supplying prefabricated houses in large numbers In Sweden
alone with only nine million inhabitants 14000 units are sold every year Muji offers models designed
by Kengo Kuma and Kazuhiko Namba that are as simple as they are elegant and far more interesting
than the building-kit houses offered by the multinational concerns Mitsubishi Toyota and Panasonic
(deluxemodularcom 2019)
Countries around the world have enlisted prefab and modular construction methods for
decades For example an estimate of all detached homes that are prefabricated in each country
shows a potential for growth off 84 in Sweden 5 in the United States 9 in Germany 20 in the
Netherlands and 28 in Japan
Today prefabrication and modularization are utilized in the construction of hotels apartment
buildings offices hospitals and schools in every major US city Here is a rundown of the percentage
per industry of prefabricated structures that use some form of modular construction
(deluxemodularcom 2019)
bull 49 of healthcare facilities
bull 42 of college buildings and dorms
bull And 42 of manufacturing buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Types of modular product
Module architectural types
The products can be categorized by its functions dimensions material or type of its operation
etc Here they will be introduced by their general characteristics
bull Bathroom pods
Bathroom pods are commonly used in the construction of most hotels and apartment
buildings these days and becoming used more for residential housing The main drivers for choosing
a modular pod method are
o The cost savings that can be made by building repeated designs in a factory
environment
o Higher quality finish
o Rapid installation
o No trades on site
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom)
Pod Construction Process can be various but the most common steps can be as below
(httpswwwhowickltdcom)
Once the bathroom specification has been finalized and the design completed the
machine files are issued and the framing can be produced
The frames are rolled out of the machine ready for assembly
The panels are assembled
The panels are then fitted with the internal boarding and finished with tiles or a
waterproof lining
The walls floor and roof are joined to create the room structure and the joints sealed
The fixtures and fittings can then be installed including
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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o Bath or shower
o Toilets
o Basins
o Lights
o Mirrors
o Cabinets
The plumbing and electrical components are connected
The pods are then subjected to an electrical test and a pressure test to ensure there
are no leaks (Figure 217)
The pods are then sealed to prevent access ready for transportation
Once on site the pods are slid into position and connected to the power and water services
This process greatly reduces the build time as there are no requirements for trades on the site As the
pods are sealed until the building is completed there are reduced chances of them being damaged
during the building construction phase
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom)
bull Kitchen pods
These pods are less common but are also becoming more frequently used All the appliances
and electrics can be fitted in the factory removing the need for work on site Kitchen pods are ideal
for renovating older or industrial buildings as all the electrical services for the building can be
integrated into the pod From student accommodation to residential flats modular kitchen pods are
suitable for a variety of different sectors and uses and because they are designed bespoke to each
clientrsquos exact specifications they can be anything from a fully fitted kitchen to a small kitchenette
Each modular unit is completely customisable from the worktops to the splashbacks and integrated
white goods
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Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom)
bull Volumetric and modular rooms
Volumetric and modular rooms are becoming widely used for buildings that have a repetitive
nature Common structures include
bull Hotels
bull Apartments
bull Student accommodation
bull Schools
bull Hospitals
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The benefits of being able to manufacture the complete unit in the factory (including the
bathrooms and fitting of furniture) are
o No weather delays
o Superior finish quality
o All the electrical and plumbing works are done in a controlled atmosphere
o The rooms are sealed before moving to site restricting unauthorized access
Modular rooms production process can be explained as below
Once the building design has been completed and the individual modules specified the
framing components can be made on a just in time basis for site delivery
A typical assembly process would consist of
The floor cassette is rolled and the flooring boards are attached along with the
required insulation and services
The wall and ceiling frames are assembled
The internal lining is fitted and painted
The wall frames are then attached to the floor cassette (Figure 220)
Figure 2 20 - Production steps of floor cassette to walls and their attachment together (wwwhowickltdcom)
The ceiling frames are then fitted
The bathroom can then be fitted and plumbed as well as the electrical fittings and
wiring
The wall and ceiling insulation is added to the frame
The fit-out can then be completed to the desired specification
A hotel module for example would feature carpets bed bedside furniture desk
wardrobe TV system air-conditioning (either vents from main system or stand-alone
unit) bathroom fittings and fixtures
Once completed the electrics are checked and the plumbing is pressure tested
A protective cover is then added for transport and the unit is delivered to site
On-site the units are craned into position and joined
The services are connected
The building is then roofed and clad to the required specification In some cases the cladding
can be fitted during the module assembly further reducing the on-site work
bull Modular Trailers
Outside of modular homes modular trailers are probably the type of modular building that
people are most familiar with These buildings have a lot of applications and are often used as a
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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temporary space solution These trailers can be relocated for several times and are well-equipped as
well Temporary pre-semester school classes and temporary offices can be two examples of these
trailers uses
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom)
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom)
bull Containers
When looking at modular containers they are structures that are typically used to contain a
shiprsquos cargo When Shipping containers were originally created they were designed with modularity
in mind They were required to withstand all kinds of abuse as they journey through some of the
worldrsquos harshest climates From salt water to freezing temperatures a shipping container is meant to
handle the worst of the worst while protecting some of the worldrsquos most precious cargo Comprised
of Corten steel it is in a shipping containers DNA to protect itself from any corrosion or rust and when
they fall off the ship they can take up to a week to sink With more boxes being imported than
exported we have an opportunity to reuse something that is desperately looking for a new home
There has been a shift recently where after these buildings serve their purpose as shipping containers
they are reused fitted with windows doors HVAC units etc And made into an office environment
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The biggest benefit of these containers is they are cheap very portable and easy to install on site
However since most of the time these buildings are retrofitted and remodelled into modular
buildings they usually do not have a lot of flexibility in layout or their dimensions
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom)
Shipping containers act as the exoskeleton of each module The original structure will frame
the HVAC wiring lighting plumbing appliances and wall finish materials Because containers were
built to be durable and mobile they can be transported by train tractor-trailer boat or in some cases
a powerful pickup truck Forklift pockets and corner castings allow the containers to be moved smaller
distances by crane and forklift Shipping containers empower you to move your modular structures
without sacrificing the structural integrity or damaging the modulersquos contents
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull Office Complexes
Office complexes will take several office modules and combine them to assemble a much
larger fully functioning office building Just like all modular construction these modules are
fabricated in a manufacturing environment except when these projects reach the job site they
function more similarly to a full-fledged construction site Generally the module will need a crane to
lift the section from the ground and place it in the correct spot to assemble the building Next the
workers will go through that module and do all things necessary to attach and hook up the piece
Then the next piece is put in place and these steps are repeated and again until the building is
finished
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom)
bull Modular enclosures
For instance one of the major electric utilities in the Northeast using Modular Construction is
Wunderlich Malec Integrated Control Enclosures since 2001 A standard 16times50times11-foot enclosure
with twenty (20) protective relay and control cabinets marshalling cabinets HVAC fire and security
completely installed wired and tested at the factory prior to shipment
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-Malec (wmengcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Module structure types
Modular structure types can be categorized by their materials or structural formation
o Steel Modules
bull 4-sided modules
In this form of construction modules are manufactured with four closed sides to create
cellular type spaces designed to transfer the combined vertical load of the modules above and in-
plane loads (due to wind action) through their longitudinal walls The cellular space provided is limited
by the transportation and installation requirements Depending on location and exposure to wind
action the height of buildings in fully modular construction is in the range of 6 to 10 storeys Modules
are manufactured from a series of 2D panels beginning with the floor cassette to which the four wall
panels and ceiling panel are attached generally by screws The walls transfer vertical loads and
therefore the longitudinal walls of the upper module are designed to sit on the walls of the module
below
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo)
It consists of a modular structure of high strength galvanized steel which is also used as the
basis for building closure Steel physical properties make it one of the most versatile materials for
construction since it is
ELASTIC Steel does not break as it has a great strength and elasticity It is easily workable and it has
a great advantage over traditional construction
RECYCLABLE Steel is 100 recyclable
DURABLE With zinc application it can become galvanized steel which has extraordinary durability
properties
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
23 | P a g e
Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo)
bull Partially open-sided modules
4 sided modules can be designed with partially open sides by the introduction of corner and
intermediate posts and by using a stiff continuous edge beam in the floor cassette The maximum
width of opening is limited by the bending resistance and stiffness of the edge member in the floor
cassette Additional intermediate posts are usually square hollow sections (SHS) so that they can fit
within the wall width
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
24 | P a g e
bull Open sided (corner-supported) modules
Modules may be designed to provide fully open sides by transfer of loads through the
longitudinal edge beams to the corner posts The framework of the module is often in the form of hot
rolled steel members such as Square Hollow Section (SHS) columns and Parallel Flange Channel (PFC)
edge beams that are bolted together
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported module
(wwwsteelconstructioninfo)
bull Modules supported by a primary structure
Modular units may be designed to be supported by a primary structure at a podium or
platform level In this case the supporting columns are positioned at a multiple of the width of the
modules (normally 2 or 3 modules) The beams are designed to support the combined loads from the
modules above (normally a maximum of 46 storeys) The supporting structure is designed
conventionally as a steel framework with beams and columns that align with multiples of the module
width and provides open plan space at ground floor and below ground levels This form of construction
is very suitable for mixed retail commercial and residential developments especially for residential
units above commercial areas or car parking etc particularly in urban projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
25 | P a g e
Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the lower levels
(wwwsteelconstructioninfo)
o Wood structure
Back in the days of the very first modular buildings wood was the modular construction
material of choice and nowadays it overwhelmingly remains the most used for these projects due
to its abundance and cheaper initial costs Wood-framed modular buildings however have several
notable limitations that might give a property developer pause and may even prove more costly in the
long-term repairs
Wood often lacks the strength necessary to support large building projects especially those
of multiple stories Due to this weakness wood-framed buildings are typically no taller than a few
stories a considerable limitation for someone looking to build a hotel or apartment building as
examples
Wood is flammable and vulnerable to fire which could severely damage the structural
integrity of the building requiring replacement or even worse leading to a total collapse
Wood tends to warp over time resulting in a lower quality building in the years after
completion Combined with its susceptibility to pests and mold selecting wood for a modular
structure may prove to be the more expensive choice in the long term considering repair costsmdasheven
despite initial savings
Wood is among the most wasted materials used in modern construction On average 20 of
construction lumber typically ends up in landfills leaving a larger environmental footprint than other
alternatives (httpswwwdeluxemodularcom)
Considering all those negative points mentioned earlier there are numbers of regions that
still are oriented to wooden structures as this type of housing is part of culture of the society because
of traditional architecture etc therefore typical clients prefer to build the type of accommodation
that they trusted for many years as it became the main demand of market Accessible local resources
availability of necessary knowledge for construction and compatibility of labour forces with this
method are other reasons to be chosen over the other alternatives
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
26 | P a g e
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other metals
(vanguardmodularcom)
o Concrete modules
Precast concrete is a well-established and efficient manufacturing industry and products
range from hollow-core slabs to beams and columns in structural frames Concrete modules can be
manufactured in two ways either from precast 2D wall floor and ceiling panels or as 3D modular
units which are generally cast with an open base Concrete modules are often used in high-security
applications as they are extremely resistant to damage
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma Beton)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
27 | P a g e
Types of modular buildings based on operation period
bull Relocatable Buildings (RB)
Relocatable modular buildings are designed to be reused or repurposed multiple times and
transported to different sites Relocatable Building as defined in the 2015 International Existing
Building Code a partially or completely assembled building constructed and designed to be reused
multiple times and transported to different building sites
bull Permanent Modular Construction (PMC)
PMC is an innovative sustainable construction delivery method utilizing offsite lean
manufacturing techniques to prefabricate single or multi-story whole building solutions in deliverable
module sections PMC buildings are manufactured in a safe controlled setting and can be constructed
of wood steel or concrete PMC modules can be integrated into site-built projects or stand alone as
a turnkey solution and can be delivered with MEP fixtures and interior finishes in less time with less
waste and higher quality control compared to projects utilizing only traditional site construction
Common uses of modular buildings in the market
o Education
Relocatable buildings have become a critical factor in managing student demographics and
increasing enrolments Relocatable classrooms are also ideal for swing space during new construction
or renovation Convenient flexible cost-effective temporary buildings can be delivered and
operational in as little as 24-hours These classrooms are measured for quality and code compliance
by state or third-party agencies through routine and random inspections testing and certification
services Customers may choose single classrooms or arrange multiple buildings in clusters to create
a campus feel MBI members supply steps decks ramps and even furniture Members also offer
lease purchase and lease-to-purchase financing for a variety of public and private school needs
These classrooms are sometimes referred to as temporary portable or mobile classrooms
o Construction-Site
Relocatable buildings have their roots in construction site trailers where speed temporary
space and relocate-ability are important Used as standard field offices construction site and in-plant
buildings are available for immediate delivery Standard construction is wood but steel units are
available to meet non-combustible requirements In-plant buildings are available as single- or two-
story units for industrial environments with noise reducing insulation and are typically moveable by
forklift and include electrical and communications wiring heating air conditioning and even
plumbing
o Healthcare
Relocatable buildings for healthcare applications are designed and constructed to
uncompromising standards of quality A customerrsquos new clinic hospital extension laboratory
diagnostic centre MRI unit dentist office or other medical facility can be open for business and
serving communities in as little as a few days Is your interest in serving patients as quickly as possible
in the safest and aesthetically pleasing environments available These facilities offer quick quiet safe
and clean buildings with an unlimited choice of interior deacutecor and furniture and equipment leasing
o General Administrative and Sales Office
When production demands increase relocatable buildings can temporarily enlarge a current
facility without permanent alterations to the site Because the space is not permanent many
companies are able to expand without the budget approval process necessary for traditional capital
expenses Relocatable offices can be single- and multi-story buildings configured to include
independent offices conference rooms and large open spaces for cubicles or other partition systems
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
28 | P a g e
Large and small businesses as well as local and state governments are typical users of relocatable
office space
o CommercialRetail
Earlier occupancy means quicker return on investment For retail occupancies this can mean
significant cash flow advantages Standard floorplans are available for immediate delivery while
custom buildings are built to specifications in weeks not months Unique to the modular process is
concurrent construction site-work occurs while buildings are being put together in a quality-
controlled factory Typical retail applications include new home sales centers banks golf pro shops
automobile fleet ownerships college bookstores and concession stands If a clientrsquos emerging
business needs are short-term temporary space will accommodate their financial situation space
requirements and deadlines
o Security
Relocatable buildings can be custom built for a variety of access and control situations Toll
booths tickets sales offices guard stands and weigh stations are common applications One and two-
story wood and steel buildings have straight walls or walls that are tilted to improve views and reduce
glare
o EmergencyDisaster Relief
There is simply no other means of providing fast transitional shelter and basic community
needs following natural disasters than relocatable buildings Relocatable buildings can be quickly and
efficiently deployed for emergency shelter medical and educational needs or to accommodate relief
workers
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction report MBI 2019)
Construction phases
Modular construction is the process of manufacturing multiple building sections in a facility
for assembly at a remote building site The building sections called modules will fit together once
assembled on site with plumbing HVAC and electrical connections running throughout One of the
great advantages in the modular construction process is that many of the processes happen at the
same time which can cut the construction time in half There are six common steps to complete a
modular project Design amp Engineering Permits amp Approvals Site Development Plant Fabrication
Transportation and Installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
29 | P a g e
Figure 2 34 - Overlaps of phases in modular construction project
o Step 1 Design
The design phase of the modular building process creates a description of the building usually
represented by detailed plans and specifications A thorough customer consultation with a Palomar
project manager gathers the information required to develop the building plan Once this information
has been gathered the design team will produce the ideal modular building design to fit the customerrsquos
needs
o Step 2 Engineering
Each building design goes through the engineering department for an engineering review Like
site-built structures modular buildings are subject to a series of national state and local building
codes that ensure the building meets a set of standards for safety and performance State level
building codes can be superseded or augmented by local building code requirements and then must
confirm the design proposal meets all applicable building codes
o Step 3 Permits amp Approvals
A construction permit or building permit is a permit required in most jurisdictions for new
construction or major renovations Typical construction permits required can include
Site plan
Building permit
Mechanical permit
Plumbing permit
Concrete permit
Encroachment permit
Sign permit
Flood district development permit
The building owner is ultimately responsible for securing building permits for work on their
property In practice most building owners appoint the general contractor as an authorized
representative so the contractor can obtain the required permits The building owner is advised to
confirm that the general contractor has secured the proper building permits for their project Failure
to obtain the proper permits can result in significant fines penalties and even demolition of
unauthorized construction
o Step 4 Site Development
One of the advantages inherent in modular construction is that the site development and
building foundation are prepared while the modules are being fabricated at the manufacturing facility
and transported to the job site The site development and building construction processes happen
Permits
Design amp Engineering
Site Development
Plant Fabrication
TransportationOn-site installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
30 | P a g e
concurrently instead of sequentially like site-built construction Projects are developed on a variety of
geographic settings typical site development includes
Surveying
Demolition
Excavation
Grading
Site drainage
Foundation construction
Utility installation
There are two primary modular building foundation classifications on-grade and raised or full
foundation An on-grade foundation is generally for permanent installations and is more expensive A
full foundation can be used for temporary or permanent structures it is less expensive to install and
it is more cost effective to relocate the building later while causing minimal site disturbance
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom)
bull Step 5 Plant Fabrication
There are two scenarios for steel modular constructors There are few numbers of off-site
plant which built their own steel frames inside the plant because of high initial budget and it is
common that it would be cheaper to order the frames from another supplier and transfer to the
factory to assembly with other parts The steel frame is then loaded on the main factory production
line where the sub-floor is insulated and floor decking is assembled atop the steel frame As the
module moves down the production line framed wall sections are fabricated insulated and hoisted
in place The truss roof assembly is built in components at ground level before it is hoisted into place
The module proceeds down the line where mechanical electrical and plumbing services are installed
while the last of the insulation goes into place Interior finishes like drywall painting and flooring are
applied while doors and windows are installed
On the last stop of the production line the exterior finish and trim are applied before the
module is prepared for transportation
During construction at the manufacturing facility a third-party inspection agency is present to
ensure the modules are built in compliance with building code
bull Step 6 Transportation
The fabricated modules are shipped over the road by carriers that specialize in modular
building transportation In most US jurisdictions building shipping limitations are 16rsquo in width and
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
31 | P a g e
between 70rsquo amp 90rsquo in length per module Permissible Maximum Dimensions of Lorries in Europe and
UK for Lorry or Trailer are 4m in height 255m in width and 12m in length (International
Transportation forum)
bull Step 7 Installation
A general contractor often one specializing in modular construction will install the modules
complete any on site finish out and make the final utility connections
The choice of building foundation determines how the building will be installed Permanent
semi-permanent and on grade foundations will require the modules to be set with a crane Raised
foundations typically used for temporary buildings allow the modules to be set in place through
simple mechanical methods
With the modules in place final finish out of the interior and exterior proceeds Finish out can
include electrical and mechanical system connection between modules stairs wheelchair ramps
skirting exterior siding trim and utility connections
Literature review on possible advantages
Modular construction comes with advantages which motivates investors and innovative
constructors to apply this method on their future projects Here these benefits are being classified in
various sections such as schedule economic environmental health and safety and social-laboral
advantages
Scheduling benefits
While on-site constructors are complaining about the slow progression of construction
activities and delays on project deliveries the struggle is still to be continued to find new methods to
improve productivity and progression speed while maintaining the quality at a reasonable level
whether if its achievable or not On the other side modular construction because of numbers of
reasons is making a significant boost in term of time management in many phases As it can be seen
in figure 236 McKinsey amp Company report explains that approximately between 20 - 50
scheduling improvement can be achieved in comparison with traditional on-site construction
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method (McKinsey amp Company
2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
32 | P a g e
To be more specific literature reviews identified numbers of benefits in most of the
constructive activities from design to on-site installation As the table 22 illustrates off-site
manufacturing brings most of the time saving to the project by better coordination precise quality
management and not being affected by the on-site bad conditions Table 2 2 - Possible benefits in projects scheduling
In addition design can the ability to be applied in multiple projects instead of just one which
accelerates the project schedule significantly Various overlaps in modular construction can save lots
of time in projects such as site preparations off-site manufacturing and on-site installation with each
other
The acceleration in design process which would be ideal for schedule-critical projects (for
instance emergency accommodation for people who are affected by natural causes) also Long-lead
items can be stocked Fabrication can start and finish earlier in this case In the real state point of view
in the design phase there is one huge benefit which will be so handy when nearly ldquoshovel-readyrdquo
design documentation is needed for clients and site selectors (wwwmcminnvillebusinesscom)
The simplicity precision and clarity of the design plans in modular projects can increase the
possibility of using advanced software such as BIM which reduce the period time of designing phase
significantly With the increasing the possibility of integration of BIM in construction project
incorporating modular building technologies into project becomes more developed and
manufacturing and construction process could be streamlined (Na Lu and Thomas Korman 2010)
About 90 percent of the build activity takes place indoors which means the building process
is nearly guaranteed to stay on schedule That predictability and reliability enable you to count on
timely project completion If a skilled modular crew only spends half the time building your structure
than a site-built crew would your labour cost also gets cut in half
Because of stability of production location there are numbers of advanced technologies
which are being used in other industries production lines that can be used in these off-site facilities in
order to improve the productivity and reduce the timeline of the activities
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
33 | P a g e
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom)
The nature and outdoor construction have always mutual effects on each other mostly in a
disfavour way Site conditions often cause negative impacts on the activities which lead delays quality
insurances or stop them because of safety matters In result the project schedule can be changed and
most of the times unpredictive delays will take place in the timelines In addition there are sites which
the possibility of on-site construction for most of the year is almost zero percent or if exists would be
limited because of life risks for workforce A reasonable solution for these cases is off-site construction
which in most of them reduce the nature effects Thus factory-based production can make a
revolutionary impact on the project scheduling In modular method 60-90 of the construction work
is completed in a closed factory environment and this mitigates the impact of unfavourable weather
(FLORI MURESAN on ny-engineerscom)
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
34 | P a g e
Machinery equipment can take place in mentioned phase instead of human labour which can
boost the productivity quality as well as the time reduction Robotic assembly is one the efficient
examples of this technology One of the very first EU projects carried out in the Robotics Lab
(httproboticslabuc3mes) located at the Carlos III University named FutureHome-IF7 project The
done research was focused in the robotization and industrialisation of the final stage of the
construction process by mean of modular construction (Martinez 2008)
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes)
Economic benefits
Economic advantages can always attract investors to develop innovations Since in a project
time and cost have a direct and mutual relation with each other most of the benefits which were
mentioned earlier in the schedule section can also make positive impact in projectrsquos economy In
some cases these benefits equal to the initial costs which will be discussed later in challenges As it
was mentioned earlier the design plans can be repeated multiple times in projects because of
similarity of requirements that can save design costs in future budgets
Modular building because of their standardization and classification in design phase can be
more compatible with advanced such as BIM (building information modelling) BIM technology in its
5D phase does cost estimating material quantifications and pricing to be automatically generated
and modified while changes are applied for each building module (Na Lu and Thomas Korman 2010)
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
35 | P a g e
Foundations do not have complexity in modular buildings because of weight of the modules
which have to be manufactured lightly in order to be transported simpler to the location
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk)
Also because of the high quality and precise off-site execution there are fewer reworks in
modular products which can save costs in projects Off-site manufacturing provides more economic
benefits such as reduction of salary wages due to a smaller number of workers and more specialized
ones and adding values to each hour of work by increasing productivity to the activities
Moreover massive orders of Materials to the supplier can bring more quality to the material
multiple discounts on each offer and add more stability in prices of material in instable markets Table 2 3 - Economic benefits in modular method
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
36 | P a g e
Environmental Benefits
A highlight among the modular constructionrsquos benefits is in the environmental point of view
Since the modular buildings are friendly with environment many clients are willing to change their
method to this ecological approach in order to make their projects more sustainable and promote
their product in the market as an innovative constructor in the industry such as ldquoGrupo Consentinordquo
which not only builds modules that are available to use solar panels as energy supplier but recycle
many structural and non-structural elements and reuse them in another projects Waste management
can be applied simply in modular construction by reduction in waste during off-site production recycle
and reuses in elements in several projects use of automation can secure waste reduction at a high
rate It has been proven that modular construction can reduce waste by up to 90 thanks to off-site
construction (JAHNAVI SAJIP ny-engineerscom)
Agostinho Mendonccedila in 2018 did a research about reuse in construction industry which
shows a great improvement in terms of sustainability During 2022 FIFA World Cup in Qatar football
fans will have the opportunity to enjoy the stunning views of Doharsquos skyscrapers and be marvelled at
the unique Ras Abu Abod Stadium Its design concept results in a good cost-efficient arena with an
elegant curved square form
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images)
This innovative stadium will also allow it to be completely disassembled after the World Cup
Precisely many elements of the arena including all 40000 seats the containers and even the roof
will be reused providing valuable infrastructures to sports and non-sports projects elsewhere
Moreover off-site manufacturing can reduce emissions much more than conventional
method In 2009 Al-Hussein et al focused on the construction phase of modular and conventional
buildings and compared their CO2 equivalent emissions They analysed a 42-suite multi-family four-
story residential modular building located in Alberta Canada All the construction activities needed
for this building and a similar conventional building such as material delivery transportation
workforce trips equipment usage and winter heating were identified separately Therefore CO2
emissions from each of these activities were quantified The authorsrsquo analyses showed that modular
processes led to a 43 reduction in CO2 emissions compared to on-site processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
37 | P a g e
Table 2 4 - Environmental Benefits
While the on-site construction disturbs the sitersquos neighbourhood with noise dust congestion
and waste modular construction performs better by providing minimal project site disturbance
(Mohammad Kamali2016) Since most of the construction process takes place offsite there is less
impact on the project surroundings Modular construction reduces the number of vehicles and heavy
equipment required on site which translates into reduced pollution and less site disruption
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site (wwwcadoltocom)
Energy consumption in the occupancy phase of modular buildings dominates the other life
cycle phases This phase alone accounts for more than 70 and up to 98 of energy consumption and
consequent impacts over the life cycle of buildings while the contribution of the construction phase
is relatively small (M Kamali 2016) Sustainable material selection optimum modular factory
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
38 | P a g e
location and availability of labour which lead to less embodied energy consumption are effective
opportunities to reduce the life cycle energy consumption and the subsequent environmental
impacts In addition a smart design of insulation which is advanced in modular buildings can achieve
a high amount of energy use saving during the operation phase
Figure 2 44 - various layers of a module building unit including insulations (wwwsteelconstructioninfo)
Health and security benefits
When it comes to safety modular method can offer advantages for both phases (construction
and operation) to workers and future users Converting possibly dangerous on-site activities to an off-
site plant that there the supervision and control is much higher can reduce the accidents for the
workforces and the products It is obvious that the safety plan can be applied much more efficient in
a factory environment Not only is there a reduced risk of slips trips and falls ndash particularly as work
at height is reduced but there is also a reduction in onsite activity thus ensuring health and safety
always remains a top priority from start to finish
Furthermore if necessary factory operations can continue 247 with less risk of noise and
disruption to workers Work is also unaffected by the weather and other environmental delays which
could result in the project being turned around even quicker
On the other side during the operation phase safety can be improved for instance fire
protection can be designed by using multiple insulations and protectors inside the panels
One of the examples is Actavorsquos plan for Ensuring everyonersquos safety is at the heart of Actavo
what does and in line with this they have developed the HEART (Help Eliminate All Risks Today)
procedure Devised and implemented in the continuous effort to create an accident and incident-free
environment the HEART behavioural safety observation process sets the whole Actavo teamrsquos
expectation every injury is preventable so do not let any happen (Hannah Vickers b4edcom)
Modular construction generally achieves these requirements using fire-resistant plasterboard
conforming to BS EN 520 Alternative materials such as cement particle board and gypsum fibre board
may also be used in combination with plasterboard as the facing layer In residential construction
each dwelling usually forms a separate fire compartment All walls and floors that provide a separating
function between compartments require 60 minutes fire resistance In hotels and other residential
buildings each bedroom may form its own compartment (wwwsteelconstructioninfo)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
39 | P a g e
Figure 2 45 - Compartment floor at junction with external wall and compartment wall (wwwsteelconstructioninfo)
Social-Laboral benefits
Most of the mentioned benefits including economic scheduling environmental and safety
advantages have direct effect on social well-being as well Therefore they can also be named in this
section Future users can benefit from the quality of building energy savings etc which leads to
costumerrsquos satisfaction among the public Due to the shorter on-site schedule there are fewer
negative impacts on local businesses urban beauty image than conventional constructions Also
modular construction demands more skilled workforce and experts which can create more jobs for
these group of labour in the regions that struggle with high unemployment rates
In addition every industry needs to trust innovations in order to improve the science and help
the innovator to break limitations and explore new alternatives to solve problems Modular
construction as it was mentioned can be a great solution for the productivity problem in construction
industry and by applying these method it is possible to even find more solutions in the future which
can increase these rate more or solve other problems that nowadays are common among players of
construction industry Table 2 5 - Health and safety amp Social-Laboral advantages
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
40 | P a g e
Modular Construction role in COIVD-19 Pandemic
Recognizing the urgent need to create modular critical care units for rapidly growing numbers
of COVID-19 patients HGA Architects and Engineers partnered with Boldt Construction to design and
build a new system within a noticeably short timeframe ldquoThe initial idea was to provide rapid
response for hospitals and build a product with off-the-shelf readily available parts because we did
not know what the supply chain would be like Over the course of three weeks we went from concept
to full design and fabrication was underwayrdquo reports Ben Bruns executive vice president of Boldt
Construction in Appleton Wis (Rapid Response by Barbara Horwitz-Bennett 2020) The final product
was a prefabricated modular solution for assembling field hospitals capable of providing airborne
infection isolation rooms
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use inside convention
centres arenas and temporary structures Image courtesy of HGA and The Boldt Company (prismpubcom)
These Strategic Temporary Acuity-Adaptable Treatment (STAAT) units are isolation units with
enough clearance for safe bed transfers and accommodate equipment and a reclining chair These
multifunctional modules can be used as supplemental interior isolation rooms within an existing
system of care as a modular system connected to an existing hospitalrsquos infrastructure or as a self-
sufficient temporary hospital with its own infrastructure
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The Boldt Company
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
41 | P a g e
PCL Construction has come up with a similar solution in collaboration with Thor Plumbing and
Heating f-BLOK Architecture EH Price Industries and P4 Electrical Contractors Called ldquoQuaran-Tin
Podsrdquo the units are emergency response modular isolationcare rooms that provide temporary and
reusable emergency isolation for care and treatment of COVID-19 patients Each unit is self-contained
with built-in power heating and cooling as well as connections for medical gas oxygen and vacuum
Highly scalable and customizable the pod is continuously negatively pressurized and all the exhaust
is HEPA filtered Citizen Care Pod is a smart screening and testing pod that integrates intelligent
technology within a modular design to support a safe responsible recovery for governments
businesses and communities Customizable with the capabilities to enable full-on mobile COVID-19
testing in high-traffic environments the project will help in testing screening and eventually
vaccination on a mass scale (Christele Harrouk on archdailycom)
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction (archdailycom)
The Citizen Care Pod is a turnkey solution that accelerates recovery for businesses and public
institutions such as airports offices sports and entertainment complexes construction sites and
more by rebuilding staff and customer confidence that your organization is equipped to ensure their
safety
Unfortunately the COVID-19 pandemic is only intensifying the housing crisis Further
complicating the issue is the fact that a significant percentage of skilled labour workers will be retiring
within the next couple years which will significantly impact the construction industry As stated in
MBIrsquos ldquoThe US Construction Industry A National Crisis Loomingrdquo there are currently not enough
skilled workers to build all of the projects that need to be built in the same manner in which they have
been built in the past ldquoThere is no other choicerdquo advises Hardiman ldquoIt is now time for our
policymakers to start looking at alternative ways to build everything and we think that modular
construction should be a part of that solutionrdquo Along these lines the COVID-1 Response Page also
includes links to articles illustrating how MBI membersrsquo systems and facilities are currently being used
in housing infrastructure and COVID-19-related projects
Review on common challenges
Initial costs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
42 | P a g e
To start the modular construction method in an area there will be a significant investment
to establish a production plan and then designing team who must work alongside the execution
engineers parallelly in the design phase
factory cost Like any other industry modular construction demands a production line which
is an off-site plan with a supply chain based on 3D volumetric products First the off-site plan must be
designed based on the local requirements amount of demands availability of experts and labours and
budget that manufactures are willing to invest on this technology These factories are mostly
expensive to be build and the issue of production costs will always be a barrier to innovation in
modular construction because both the client and the architect will expect lower fabrication costs
However the art of every industrial innovative player is to study the economic pros and cons
of issued technology and then the industrial expert by doing couple trade-offs between the benefits
and disadvantages can make the decision whether to apply the new method or not Modular
construction is not an exception of this fact A local study can tell the investors if the approach would
be reasonable in all term and not only economic terms for the society or not Thus due to the
economic benefits that were mentioned earlier in numbers of regions which the labour salaries are
higher and the balance between transportation costs primary material access and costs experts
existence local market and their demand of real state and initial costs is more favourable modular
construction can be the best solution to apply On the other hand nowadays there are numbers of
region which the investors of industry are eager to use innovative method with higher costs that have
positive influence on environment and public health in which modular construction is more friendly
than the conventional method
Figure 2 49 -Balance between Initial costs and Economical benefits
First design costs and errors By changing the traditional construction products a change of
design is also demanded Modular design can be based by the production linersquos technologies the
budget of manufacturer and the final products quantity and quality In the earlier discussions about
design phase the complexity of 3D volumetric design had been mentioned and surely in the first
attempts would be expensive for the manufacturer However if the design could focus more on the
standardization of elements repetition in production line and consider integrate with modern design
software in order to provide more executive details and minimize the future errors and reworks the
rework cost can be eliminated and the design sample can be used for numbers of projects as a
catalogue with few changes Therefore by having these advantages the initial design cost can be
recovered soon and even make more benefit by the time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
43 | P a g e
Architectural challenges
One of the main group of experts who have argues about modular buildings are the
architectures who always suffer from limitations that this approach puts on their design process Most
of these challenges are mentioned below
bull Manufacturing technologies effect on the design One of the challenges which the manufacturers
can struggle is to consider a production line that be able to produce a wide range of product so
that there will be fewer limitations on the design phase This goal can often be impossible because
of the predicted budget of investors limited area of production plant and lack of technologies
Thus it is the architect who must be flexible with the production line and its boundaries
Moreover it is the art of the architect which can maintain a balance between ability of production
line and attractivity and innovation of the final product for the market and the industry
bull Transportation boundaries on architecture It is a fact that the transportation of modular
construction have puts limitations on the architectrsquos works The modules must obey the
obligations and regulations of the region that want to be transported in Therefore architects
must design modules which are transportable and minimize negative economic and timing effects
for the project In addition in the designing process environmental aspects which can be
happening during the transportation phase must be considered
bull Regional architecture specializations There are cases in which an off-site production plant ships
same model of modules for numbers of projects which are going to be assembled in variety of
regions with different climate cultural architecture and local construction regulations which can
surely have negative effects on the regionrsquos construction industry real estate market and cultural
architecture aspects For instance the harmony of the angel of sunlight and the windows
formation and dimensions in a residential building located in eastern region and western ones
which reduce or increase the sunlight absorption inside the building for the residents In this case
if the same form of modules will be transported and assembled without of any changes the
unsatisfaction of future users can be increased and in a result the demands can be reduce
significantly which could cause a failure for the real estate and construction industry of the region
In terms of architectural culture modular manufacturers must consider the traditional
architecture of the location in the designs in order to make sure that the harmony will be kept
among the present buildings and modular ones
bull Lack of knowledge about modular buildings among architects Manufacturers argue about the
lack of enough knowledge of architects about the modular fabrication process The third-party
inspections and approval process Transportation methods and its boundaries Onsite assembly
procedures The cross section of a modular structure which can reduce their understandings from
manufacturerrsquos demands of project and result a unsuitable design for the final products These
disagreements come with every innovation in civil engineering society which architect must follow
their lead most of the time The solution for this cause is to educate the architects by planning
workshops by the manufacturers or internships during a project so that architects can improve
their knowledge and gain actual experiences by observe and participating in real projects
bull Unfeasible on-site finishing Common architectural innovative designs focus a lot on finishing
works in order to gain attentions of buyer and improve attractiveness of buildings There are
different views about this subject Some manufacturers think that the finishing process must be
as simple as possible or minimize the schedule and costs on-site to benefit from the project On
the other hand architects believe that the modular buildings are not attractive enough because
of repetition in their design and try to focus on finishing process to make them desirable to the
market or improve the products in architectonic point of view
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
44 | P a g e
Transportation challenges
By transferring most of the construction activity to the off-site plant transportation plays a
vital role in the projects so that in case of poor logistic management can damage numbers of benefits
which were achieved in the factory plant
bull Dimensional and weight barriers based on type of transportation The type and technologies of
every modular constructorrsquos logistics can affect the project from the design phase to the on-site
assembly These effects can change the dimensions weight and structural features of the product
For instance modular structures transported on a flatback trailer will be limited in length width
and weight based on the physical capacity of the truck Components fit into shipping containers
are best suited for projects overseas because the structural integrity of the containers allows for
unorganized stacking However components will be limited by the interior dimensions of the
container in length width and height (Joseph M Schoenborn 2012)
bull Long distance transportation and lack of existence of local factory Off-site plants are not
available for every site location in numbers of states or even regions yet because of poor
development of these method in those regions Therefore in some cases the modules must
shipped even overseas to the site location to be assembled Long distance and its possible
difficulties during ground or marine transportation can bring extra costs for the project which
must be studied economically before the biding process
bull State regulations on structures dimensions and strategic issues Estate laws can always put
boundaries on construction industry and modular constructors are not an exception Every region
has its structural and transportation regulation which limits the final product In addition estate
approval during transportation phase can harm the projectrsquos scheduling program and put delays
on the arrivals or even occasional penalties which causes extra costs in the budget
bull Negative effects from environment on the modules during the transportation While the
modules are being transported to the site these products are in direct exposure to the
environment such as sunlight rain wind and other natural causes By the time possible damages
can be appeared in the modules which in some cases can be too critical that module need to be
repaired or replaced to be used On the other hand ground transportations can cause vibrations
on the trucks and its loads and the intensity of damage generally increases with the roughness of
the road surface which in some creates cracks or more critical damages on the structural element
installations or finishing The solution is to use To minimise transportation difficulties the vehicle
having vibration absorber can be used to minimise damage due to vibration and additional
precautions need to be considered for wider modules while low bed transport vehicles are
preferable for transporting taller modules (W Ferdows 2019) Moreover loading and offloading
processes must be carefully done by precise strategy and adequate equipment in order to avoid
the harms on the products
bull Transportable materials There are two terms which force modular constructors to use advanced
and high-quality materials transportation and design situations Transportation as it mentioned
earlier puts limitations on the final product and force the constructors to use material which have
less weight more against resistance road vibrations and endurance against sunlight and humidity
exposures In one word these materials must be part of a final product which can be
transportable Often these materials add costs on the project because they are more expensive
than the ones which have been used in conventional buildings All properties need to be
structurally sound in situ but units built using offsite construction methods also need to be
structurally sound whilst being raised and lowered throughout the transportation and assembly
stages of the process Key structural elements such as beams columns and potentially walls and
floors must be repeated in three-dimensional modules for transportation purposes This can
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
45 | P a g e
significantly increase material costs depending on the material choice and level of design
optimization (McKinsey amp Company 2019)
On the other hand numerous benefits which modular construction has in terms of material
such as less reworks discount on massive offers no exposure to natural causes and its off-site storage
and less waste during the production can assure the constructors that these challenges can overcome
the fact that modular buildings work better than conventional ones in a material criteria
Wrong perceptions among public and real estate market
Innovation without correct publicity brings wrong perception among people and markets
Also errors bad experiences of users and unprofessional works can change the mindsets quickly by
unsatisfying the users and in result investors During a period in past off-site accommodations were
mostly for temporary uses with low quality material and less functional features The demands of
permanent housing raised after a break such as world wars for those who lost their houses and
refugees that wanted to live abroad Therefore numbers of companies started to modify their off-site
products in order to have more lifetime and serviceability However there were constructors who
could not provide buildings with better functional services and the users became unsatisfied and lost
their trust in these products This wrong perception had been raised even until now that off-site
building such as modular ones will not serve a long lifetime and have low quality material incommode
and unattractive design and a poor functionality Obliviously bad perception of people will reduce the
demands and destroys the market as well
Today the industry recognizes the need for durable construction for even temporary uses
making it possible to move and re-use full buildings So a lack of knowledge among consumers as to
what is possible can prevent design innovation In order to overcome the stigma sometimes associated
with modular construction manufacturers attempt to offer a built product indistinguishable from one
built onsite Therefore the industry advertises a direct alternative to onsite construction In a
comparative analysis of the two processes time savings and worker safety stand out as the primary
advantages of modular construction over onsite construction The building manufacturing process
itself construction in a controlled environment with access to advanced technology is an evolution
of the art of building which is traditionally slow to evolve The modular building industry therefore
should advertise a different building product altogether featuring design innovation and ingenuity
executed through advanced building techniques (Joseph M Schoenborn 2012)
Moreover in order to raise the demands among the public who can be future users a range
of positive publicity about the environmental advantages such as less emission economic savings like
less energy bills cheaper and easier maintenance processes during the operation phase and faster
construction process which help them to be accommodate sooner can create a positive mindset
among the public In addition post-sell services from constructors such as better assurance policies
for buyers maintenance services and offering loans to customers who are in emergency
accommodation needs can change the market significantly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
46 | P a g e
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects (casasinhauscom)
Integration of advanced software
As it mentioned before modular construction can benefit from using innovative software in
their designing phase in order to be more precise on planning and provide detail for the production
line One of these software programs is BIM which can be used in design construction phase on-site
assemble and even operation phase However despite its advantages there will be some challenges
as well The greatest challenge of using BIM in construction project is the implementation process
itself regardless of the software capabilities Development of accurate BIM model requires extensive
resources and in-depth knowledge of construction methods and process Most small or medium firm
could not afford the special team and man hours to aligning BIM (Na Lu and Thomas Korman 2010)
Other than finance and organizational issues the project team has experienced legal challenges as
well The use of BIM technology encourages multi-disciplinary collaboration which contrasts to
defining responsibility to each party and then assigning liability issues among the parties In addition
using BIM models instead of traditional contract documents raises questions on insurance coverage
and confidentiality exposure Ownership and control of the model use and distribution of the model
and intellectual property rights are some of the issues that need to be addressed while BIM
implementation being adopted in construction industry
Redefining the contracts
Due to the changes over the responsibilities of every participants the amount of their
influence on projectrsquos activities and transferring most of the work to the off-site plant a new way to
contracting is needed in order to optimize the relationship between the owner designers and
manufacturers during all phases of the project Here are some of the common types of contracts which
are being used among modular building industry
bull Design-build The architect modular manufacturer and onsite general contractor are
hired as a team and assume the responsibilities of design and construction together DB contract can
be named one of most traditional types of contracts that would create an integration between all the
parties of a project Due to the design-build nature of modular construction a close partnership is
demanding during the project phases
bull Design-bid-build After the architectrsquos design has been approved by the client a
competitive bidding process takes place This results in a greater disconnect between parties The
common gap between participate happen a lot in this type of contract which frequently can cause
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
47 | P a g e
misunderstandings about responsibilities of each expert incomplete information about the project
design or executive details and lack of transparency among the participants
bull Negotiated bid The modular manufacturer is hired first by the client to find the
appropriate architect and onsite general contractor that can be hired within the constraints of a
budget This concept may increase bonding between experts and improve everyonersquos understandings
about many aspects of the project But the budget will decide whether the quality level design
enhancement can meet the clientrsquos requirements or not In addition in case of clientrsquos approval the
question would be the future userrsquos satisfaction can be achieved or not due to the budget limitations
on the project quality level
bull Certified Modular Architect (CMA) A sustained relationship between an architect
and a manufacturer can be developed over multiple projects Therefore a certification process
providing training and continuing education can be introduced to the modular building industry An
architect intimately familiar with modular construction is best suited to handle coordination issues
that arise when work is being done in the factory and onsite simultaneously A it mentioned earlier
architects understanding and knowledges is critical to avoid possible mistakes and unsuitable designs
for modules Therefore this certified education which can be called as a semi-professional internship
for the design team in order to be present at every phase of the project
Supply chain-transportation-onsite assembly management errors
One of the main objectives to use prefabricated elements in construction is to raise the
productivity in execution phase which is mostly happens in off-site plant As it mentioned before there
is a supply chain in manufacturing plant and its productivity is depended to many key factors which
will happen outside of the factory Continuity of assembly operation is one of them which would be
happening in parallel with off-site supply chain After the modules were prepared to be transported
to the site the transportation system must be synchronized with the factory delivery and assembly
demands If any delays may happen during the transportation would affect the both origin and
destination scheduling storage policies and demands
On the other hand assembly line also must on-time and well-communicated with off-site
plant experts because any changes in execution phase can make huge negative impacts on supply
chain productivity Therefore these three important phases must plan based by on-site demands
supply chain productivity execution management and transportation systems
Figure 2 51 - synchronization between supply chain transportation and on-site assembly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
48 | P a g e
3 Common challenges in modular construction industry by a
survey Methodology
Objective
This study used qualitative research and specifically a grounded theory methodology to
uncover more information about advantages of modular construction and its constraints or barriers
to develop this method in the market Qualitative research emphasizes the influence of the researcher
on the data collected
Role of the researcher
In this study I acted as the sole researcher who was responsible to design questions based by
literature reviews and then by creating an online survey form try to collect the data from the
participants
Ethical considerations
To protect the rights and guarantee the safety of participantrsquos information following actions
were done
1) The research objective and process were made clear to the participants
2) The collected data was used for research objectives only
3) Only eligible participants who are modular constructors and manufacturers were
chosen for this survey
4) The access option to the survey information gave to the participants after the
research was finished
5) The anonymity of the participants was maintained
6) The name of the participant and their brand was remained confidential for all roles
even the researcher to obey the law of data protection
Survey setting
Due to the emergency restrictions which caused by a virus pandemic across the world several
options were unavailable to be done such as face to face interviews factory visits and project site
practices Therefore online interview was the only solution which can be happen without any danger
for participants and researcher In most regions construction companies are suffering from a full shut
down on their production line and on-site projects so that access to these participants became even
harder than usual Thus an online survey form by office forms was chosen for this research so that
the participants can answer the form questions at any time and location with ease to answer by
multiple accesses to the formrsquos link (Figure 31)
This survey forms had been sent by email to the official addresses that were mentioned in
their websites for contact The priority in choosing the recipients were the construction managers
project managers and executive engineers so that the information will be collected from the operation
managers who have the most technical experience and have the most knowledge with construction
phases from off-site production to on-site installation This could also help the survey to find the
challenges during the construction that were not able to be visited due to the restrictions of global
pandemic
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
49 | P a g e
Figure 3 1 - Online office forms for survey use
The estimated time was reduced to 13min with the most important questions to improve the
efficiency and be timely reasonable for the participants
Development of questionnaire
After hours of study on numbers of articles which have focused on challenges in modular
construction industry several were found that have lack of scientific scope and recommended
solutions Therefore many of the questions were designed to first shed a light on the potential
advantages which have not been mentioned specific and completely unknown for the industry For
instance the social benefits which came immensely useful during the COVID-19 pandemic for health
centres and medical infrastructure etc Moreover a lack of inconsistency between industry and
science came to notice which shown a massive gap between these two important roles in construction
industry This gap explains that the scientific researchers in some areas have the minimum contact
with industrial players in construction world in comparison with other industries which the opposite
situation is applied To fill this gap questions were designed in a way which have an origin of scientific
researches and direct and first-hand information from the construction industry players which are
constructors modules manufacturers etc
Development path of questions can be explained as critical path to the best details of each
criteria than can obtain useful information from participants In terms of advantages the benefits
which were identified from literatures were ordered and asked form participants to be confirmed and
validated by the industry players in real project cases For instance in an environmental point of view
Reduction in Energy Consumption was identified in literatures and had been asked among participants
to confirm the hypothesis that modular construction can reduce the energy consumption in
comparison with traditional methods (Figure 32)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
50 | P a g e
Figure 3 2 - Questionnaire development
Participant profile
Experience amp professions
As the ldquoTable 31rdquo explains information from five companies have been selected for this
survey with variety of backgrounds from pioneers to well-experienced players in industry with over
than 120 years of experience in the modular construction society as constructors and modular
manufacturers The experts who answered have different roles in the industry from CEO to architect
and sales managers so that the data can have more perspectives of views on the questions such as
sales market and design process to project management Table 3 1 - Participantrsquos profiles
Because of diversity in the influence of challenges between massive international builders and
local players these five companies responds have been compared to each other from company C
which is a local constructor to company E that is currently executing modular projects in 80 countries
with approximately 6000 modules build annually
Types of materials in some cases can have different statistics in results For instance in
modular construction which steel and wood modules are more often used in projects can produce
various amount of CO2 emissions and waste or recycle process can be done with more ease For that
reason these survey all types of materials are considered including steel modules concrete modules
and wood modules There is also an argue that some benefits and challenges cannot be seen in unique
projects with more repetition in production of elements and mass production such as hotels and
schools while in residential projects can exists more than the others To cover all the contrasts of
60 of participants
can acheive a 30-40
reduction energy
consumption
A Our homes are not positive from an energy
perspective
B We can finish a 4 months traditional project in 8-10 weeks and Energy consumption of a factory is known and relatively constant on a weekly
E 30 reduction in energy consumption
Modular construction can
reduce the energy consumption up
to 30 in compariosn with
conventional methods
QsCompany A B C D E
Years of company experience 10-15 10-15 20-30 20-30 30-50
Position of participant CEO Sales Manager Design Architect Quantity Surveyor Foreign Trade Manager
Professional experience 15 13 30 NA 3
No of employeesfactoryModules build annually 801200 1301490 151- 50280 25026000
Type of material(WoodSteelConcrete) W amp S W W W S amp Conter amp fiber cabins
Types of Projects (ResedentialSchoolsHospitalCommercial) R R amp S amp C R R amp S amp C amp H R amp S amp C amp H
Use of BIM Yes No No No No
Level of automation 20 reaching up to 80 20 Off-site 60 On-site 20 20 60
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51 | P a g e
information these companies have been selected that are involved in all types of modular building
projects including residential hospitals schools and commercials buildings
As it mentioned before BIM program can advance the projects in many ways however
unfortunately among these participants only company A is able to benefit from this software from 0
to 100 of the project Therefore the further arranged interview focused on BIM Function was
cancelled and may be done in the future investigations
Automation can play an important role in improving the productivity and sustainability of
construction processes as a part of ldquoindustrialization in constructionrdquo movement Among survey
participants the minimum automation level in off-site plants is 20 and maximum of 60 and in on-site
activities can be up to 40 In addition company A claimed that in near future their automation can
reach up to 80 which is an innovative move in construction industry On the other hand company
with over than 6000 modules build annually have a significant 60 of automation in their plant which
shown a massive interest of investment on this technology In addition automation application
difficulty have direct relation with the type of materials used in modules and type of the projects which
as Table 31 illustrates company E with the most variety in project types and materials use have
achieved a huge success in application of automation with a level of 60 which also helped a lot to
expand their market overseas
Data collection
General information
All the received information has been attached in ldquoAnnex 1rdquo where the responds are not
edited and mentioned in the original shape Here are the shorter versions of responds
bull Motivations to choose modular construction over traditional
To bring the attention of investors to an innovative method reasonable motivations are
needed which can be the current demands of market economic profits and environmental benefits
Therefore it was necessary to identify the motivations of these companies to start a modular
construction form Economic advantage for most of these has a priority not just for being profitable
but for being able to develop their dominance in the future On the other hand innovation has an
approximately same amount of interest which explain the reason behind choosing modular method
that is one of the most innovative off-site construction methods in the industry
The fact that mentioned before in literature reviews high demands in the market and the lack
of provide by construction players is one of most important reasons to apply a fast and high-quality
solution for reach the satisfaction of housing market Shorter schedule and environmental benefits
took the next places of priority in motivations for these companies which are also important for sure
Figure 3 3 - Participants motivations to start a modular company
28
9
18
18
27
Economic benefits
Enviromental benefits
Shorter schedule due to the need
High demands of housing in themarket and lack of provide
Innovation
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52 | P a g e
bull Built in factory panelssubcontracted panels used in modules
All five companies are manufacturing the panels that used in modules by their own inside the
off-site plant which as it mentioned earlier the selected participants have a variety of production rates
and by this information that they are able build their own panels it can be said that their production
is 100 off-site However in the case of company E which is a massive international modular player
there are some types of modules that are being provided from domestic market because of economic
feasibility issues
Economic issues
bull No of labourLess wages of salaryAdded value in each hour of workneed of
special workforce
Generally the participants mentioned that there fewer number of workers are needed on and
off site in comparison with traditional method About the amount of salary wages company A
confirms that for each hour of work off-site less amount wages are being paid to workers On the other
hand the shorter schedule of projects in modular projects can reduce the payments as well The fact
that most of the participants are emphasizing is that the efficiency of work and added value of
activities off-site are much more than the on-site traditional projects where company A acclaimed
that in terms of efficiency ldquo1 hour in the factory is equal to 4 hours on-siterdquo
Environmental status
bull Life cycle duration of products and material recycle
Company B acclaimed that they do have multiple solutions for each materials that theyrsquore
using in their modules for instance the unusable drywalls and PVC materials which they send for
recycling or the woods that would use into mulch products or for heating by others
Company E told that their products have a 50 years life span which is the same as a lifetime of
traditional build residential house However company C have some difficulties in recycle and reuse of
their elements because of unportable feature of their products
bull Integration the modules with other innovative technologies
Four of these five companies confirmed that their products have the option to integrate with
other innovative technologies such as self-powered homes by solar panels and also using advanced
insulation technics made by non-petroleum materials in their panels to reduce the energy
consumption during operation phase
bull Waste reduction
Company A acclaimed that their production line generates significant amount of 70 less
waste in comparison with traditional method The rest of the companies focused on carbon footprint
reduction and were able to reduce it 15 less that traditional method by choosing environmentally
friendly technologies in production and wise choice of materials for their products
bull Reuse of structural and non-structural elements in projects
Three of five participants confirmed that they have the ability to re-use their products in the
next projects in order to reduce the waste and energy consumption during the manufacturing
processes Type of the projects and material have the direct relation with the potential of reusability
in elements and due to the variety that the participant have in both criterions the potential is variable
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
53 | P a g e
Figure 3 4 - Re-use potential
bull Reduction in Energy Consumption
Company E mentions that modular construction can achieve a 30 of energy saving in
comparison with traditional site-build method while company A acclaimed that their homes are not
positive from an energy perspective Company B gave more details on energy consumption by making
a comparison between off-site activities and on-site traditional construction and acclaimed that due
to the shorter schedules in off-site production energy consumptions can be reduced up to 50 They
mentioned that ldquoEnergy consumption of a factory is known and relatively constant on a weekly
monthly and annual basis A competent and experienced modular builder can many times finish the
entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-
built house could require as much as 4 months for the same completionrdquo
Social Benefits
bull Delivery of projects for emergency services during COVID-19 Period
As it mentioned earlier due to the virus pandemic that is happening at moment in all around
the world a rapid response is needed more than ever for emergency services for health organizations
and according to this survey one of these companies is providing products for this cause which can be
a good news and accounted as a social benefits for this method of construction
Figure 3 5 - Contribution in Covid19 epidemic
bull Providing post-sale services for clients
In contrast with conventional construction which just have the responsibility until the delivery
of the project modular constructors because of their industrial profile have the ability to offer post-
No40
Yes60
Reuse the structuralnon-structural elements projects
No
Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
54 | P a g e
sale services to the clients such maintenances upgrades etc due to the results of this survey four of
these five companies confirmed the availability of post-sale services for their clients
Figure 3 6 - Post sale services por future clients
Initial costs
bull Initial investment and its Payback period
Company A claims that their initial investment to establish their company was about 20 million
Canadian dollar and its payback period was 5 years Company E had the amount of 15 million USD with
the same 5 years period However company C like many of the older players in modular construction
industry who started way earlier cannot estimate their initial investment
bull Factors that can change the initial costs
There are factors which can make a change in initial costs of companies The participants
prioritized these 6 chosen factors starting with product types and production range with 31 of
importance among others Level of automation took 25 share of the pie chart which has direct
relation with the initial costs Off-site plantrsquos location has 19 of efficiency on starting costs and
furthermore the quantity of sub-contracted players in the projects achieved 13 of the graph Finally
financing and design enhancement have the minimum equal shares of 6 which despite of being the
last factors have the efficiency on initial costs as well
Figure 3 7 - effective factors in initial investments for start-up companies
6
25
31
13
19
6
Factors that effect on initial costs
Design enhancment Level of automation
Product types and production range Less sub-contracted
site location Financing
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
55 | P a g e
Design limitations
bull Design boundaries caused by production line
Company A mentioned the subassemblies as the main element to be considered in design
phase while company D and company B introduce a maximum dimension for their production lines to
be economically viable for transportation costs In addition to those company C and company E
confirmed that there are no boundaries for the designer caused by the production lines because of
their wise choice of prefabrication methods
bull Lack of knowledge from architectsdesign engineers about production processes
transportation limitations etc
One of the main problems of start-up companies and the experts who join the modular
construction industry is the lack of knowledge about off-site processes and transportation limits
Three of five participants confirmed that there is lack of knowledge in these area from designers
Figure 3 8 - Lack of knowledge among designers and engineers
Transportation Limitations
bull Transportation regulation effects on modular projects
Three of five participants confirmed that the regulation by transport administrative can be
harmful for the projects such as extra costs or time delays on schedule Company A mentioned the
time delays in giving permits to the manufacturers and constructors which can damage the
synchronization between production line and on-site installation by reducing the speed of
transportation of elements to the site Company B added information about transportation system of
some states in America which use the term ldquoSuper Loadsrdquo to put limits on oversized shipping that
increases the cost and time on the project On the other side Company C as a strategy to avoid this
problem used legal load limits in their design instructions so that their products will obey the
regulations
bull Transportation boundaries on material choice and project costs
Company B D and E confirmed that the terms of special transportable material will not add
extra costs on the project Company A acclaimed that the extra costs by transportation can be offset
by speed of production and reduced financing costs for the project
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
56 | P a g e
Project management challenges
bull Difficulties in using automation in off-site production
In this survey based on literature reviews 4 main reasons for difficulties of using automation
in off-site production were selected to ask the participants Integration with advanced software and
high expenses of application in production line took approximately 60 of importance among others
Codding problem is another major problem in this subject which have 28 of pie chart In addition
company A demanded ldquoAn international coddingrdquo as a solution for this problem The last section
belongs to ldquolower salaries of manual processesrdquo which has the minimum importance of 14 among
participants
Figure 3 9 - challenges of using automation in off-site plants
bull Contracting problems
Starting with company A which acclaims that every state has its own code and the lack of a
universal code can bring challenges for modular players
Company B explained about the misunderstanding by final client who is the end home buyer
who ldquobelieves the factory to be the builder and the actual independent builder to be a sales agent
for the factoryrdquo Their recommended solution for this problem is to define the relationship between
the participants of projects their responsibilities by social media and requiring the builders customer
to sign a disclosure acknowledgement from that describes the relationship in detail
Company C mentioned a financial challenge caused by the banks in the projects that are
financed by them (Banks) which do not consider the project done until erected on-site This issue
creates pressure on cash flow of project where bank finance is involved The only problem that
company E consider in terms of contracts is lack of timing on project delivery which is generally causes
by constructors or general contractors
bull Lack of synchronization between projectrsquos participants
To begin with company A believes that there is a lack of quality partners on site They explain
that the problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution Company B mentioned that the responsibility of ensuring
28
29
29
14
Difficulties in using automation in off-site production
Codding Integration with advanced software Cost Lower salaries of manual processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
57 | P a g e
that the work is done properly belongs to the builder which any ldquodelays in this can result in postponed
transport of product and interest through demurrage charges
bull Sub-contractor for site planning and foundation phase
Company A uses local subcontractors for their site planning and foundation phases because
of variety of locations of their projects and ease of using local subcontractors Company B have only
the responsibility of modules production and defines the customer (the general
contractorindependent builder) responsibility to execute rest of the project phases have sub-
contractors if needed Company C does have sub-contractors for site-preparations and foundation
phases under direct supervision and the reason to not performing by their own is the high costs of
required equipment and not being portable for each project
bull Technology gap between sub-contractor and modular constructor
The only issue that were mentioned by participant is where company A recommended to ldquoto
educate most local subs on our process and reason for doing things a certain wayrdquo
Company B and C acclaimed that there are no challenges for the off-site production
Social challenges
bull Wrong perceptions among public and market
The only value that the market considers choosing modular method over traditional
construction is to be cheaper Company A says
According to company B experience in USA majority of people the media and even
professional engineers do not understand the capabilities of modular construction Many people
continue to confuse this form of construction with HUD on frame products
Another wrong perception that the publicmarket believes is that the prefabrication methods
limits the design options while Company C believe confirms that the reverse is the case
bull Solutions for resolving the wrong perceptions
Company A believes by using one of the main advantages of modular construction which is
shorter schedule the market can be dominated by modular projects and the more cases they deliver
the more recognised this method would be among the public and at the end the superior nature of
modular approach can be proved Company B addresses a solution in a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Company C acclaimed that advertising the modular advantages
among the public would be enough
Data analysis amp conclusions
The data from this survey can be used as an input data and prioritizations for the next chapter
which is decision-making process between four alternatives The solutions and recommendation will
be repeated at the recommendations at the final chapter as well Here are the conclusions about
advantages and challenges in modular construction mentioned by professional participants
Advantages
Economic benefits Generally apart from the other benefits as the participants mentioned
that there fewer number of workers are needed on and off site in comparison with traditional method
and Due to the shorter schedule of projects in modular projects can reduce the payments wages
Other fact that most of the participants are emphasizing is that the efficiency of work and added value
of activities off-site are much more than the on-site traditional projects
Environmental benefits Due to the variety of solutions for each material that they are using
in their modules there is high potential to send the used elements for recycling or would use into
mulch products A long lifetime span is acclaimed for the products which is close to the traditional
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
58 | P a g e
ones Majority of participants confirmed the literature concept that their products have the option to
integrate with other innovative technologies such as self-powered homes by solar panels and also
using advanced insulation technics made by non-petroleum materials in their panels to reduce the
energy consumption during operation phase In the waste management term there is a possibility for
production lines to generate significant amount of 70 less waste in comparison with traditional
method Moreover about carbon footprint reduction there is ability to reduce it 15 less that
traditional method by choosing environmentally friendly technologies in production and wise choice
of materials for products While there is argue that modular construction can achieve a 30 of energy
saving in comparison with traditional site-build method there are claims that their homes are not
positive from an energy perspective However this idea mentioned that by making a comparison
between off-site activities and on-site traditional construction due to the shorter schedules in off-site
production energy consumptions can be reduced up to 50
Social benefits As it was mentioned in literature reviews there are social benefits in modular
construction that can improve the satisfaction of clients Post-sale services for customers are possible
which is completely opposite to the traditional projectrsquos conditions
Challenges discussion
Initial costs It is obvious that a high amount of investment is needed to stablish an off-site
plant to start prefabrication of construction elements but the payback period is not that long that put
boundaries for start-up future players due to the collected information There are factors which can
make a change in initial costs of companies that are prioritized by the participants starting with
product types and production range level of automation which has direct relation with the initial
costs Off-site plantrsquos location the quantity of sub-contracted players in the projects and finally
financing and design enhancement have the minimum equal shares
Financial aids Financial assists which are crucial for kind of projects that are dependent to
these aids are not harmonized with modular project processes where there are argues that until the
first deliveries of elements to the site location and their assembly these aids are not reachable This
issue creates pressure on cash flow of project where bank finance is involved Changes in contract
conditions and education for financial supporters are recommended solutions to improve the
partnerships in projects
Design boundaries it was mentioned the subassemblies as the main element to be
considered in design phase while some players introduce a maximum dimension for their production
lines to be economically viable for transportation costs However there a possibility to eliminate the
boundaries for the designer by the production lines because by wise choice of prefabrication product
types
Lack of education The idea of lack of education among engineers and architects about off-
site construction methods was proved by the collected information which have to be resolved by
updating the education resources to innovative methods that can improve the productivity rates and
sustainability
Transportation regulations negative effects it is confirmed that the regulation by transport
administrative can be harmful for the projects such as extra costs or time delays on schedule Time
delays in giving permits to the manufacturers and constructors which can damage the synchronization
between production line and on-site installation by reducing the speed of transportation of elements
to the site A strategy to avoid this problem used legal load limits in their design instructions so that
their products will obey the regulations
Choice of transportable material effect In contrast with literature review which mentioned
the idea of extra costs by choices of transportable material this survey confirmed that the term of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
59 | P a g e
special transportable material will not add extra costs on the project Moreover the extra costs by
transportation can be offset by speed of production and reduced financing costs for the project
Automation use challenges Integration with advanced software and high expenses of
application in production line took approximately 60 of importance among others Codding problem
is another major problem in this subject In addition ldquoAn international coddingrdquo was mentioned as a
solution for this problem Every state has its own code and the lack of a universal code can bring
challenges for modular players ldquolower salaries of manual processesrdquo has the minimum importance
Defining responsibilities boundaries There is a misunderstanding by final client who is the
end home buyer who ldquobelieves the factory to be the builder and the actual independent builder to
be a sales agent for the factoryrdquo Their recommended solution for this problem is to define the
relationship between the participants of projects their responsibilities and requiring the builders
customer to sign a disclosure acknowledgement from that describes the relationship in detail
Lack of partnership among projectrsquos participants There is a lack of quality partners on site
The problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution The professionals answered that the responsibility of
ensuring that the work is done properly belongs to the builder which any ldquodelays in this can result in
postponed transport of product and interest through demurrage chargesrdquo
Wrong perception of publicmarket The only value that the market considers choosing
modular method over traditional construction is to be cheaper while majority of people the media
and even professional engineers do not understand the capabilities of modular construction Many
people continue to confuse this form of construction with HUD on frame products Another wrong
perception that the publicmarket believes is that the prefabrication methods limits the design
options while some players believe that the reverse is the case Therefore by using one of the main
advantages of modular construction which is shorter schedule the market can be dominated by
modular projects and the more cases they deliver the more recognised this method would be among
the public and at the end the superior nature of modular approach can be proved Another solution is
a form of cooperation between builders manufacturers architects and engineers to educate the
public by national entities such as Modular Home Builders Association
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
60 | P a g e
4 Decision making based on potential advantages among three
modular alternatives and conventional construction method in a
project by MIVES software Methodology
Objective
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria potential benefits can be recognised However to find out how much practical these benefits
are in the market several trade-offs must be done by professional tools such as project management
software programs which can take decisions based on the input data that receive
The objective of these thesis is to examine the practicality of modular construction by taking
the best decision among 4 alternatives including a conventional armed concrete building with steel
modular concrete modular and timber modular methods and see that the mentioned advantages can
lead the methods to become the best option to choose for building the project as a project
management point of view
What is MIVES
In order to make the most sustainable and reasonable decision among the alternatives a multi-
criteria decision-making program was used called ldquoMIVESrdquo MIVES is the acronym for Modelo
Integrado de Valor para una Evaluacioacuten Sostenible which means Integrated Value Model for a
Sustainable Assessment It is a multi-criteria methodology for decision making It allows transferring
the different characteristics of the objects to be evaluated to a series of homogeneous and
quantifiable parameters which facilitate the objectification of the choice
The MIVES methodology consists of creating a model that defines all the characteristic
features of the elements to be evaluated assigning them a function that allows converting the
different peculiarities of the alternatives into a common unit which we will call value Once the
amount of value for each alternative is obtained it can be used for a sustainable evaluation
(wwwdecaupcedu)
Data collection process
Case Study references
bull Journal of Cleaner Production (WAHammad 2019)
(httpsdoiorg101016jjclepro201904150)
This Fabolous multi-criteria comparison was done between two methods of conventional and
steel modular building in two cases case A which is a normal residential building and case B a school
building to measure the sustainability level of them in economic environmental and social areas The
location of this was considered in Sydney and central coast Australia and four BIM models had been
designed for each alternative in both cases The total floor area of Case A is 63 m2 (87m x 72m)
When adopting modular construction the granny flat is designed from 2 modules each module is
36m x 87m Case A was chosen as the study case to focus on because of type of the project that is
residential building
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
61 | P a g e
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study (WAHammad 2019)
The purpose of this journal is to add sustainability criteria as main factors for constructors to
make a multi-dimension decision whether to use Modular construction for a project or continue with
conventional methods
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and conventional methods
(Akbarnezhad 2019)
bull A comparative life cycle assessment (LCA) of concrete and steel-prefabricated
prefinished volumetric construction structures in Malaysia (Ali Tighnavard
Balasbaneh 2020)
(httpsdoiorg101007s11356-020-10141-3)
This researchrsquos focus is to compare two types of volumetric modules function in terms of cost
and LCA factors such as Greenhouse emission etc on a residential project with the approximate area
of 105m2 located in Malaysia based on local regulations Prefabricated Concrete Modules (PCM) and
Prefabricated Steel Modules (PSM) were considered for this project Recently Malaysian
administrative system has been pushing the companies and researchers to investigate on these types
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
62 | P a g e
of construction methods in order to measure the benefits and obstacles of using them in future project
and try to resolve the productivity problem in construction industry The construction industry in
Malaysia has been labelled ldquounproductiverdquo for its reliance on a large labour force and its use of non-
prefabricated strategies at a proper scale (Balasbaneh 2020)
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020)
bull Modular vs Conventional Construction A Multi-Criteria Framework Approach
published at ISARC 2017 (AWA Hammada and A Akbarnezhad 2017)
This paper did a comparative analysis in cost time and carbon emissions by BIM models
Material and equipment libraries and existent databases on a project in the North-West of Sydney
involves the construction of a granny flat with dimensions 14 m by 16 m
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017)
The framework of this papers based on the BIM model analysis with input data project actual
projectrsquos budget material and equipment used in the construction and environmental information in
database and then a comparative study on emissions during constructionmanufacturing schedule
and costs of project for crew material and equipment (Figure 45)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
63 | P a g e
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad 2017)
bull Life cycle greenhouse gas emissions and energy analysis of prefabricated reusable
building modules published on Energy and Building (Lu Aye 2011)
(httpsdoiorg101016jenbuild201111049)
Aye and his team did a LCA study on three alternatives PSM PCM and PTM which were used
in a multi-residential building with 63 apartment units with area of 63 m2
Figure 4 6 - Architectural section of multi-residential building (Aye 2011)
The modules in this study were categorized in 4 main elements Exterior walls with insulation
panels Interior walls used for internal separation which mostly build with timber frames and plaster
boards Floors with plywood material on topping in all alternatives and ceilings with thick plaster
boards and steel concrete and timber parts as main elements (Figure 47)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
64 | P a g e
Figure 4 7 - Structural elements used in modules (Aye 2011)
bull Comparing Environmental Impacts of Building Modular and Conventional Homes in
the United States published at Construction Matters (John Quale 2012)
(httpsdoiorg101111j1530-9290201100424x)
Quale did also a comparative analysis focused on Environmental emissions on two PTM and
Conventional Timber building Three residential modular companies generally representative of the
eastern US modular industry supplied data on completed projects for this study including utility
bills worker commuting information building materials and waste procedures construction
schedules employee schedules and other relevant information (Quale 2012) 186 m2 two-story
home that is a model for one of the companies involved in the study
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
65 | P a g e
Input data
4221 Alternatives
Four alternatives were selected for these study which are one conventional armed concrete
(Reinforced concrete RC) structure prefabricated steel modules (PSM) prefabricated concrete
modules (PCM) and prefabricated timber modules(PTM) that are most common solutions used by
contractors in the construction industry
4222 Requirement tree
These are groups of criteria which define a function to be evaluated A requirement usually
has several criteria Five requirements were selected based by literature review and the expertrsquos
opinions collected by survey among industrial players who were the participants of this questionnaire
Economic R1 time R2 environmental R3 safety R4 and social R5 requirements arranged in a way that
can examine the advantages adequately Time requirement were separated from economic one
because of importance due to high priority that have in the market to be chosen by the constructors
and clients In other words some clients and private builders choose the prefabrication methods such
as modular construction to save more time due to tight schedule that the project have Social and
safety requirements usually not being considered in sustainable decision-making processes but on this
study were included because the sustainability is not the only factor in project management
4223 Criteria
For each requirement a series of criteria are defined Criteria are the specific concepts that
the indicators contain the minimum unit to be quantified (wwwdecaupcedu) Each criterion was
chosen based on the importance among others efficiency on the project and availability of actual
amount and quantities in real cases over literature resources In other words the both advantages
and their functionality that modular construction have in comparison with traditional methods were
the main drivers to choose a criterion for each requirement as it mentioned earlier For economic
requirement cost of the project R1C1 was the only criteria that was considered which in the literatures
is expected to save 20 by choosing modular method in final cost (McKinsey amp Company 2019) while
experts in survey believe that the cost of transportation of prefabricated elements to the site can
compensate the difference with traditional method To examine these two opinions these criteria was
chosen In Time section the projectrsquos schedule R2C1 was only criteria to measure the important
advantage that the modular construction has Both literatures and expert agreed the time saving that
modular approach can bring to the project which is about 50
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES)
R1 - Economic
R1C1 - Project cost
R2 - Time
R2C1 - Project schedule
R3 - Environmental
R3C1 - Energy consumption
R3C2 - Waste generation
R3C3 - Material consumption
R3C4 - Noise Polution
R3C5 - Greenhouse gas emission
R3C6 - Recycle
R3C7 - Embodied energy
R4 - Saftey
R4C1 - Injury risks
R4C2 - Protection from natural cuases
R5 - Social
R5C1 - Job status
R5C2 - Quality
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
66 | P a g e
Seven criteria were chosen to cover the environmental requirements for this decision-making
process based on the available data in literatures However in this section not only advantages of
modular methods were considered but in some areas conventional reinforced concrete showed
better results and this fact can improve the liability and practicality of final decision For instance the
embodied energy of steel modular building is 30 more than the conventional during the construction
but the saving caused by re-useability of element in modular method can almost compensate the gap
between these two methods Energy consumption R3C1 which is the energy consumed during the
constructionfabrication amount of Waste generated R3C2 in all alternatives Material consumption
R3C3 in each method Noise pollution R3C4 Greenhouse gas emission R3C5 Recycle of elements R3C6
and Embodied energy for each method were chosen in this section
Safety issue as it has mentioned before was added to decide further than sustainability
concept boundaries which include two criteria Injury risk for workers R4C1 and Protection of project
from nature causes R4C2
Finally Social benefits which are not as main factors to be considered by construction players
to use the modular methods but are important enough to pay attention and were compared as well
by two criteria Job status R5C1 and Quality R5C2
4224 Indicators
The indicators for this study came directly from scientific articles which most of them were
published few months ago and it can be said that the data which were used for this study is updated
with the latest achievements in modular construction industry
To begin with for economic measurements two indicators for the project cost were selected
total project cost R1C1I1 and costs stability R1C1R2 Total project cost R1C1I1 for conventional RC
alternative means the final cost of construction including all the activities until the delivery of building
In modular alternatives PSM PCM and PTM includes the module fabrication in off-site plants
transportation installation on-site and final finishing of building after the assembly phase All
indicators are based on ldquoAustralian dollarsrdquo units (AUSD) because of the recourse quantities that was
used for this study which will be discussed more later Second indicator which is the costs stability
(R1C1R2) was chosen because of the common off-site production economic advantage that is
stabilizing the costs for the projectrsquos budget because of high quality of product more repetition of
elements and more accurate supervision on activities which leads to less reworks and less extra costs
etc
Total project schedule R2C1I1 is the first indicator for time requirement which include the
amount of time to fabricate transport and final assembly of the modules on-site in modular
alternatives and the final schedule of the conventional project during construction activities until the
delivery of the building which all are based on ldquodaysrdquo it was mentioned earlier that in off-site
production the project schedule can be estimated and controlled more adequately so that second
indicator which is time stability R2C1I2 was introduced to the study
Environmental requirement was studied in various features as it said before in 7 criteria which
shows the complexity of comparisons between alternatives First indicator is the Energy utilized during
construction R3C1I1 based on ldquoMJrdquo units Solid Waste R3C2I1 is the only indicator for Waste
generation criteria that focuses on the amount () of waste which was produced during
constructionfabrication activities in all four activities In material consumption criteria the total
amount of materials that was used for constructionfabrication of elements R3C3I1 is appointed as an
indicator to compare the benefits in each alternative based on ldquoKgrdquo Noise reduction in off-site
construction is another benefit that it has and to discuss this fact among the alternatives Average A-
weighted equivalent sound level of each construction equipment R3C4I1 based on ldquodBrdquo units was
focused on Greenhouse gas emission among alternatives was measured in CO2 that was produced
during constructionfabrication activities R3C5I1 based on ldquoKGrdquo units Two indicators were introduced
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
67 | P a g e
for recycle criteria between four alternatives recyclability or possibility of recycling of elements
R3C6I1 and Re-use of elements (Products) in projects R3C6I2 based on Percentages Embodied energy
was the last criteria which was focused on with two indicators Embodied energy used R3C7I1 in ldquoGjrdquo
units and Embodied energy saved by re-use of elements in percentages among alternatives
For safety measurements two indicators were selected for two criteria which are injury risk
level R4C1I1 for injury risk criteria and Protection level R4C2I1 for protection from nature causes both
in a qualitative unit
Job stability R5C1I1 for comparing the job status in terms of security of jobs among two
methods and new job creation R5C1I2 to analyse the possibility of providing new job positions which
is crucial in these era in construction industry were chosen in qualitative unit
The last criteria in social requirement which is quality of projects was presented with one
indicator of quality satisfaction of client R5C2I1 in qualitative unit to compare the clientrsquos satisfaction
level between alternatives Table 4 1 - Requirement tree with all indicators which considered for decision making process
Requirements Criteria Indicators
(R1) Economic (R1C1) Project Cost (R1C1I1) Total Project Cost
(R1C1I2) Cost Stability
(R2) Time (R2C1) Project schedule (R2C1I1) Total Project Schedule
(R2C1I2) Time Stability
(R3) Environmental
(R3C1) Energy Consumption (R3C1I1) Energy Utilized during construction
(R3C2) Waste Generation (R3C2I1) Solid Waste
(R3C3) Material Consumption (R3C3I1) Material Consumed in project
(R3C4) Noise Pollution (R3C4I1) Average A-weighted Equivalent sound Level of each instrument
(R3C5) Greenhouse Gas Emission (R3C5I1) Co2 in constructionfabrication
(R3C6) Recycle (R3C6I1) Recyclability of Elements
(R3C6I2) Re-use of elements
(R3C7) Embodied Energy (R3C7I1) Embodied Energy Used
(R3C7I2) Embodied Energy Saved
(R4) Safety (R4C1) Injury Risks (R4C1I1) Injury Risk Level
(R4C2) Protection from Nature Causes (R4C2I1) Protection Level
(R5) Social (R5C1) Job Status
(R5C1I1) Job Stability
(R5C1I2) New Job Creation
(R5C2) Quality (R5C2I1) Quality Satisfaction of Client
The input data for indicators are categorized in 4 types direct data calculated data estimated
data and qualitative data The reason for not having only direct data is the lack of enough literature
researches on this subject and in some cases the data were published two months before the date of
this study The variety of alternatives which is the first time that a study is going to analyse 3 modular
alternatives and a traditional method added difficulty to find useful data to do the decision making
reliable Moreover 5 articles were used for finding the correct data which each of them focused on
different alternatives The orientation of this study is the Cleaner Production journal by professor
Hammad that was published in 2019 which was mentioned earlier The reason of this orientation is
that most of the data came from this article and is more updated than the others
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
68 | P a g e
bull Direct Data
The direct data were the information that was related precisely to the alternatives without
any needs to change For instance the cost of the construction in Hammadrsquos article which can be used
without any changes The green parts on the Table 42 shows the direct data which are related to the
Hammadrsquos article Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed to be done on them
bull Calculated Data
In many indicators because of lack of existence in directly related data for alternatives a sort
of calculations were needed to change the data from other articles that related to alternatives that
are not focused in main case (Hammadrsquos article) to actual data based on the area of main article by
using accurate coefficients and ratios For instance in Hammadrsquos article CO2 was not estimated for
Prefabricated Steel Modules (PSM) alternative but Ayersquos CO2 data which is for total area of 3943m2
with 63 apartments each area of 628 m2 (close to 625 m2 area of Hammadrsquos granny flat) was used
by dividing on 63 apartments units so that results 54079 kg of CO2 for steel modular equivalent for
main case The yellow parts show the calculated data for indicators
3407000119896119892 1198881199002 divide 63 119906119899119894119905119904 (6251198982) = 54079119896119892 1198881199002 for steel modules in main case
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other studied
bull Estimated Data
Third type of input data were the necessary data which are not existed on any of literatures
of have to be estimated based on the qualitative information professional survey which have been
done before the decision making process (Chapter 3) and researcherrsquos opinions Fortunately in many
areas the data could be applied on other alternatives because of similarity of activities off-site and
onsite For instance for PCM alternative the noise and Injury risk level are approximately the same
the indicators of PSM case that have mentioned in Hammadrsquos article which are shown in green parts
in Table 42 because of similarity of off and on site activities during construction
The blue parts are the estimated data that were considered for PCM alternative based on
mentioned resources For instance the time indicator can be predicted 24 days few days more the
steel modules which is around 22 days because of the fact that concrete modules are heavier than
steel ones and has more complexity in structure for being produced that adds difficulties on
transportation process which leads to more delays on the schedule Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow)
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
69 | P a g e
bull Qualitative Data
This data was added because of two reasons first the lack of existence of direct data on
literatures and improve the literatures background on this subject and secondly to have more
influence from variety of benefits that modular construction has on the decision making process
Numbers of literatures insisted on advantages that can affect the decision making but did not
included on their data analyses at the end and this research decided to include these data and see
that how much functional can be in the decision making between alternatives in point of project
management view For instance cost stability which is better coordinated in off-site construction and
can be considered as an advantage to the decision making is not included in the literatures during
analysis and in this study is a vital factor for the economic criteria In order to add this indicator a
qualitative range was considered from 0 to 10 and four alternatives based on their functionality in cost
stability in project budget were compared to each other Traditional reinforced concrete building
which because of common reworks etc have less stability in final budget estimation On the other
side PSM and PTM which have the most repetition in manufacturing processes and ease of production
because of material type have the maximum cost stability of 9 out 10 among the others and PCM that
has less ease in production have less cost stability than other modular alternatives with 8 out of 10 Table 4 5 - Qualitative indicators
Final indicators
bull Prefabricated Steel Modules indicators (PSM)
As it mentioned before the direct data which are shown in green at table 46 do not need any
changes as they belong to the main case study while other indicators are still needed to be calculated
estimated and often considered qualitatively Aye case study have the closest data to the main case
study because of similarity of project type and dimensions so that the necessary indicators such as
material consumption waste generation percentage re-use amount and embodied energy indicators
can be calculated from this analytical study (For more information about indicators resources please
see Annex 1-A) Table 4 6 - First hand data over literature
A simple calculation is needed and that is dividing the CO2 emission Material
consumption and Embodied energy used amounts in Aye project on 63 apartment units with the
same area of 625 as main case in Hammads residential flat ldquoWaste amountrdquo ldquore-use of elementsrdquo
and ldquoembodied energy savedrdquo can be applied on the main case because of similarity of material
choices
IndicatorsAltertanives TRC PSM PCM PTM
Cost stability 6 9 8 9
Time stability 6 9 8 9
Recycleability of elements 3 8 7 9
Protection level 2 9 9 9
Job stability 5 8 8 8
New job creation 3 8 8 8
Quality satisfaction 5 9 8 9
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
70 | P a g e
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow)
bull Prefabricated Timber Modules indictors (PTM)
As it can be seen in table 48 there are no enough data over literature in many areas and due
to the necessities for this study a range of calculations and estimation have to be made based on the
similarity of projects among study cases and survey information Table 4 8 - First hand data over literature
Starting with Cost of the project which an ldquoestimationrdquo based on literature review information
and qualitative comparisons (John quale 2012) (Lu Aye2011) that is approximately 45000 AUD
because it proved that the cost of Timer modules is even cheaper than Steel Modules due to simplicity
of material choice and structure design The schedule of PTM building is shorter than the other
alternative because of numbers of reasons such as less weight of elements which can lead to faster
transportation loading and offload in assembly process on-site In addition the manufacturing lines
are simpler than other modular alternatives because of high repetitions and simplicity in design
For ldquocarbon emissionrdquo and ldquomaterial consumptionrdquo Aye project was used by diving on 63
apartment units which have the same area of 625 m2 as main case In terms of ldquowaste generationrdquo a
unique article was used (by Doyoon 2008) which did a LCA study on Timber modular building and the
amount of wastematerial consumed was about 9 The Noise level and Injury risk can be applied
from other modular alternative because of similarity of construction activities and equipment used
for fabrication Energy utilized during construction of Timer modules have the minimum amount in
comparison with other alternatives because of simplicity of material choice and design enhancement
so that was estimated 80MJ which is slightly less than steel modules with 86 MJ
Re-use of elements in timber modular elements was confirmed by survey among the
constructors over than 70 with a life span of 50 years Embodied Energy used was collected from
Aye case study dividing on 63 apartments units as same as other cases which equals to 65671 GJ
(Table 49) Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue)
bull Prefabricated Concrete Modules indicators (PCM)
The least focus on modular alternative was on Concrete Modules which is because of few uses
that this method has among the projects Balasbaneh study focused on a comparison between Steel
modules and Concrete modules in total project cost and LCA Table 4 10 - First hand data over literature
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury risk Energy utilized Re-use Embodied energy Emb saved
Aye 2500000 996 356 41373 691
Quale 13600
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 45000 20 39375 1580952 9 645 163 80 70 65671 691
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Balasbaneh 239380 8264
Units MLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
71 | P a g e
However the currency of this economic analysis is not as AUD (Australian Dollars) as the main
study Therefore to calculate the cost and CO2 footprint corresponding to main study case a ratio
was obtained between concrete modules amounts and steel modules in Balasbaneh study and then
multiplied to the steel modules quantities in Hammadrsquos main case and resulted project cost of
5188603 AUD and 46442 kg of CO2 emissions
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM alternatives
239380 divide 222580 = 1075478 119862119900119904119905 119903119886119905119894119900 (Balasbaneh study case)
482446 times 1075478 = 5188603 119860119880119863 Total project cost of PCM
8264 divide 9623 = 085877 1198621198742 119903119886119905119894119900
54079 times 085877 = 46442 119896119892 CO2 of PCM
The time indicator was estimated based on steel modules but with this difference that
concrete modules weight more than steel ones so that puts pressure on the transportation and
assembly phases and causes delays in the schedule as a result 24 days was predicted to finish the
project
There is no available information on the literature with specific quantitative details however
based on the qualitative structural information prefabricated concrete modules PCM because of their
similarity of material choice to conventional model have a massive material use in comparison with
Steel and Timber alternatives so that an estimated total material consumed of 20000kg assigned for
this indicator (Aye 2011) (Balasbaneh 2020)
Waste generation have a higher ratio in this alternative because of material choices which
generate more waste than other modular alternatives With this fact in mind the waste ratio
considered slightly more than steel kind with 10 (Aye 2011)
Noise level and Injury risk can be applied from other types because of similarity of equipment
and construction activities in all three modular alternatives (Hammad 2019)
Energy utilized during construction in PCM Alternative can be estimated more than steel ones
because of types of materials used in these modules and their high weight with value of 90MJ (Aye
2011)
The structural elements are ldquonotrdquo built in material which have a high recyclability potential so
that decreases the Re-use ratio to 20 approximately in comparison with other modular alternatives
(Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
72 | P a g e
Embodied energy used amount and its potential saving have the minimum value in a
qualitative comparison with other alternatives which respectively values of 800GJ and 60 were
estimated for them (Aye 2011) Table 4 11 - Final indicators for PCM
bull Traditional Reinforced Concrete (TRC) final indicators
The highest focus over the literature is to make a comparison between one of the modular
options and a traditional method which results more availability for direct data for Traditional method
The main case study is not an exception with almost half of the value are available directly such as
Project cost Time Noise level Injury risk and Energy utilized during construction which are shown in
green at table 412 (Hammad 2019) Table 4 12 - TRC first-hand data over literatures
Nevertheless still there are values that must be calculated over literature Green gas emission
indicator and Embodied Energy used were calculated form Ayersquos case study by dividing the values on
63 apartment units which results 3620635kg Co2 emission and 6033 GJ of 625 m2 area as same as
main case study (Aye 2011) (Hammad 2019)
Material consumption have the same methodology as carbon footprint with final value of
626825kg which is massively higher from modular alternatives (Aye 2011) (Hammad 2019)
Waste generation was calculated qualitatively from a literature resource called ldquoModular
Construction for Multifamily Affordable Housingrdquo by WSP which acclaims that the conventional site-
built method produces around 25 times more construction waste (WSP 2018) Thus TRC waste
generation is more than 25 times of modular ones with the value of 15
Two values of Re-use and Embodied energy saved by Re-use of elements were obtained from
Ayersquos case study respectively 22 and 322 (Aye 2011) Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow)
In general the table 414 shows the References and final indicator values that were used for decision
making process (Direct data are shown in Green Calculated data in yellow and estimated data in
blue)
Table 4 14 - Final Quantitative indicators used for decision making process
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 812298 6598 71 217 198
Akbarnejad 120000 67 84672
Aye 2281000 3949 22 38008 322
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
PSM 482446 2131 54079 138254 5 645 163 8593 50 9012 813
PTM 45000 20 39375 1580952 9 645 163 80 70 65671 691
PCM 5188603 24 46442 20000 10 645 163 90 20 800 60
TRC 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrence Ham Aye Balas Hammad Balas Aye Aye Doyoon WSP Aye Hammad Hammad Hammad Aye Aye Aye
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
73 | P a g e
Weights
The Weights (Pesos in MIVES) which are one of the most important factors in decision making
process have be assigned on the data in a way that the priority of each section in terms of efficiency
and importance can decide which value will have among the others AHP method was used to assign
weights on the data In AHP you get the weights through the subjective importance of each element
with respect to the others (Alejandro Josa 2012)
bull Weights of requirments
The importance of requirmenets was assumed based on proffessional survey among
constructors architects sales agents and clients in order to know the demands of market and make
the decision rely on what market expects from a innovative method According to the survey time
reduction is the first priority for choosing the modular methods by constructors and future clients so
than acheived 30 of weight Economic issues came after the time factor because of unconsistency
between responds about cost saving on the budget or offseting the expenses gap by tarnsportation
extra costs on the project Economic requirement has 27 of weight In some regions the priority of
choosing an innovative method are environmental emissions waste generation and recycleability of
products Therefore environmental requirement came after the economic one with 25 of weight
As it mentioned before Social and safety advantages are included in this decision making
process with respectly weights of 13 and 5 because of their less priorities among clients and market
players Table 4 15 - Requirement weights
Requirement Economic Time Environmental Safety Social
Weights 27 30 25 13 5
bull Weights of criteria
In cost and time of project which are single criteria have 100 of weights However for
instance in environmental and AHP method must be used to assign the weights based on the
importance in an environmental consideration The amount of emission that construction activities
can produce and the amount of negative effect on the global environment have been considered for
AHP method in weight assignment process Energy consumption and material consumption have the
priority to consider in LFA analysis because the consumption of primary resources have to be
minimized in a project at the first step and then the emission have to be reduced by changing the
processes etc Finally the ability to re-use and recycle and elements must be improved (Mohammad
Kamali 2017) (John Quale 2012) (Marta Gangolells 2014) Therefore Energy Consumption and
Material consumption have the most weight of 17 Embodied energy with 16 and waste generation
Greenhouse Gas emission and Recycle achieved 15 of weight At last noise Pollution took the least
priority of weights with 5 Table 4 16 - Weights of criteria
bull Weights of Indicators
Both of Economic and Time indicators divided to two sub-categories project cost and time and
their stability ratios with 80 and 20 weights by AHP method
Criteria that are single indicator obviously have 100 of weights However there are two
indicators in recycle criteria Recyclability and Re-use of elements with 40 and 60 weight
respectively Moreover Embodied Energy have is divided to Embodied energy used which is more
CriteriaEnergy
consumption
Waste
generation
Material
Consumption
Noise
pollution
Greenhouse
gas emissionRecycle
Embodied
energy
Weights 17 15 17 5 15 15 16
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
74 | P a g e
important than the other that is saving in embodied energy by re-use because as it mentioned before
in the first place the use have to be minimized and then actions such as re-use of elements have to be
done 70 of weight for Embodied energy use and 30 for Saved Embodied energy are assigned Job
stability and New job creation with weights of 50 each are the Job status indicators (Figure 411)
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software
Value function play an important role on deciding which comparative final value can each
indicator have among the other indicators for each alternative To evaluate the sustainability index
(Is) of each alternative solution value functions assigned and were used (Alarcon et al 2011) The
generic form of a value function is represented by Table 417 which allows to assess the sustainability
(satisfaction) associated with each indicator by transforming the physical units to a dimensionless
value between 00 and 10
Equation 4 1 - Functionality of value function elements
In Eq (41) B is the value of indicator(Iind) for Xmin Xmin is the minimum abscissa value in the
indicator interval assessed X is the abscissa value for the indicator assessed Pi is a shape factor which
defines whether the curve is concave (Pi lt 1) convex (Pi gt 1) linear (Pi = 1) or S-shaped (Pi gt 1) (see
figure 412) Ci approximates the abscissa at the inflexion point Ki tends towards (Iind) at the inflexion
point B the factor that prevents the function from exceeding the range (0 1) is obtained by Eq (42)
Xmax being the abscissa value of the indicator that gives a response value of 1 for increasing value
functions
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
75 | P a g e
Equation 4 2 - B value equation
Figure 4 12 - Possible forms of the value function
Due to the lack of existence of resources for assigning the specific value functions for modular
alternatives some hypotheses that can increase the feasibility and sustainability of project were
considered for the shape P K and C values to select the best form of abacus
In the other side maximum and minimum satisfaction points were selected on the
expectations of a project management view For instance in total project cost indicator case
minimum satisfaction point is 82000 AUD that is slightly more than the traditional reinforced concrete
alternative project cost (812298 AUD) because of the fact that those alternatives should be
considered as a reasonable options which can make saving in final budget Moreover the same rule
can be applied for maximum satisfaction point which is close to the Timber Modular alternative (45000
AUD) to minimize the final budget as much as possible The shape of the abacus was selected as
Convex shape (Convexa in MIVES) because even the least economic saving that an alternative can
achieve have a positive effect on the satisfaction of project and can be given any positive points in a
scale of ldquo0 to 10rdquo But the more the curve closes to the traditional alternative budget the les
satisfaction it can receive (Figure 413)
Figure 4 13 - Value function for total project cost in MIVES
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
76 | P a g e
The following Table 417 includes the value functions which were used for the rest of the
indicators Table 4 17 - Value function for indicators in MIVES
Data analysis
Indicators Values
Indicator data were translated to general normalized values shown in Table 418 amp 419 based
on the given value functions that earlier assigned This step is crucial for next analyses which will be
done to result the criteria and requirement values which lead to sustainability Indexes that can take
the multi-criteria decision As it can be seen these values have the same range of 0 to 1 so that can be
compared in with a common unit Comparisons are obvious in this level because of single value
orientation of each indicator however on following analysis there will be multi-criteria comparisons
which can achieve useful data for future decision-making process Table 4 18 - Indicators normalized values
Table 4 19 ndash Indicator normalized values
Indicators Lower limit Upper limit Max satisfaction Min satisfaction P K C Shape
Total Project Cost 30000 90000 43000 82000 05 05 79900 Concave
Cost stability 0 10 10 5 05 05 55 Concave
Total Project Time 20 75 20 68 05 05 632 Concave
Time stability 0 10 10 5 05 05 55 Concave
Energy Utilized 75 220 80 205 05 05 1925 Concave
Solid Waste 0 100 0 18 08 05 162 Concave
Material Consum 10000 70000 12000 63000 05 05 57900 Concave
Noise Level 58 78 62 72 05 05 71 Concave
CO2 32000 60000 32000 55000 05 05 52700 Concave
Recyclability 0 10 10 0 05 05 1 Concave
Re-use 0 100 60 0 05 05 20 Concave
Embodied energy 600 950 600 915 05 05 8835 Concave
Embodied saved 0 100 90 30 05 05 36 Concave
Injury risk 0 4 155 22 05 05 2135 Concave
Protection level 0 10 10 0 1 001 1 Lineal
Job stability 0 10 9 4 1 001 45 Lineal
New job creation 0 10 10 0 05 05 5 Concave
Quality Satisfaction 0 10 10 0 1 001 5 Lineal
R1C1I1 R1C1I2 R2C1I1 R2C1I2 R3C1I1 R3C2I1 R3C3I1 R3C4I1 R3C5I1
TRC 016 051 024 051 027 029 01 034 092
PSM 094 092 098 092 098 082 099 088 023
PCM 09 081 097 081 097 059 093 088 065
PTM 098 092 1 092 1 064 097 088 085
R3C6I1 R3C6I2 R3C7I1 R3C7I2 R4C1I1 R4C2I1 R5C1I1 R5C1I2 R5C2I1
TRC 073 026 1 024 024 021 02 063 05
PSM 095 094 023 095 094 09 08 092 09
PCM 092 068 064 077 094 09 08 092 08
PTM 098 084 092 085 094 09 08 092 09
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
77 | P a g e
Criteria Values
MIVES analysed each criterion by single or multi-indicator normalized values and resulted
values with a same range of 0 to 1 for following comparisons Table 4 20 - Criteria normalized values
Table 4 21 - Criteria normalized values
To begin with Project Cost (R1C1) criteria values shows that Almost three modular
alternatives performed 3 times more than the traditional method positively caused by hugely less total
project cost (R1C1I1) and great cost stability (R1C1I2) in project final budget The minimum value
belongs to PTM with 097 and slightly more than PSM and PCM is the next alternative with a value of
088 and at last TRC with 023 (Figure 414)
Figure 4 14 - Criteria normalized values
The comparison between modular alternatives in terms of which one can save time on the
schedule is close and it can be said that all three can make the project executed more than 3 times
shorter than traditional approach Timber steel and concrete options with respectively 098 097 and
094 values were compared to the conventional concrete method with 029 value (Figure 415)
R1C1 R2C1 R3C1 R3C2 R3C3 R3C4
TRC 023 029 028 029 009 032
PSM 094 097 099 083 099 088
PCM 088 094 096 059 094 088
PTM 097 098 101 064 096 088
R3C5 R3C6 R3C7 R4C1 R4C2 R5C1 R5C2
TRC 091 045 083 024 021 040 052
PSM 024 096 048 095 090 088 092
PCM 064 077 072 095 090 088 080
PTM 085 091 096 095 090 088 092
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
78 | P a g e
Figure 4 15 - Project Schedule
ldquoEnergy saving potentialrdquo in modular methods are close to the maximum satisfaction point
with timber solution and steel modules while concrete option is on the chase with 096 While
Traditional alternative only have 28 of satisfaction level
ldquoWaste generationrdquo among the alternatives have a different attitude while traditional method
with value of 029 has the most ratio of material waste production modular alternatives are
performing better where steel option have the most reduction with value of 083 and follow to that
timber and concrete options respectively 064 and 054 values PCM alternative as it said before
because of similarity of material choice to TRC have the minimum performance among the other
three (Figure 416)
Figure 4 16 - Waste generation ratios
ldquoMaterial consumptionrdquo criteria are dominated by modular methods which have a high
satisfaction with over than 09 normalized values while TRC performance can be concerning for the
primary resources with 01 normalized value
Previously on this report the fact was mentioned that off-site construction can benefit the
environment with noise reduction during construction activities based on literatures and this study
confirms this advantage by 088 values of all three modular alternatives and 032 value of traditional
RC which is less than half of modular options
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
79 | P a g e
A highlight of this study is about the comparison of CO2 Emissions of alternatives during the
constructionfabrication activities which traditional method have the minimum contamination with a
value of 091 and follow to that Timber option with 085 which is close to the TRC method Later to
that Concrete modules have a value of 064 and the minimum satisfaction belongs to the steel
modules with 024 normalized value This result bring uncertainty to the fact that modular
construction can reduce the Greenhouse gas emission to 30 over the literature review
Figure 4 17 - CO2 Emission normalized values
This study shows that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options with a value of 096 because of the material choice
repetition in element manufacturing and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution have 091 value that can confirm the concept of
recyclability for wooden modules which was mentioned by participants in professional survey as well
Figure 4 18 - Recyclability and re-use potential of alternatives
There is a discussion about the amount of embodied energy used during the lifetime of each
alternative and the potential of future saving by re-use of elements in projects which effect the total
embodied energy consumption in construction
As the Figure 419 explains traditional method has the maximum satisfaction level in terms
of consumption while steel modules have the least satisfaction of life cycle embodied energy used of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
80 | P a g e
023 PTM have a better value of 091 which shows that Timber solution can be reliable among the
others
However this study resulted that the most re-use value belongs to steel option with 095
value that and other two timber and concrete modules respectively with 085 and 077 can
compensate the gap with traditional method that has only 024 Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction total value of 096 Later
traditional reinforced concrete method with 088 still proves its abilities over other two modular
alternatives
Figure 4 19 - Embodied energy consumption and saving potential by reuse
In terms of safety modular alternatives because of their off-site nature can provide a high
satisfaction level with values of 095 in injury risks for workers and 090 protection from nature causes
which confirms the theory of safety advantage of modular construction over traditional methods from
literature studies (Figure 420)
Figure 4 20 - Safety advantage of modular construction over traditional method
Social benefits which were mentioned in literature review section also had been examined in MIVES
system and the job stability and job creation in modular construction can benefits the construction
society in significant way among the regions that have employability ratio problem
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
81 | P a g e
Figure 4 21 - Social criteria
Requirement Values
After analysis on criteria functions general values of each requirement were related to
alternatives achieved which can examinate all four construction methods to know which option is
more suitable in terms of Economic time environmental safety and social issues
The Table 422 below demonstrates the Requirements normalized values for each alternative Table 4 22 - Requirement normalized values for four indicators
bull Economic and Time requirements
As the graph illustrates Modular methods have a significant performance in economic and
time terms with the maximum values of 097 and 094 in Time and 098 and o97 in Economic
requirement for Timber and then Steel modules-based methods respectively Traditional reinforced
concrete option showed a poor functionality in cost and time of project with minimum values of o29
and 023 in order (Figure 422)
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values analysed by MIVES
Requirements Economic Time Environmental Safety Social
TRC 023 029 045 022 046
PSM 094 097 075 093 088
PCM 088 094 078 093 084
PTM 097 098 088 093 088
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
82 | P a g e
bull Environmental requirement
Generally all three modular approaches have beaten the traditional method with almost
double of normalized values in comparison
Despite the poor performance of steel modules in Greenhouse gas emissions and Embodied
Energy used in construction in total numbers proved that can provide the environmental demands
better than traditional option with a value of 075 which is third modular alternative in overall
Prefabricated Timber modules obtained the maximum value of 088 which claims not only
most economic option but environmentally friendly among other relatives and following to that
Concrete modules with value of 078 shows its liability to be chosen in case of need while the
traditional concrete method which includes most of the used materials n PCM but in a on-site plant
only can achieve a satisfaction value of 045 among the others (Figure 423)
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind
bull Safety and social requirements
The dominance of Modular construction in safety and social requirements over conventional
option can be seen in Figure 424 which can raise the possibility of modular methods to be the best
decision over the traditional option to construct this residential project As it was mentioned before
these two criteria must be considered in any decision-making process because of their high
importance in construction industry
Figure 4 24 - Modular dominance in safety and social requirements over conventional option
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
83 | P a g e
Sustainability Values (Final decision)
Finally the sustainability Indexes can be obtained to claim which alternative will be decided
as the most sustainable option for the main studyrsquos project to be build The needs of market such as
short project schedule cheaper budget reduction in environment emissions and ability to
recyclereuse safety measures and social benefits put effects on this decision as previously
mentioned
Table 423 explains that Prefabricated Timber Modules (PTM) is most sustainable alternative
among the other with a perfect normalized value of 094This could be because of its shorter schedule
of construction lowest total budget and excellency in environmental performance among the other
alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative Table 4 23 - SI (Sustainability Indexes related to four alternatives)
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This fact explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives
TRC PSM PCM PTM
SI 032 090 088 094
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
84 | P a g e
5 Conclusions Decision making process
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria etc However to find out how much practical these benefits are in the market several trade-
offs must be done by professional tools such as project management software programs which can
take decisions based on the input data that receive MIVES software was used in this study to
examinate these benefits The resources for this type of studies are limited due to the lack of focus or
newfound nature of this subject and only five of them were selected because of their variety of their
criterion studies reliability and accuracy of data Requirements criteria indicators and weights that
were used in MIVES had been selected based on demands of market and professional opinions
received from the survey and availability of data over references After assigning the value functions
which are related to satisfaction level on each criterion (For instance cost reduction time saving and
minimization of emissions) normalized values were achieved that can be compared between
alternatives with range of 0 to 1
Conclusions and discussion
ECONOMIC ndash TIME discussion
bull Decision-making result
Generally all three modular alternatives have beaten the traditional method with almost
double of normalized values Modular methods had a significant performance in economic and time
terms with the maximum values in Time and Economic requirements for Timber and then Steel
modules Traditional reinforced concrete option showed a poor functionality in cost and time of
project with minimum values
Literature reviews information
These Results confirm the 50 of time saving in projectrsquos schedule (McKinsey amp Company
report 2019) and 20 of cost reduction on the budget which was mentioned also in numbers of
literatures
Professional survey confirmation
In addition the claims from professional participants in survey about the 50 cost reduction
due to the added value of every hour of work in comparison with traditional stick and build on-site
method can be approved even far more those expectations
ENVIRONMENTAL discussion
bull Recyclability and re-use potential
This study showed that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options because of the material choice repetition of
elements in manufacturing line and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution can confirm the concept of recyclability for wooden
modules which was mentioned by participants in professional survey as well
bull Embodied energy used and saving by re-use
There is a discussion over the literature and survey participants about the amount of
embodied energy used during the lifetime of each alternative and the potential of future saving by re-
use of elements in projects which effect the total embodied energy consumption in construction
where one of the companies acclaims that ldquoour homes are not positive in energy consumption
aspectrdquo Traditional method has the maximum satisfaction level in terms of consumption while steel
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
85 | P a g e
modules have the least satisfaction of life cycle embodied energy used PTM have a better value of
091 which shows that Timber solution can be reliable among the others However this study resulted
that the most re-use value belongs to steel option and other two timber and concrete modules
respectively can compensate the gap with traditional method Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction Later traditional reinforced
concrete method still proves its abilities over other two modular alternatives
bull Greenhouse gas emission
Despite the poor performance of steel modules (PSM) in Greenhouse gas emissions that bring
uncertainty to the fact that modular construction can reduce the Greenhouse gas emission to 30
over the literature review and Embodied Energy used in construction proved that can provide the
environmental demands better than traditional option which is third modular alternative in overall
comparison
bull Most environmentally friendly alternative
Prefabricated Timber modules obtained the maximum value which achieves not only most
economic option but environmentally friendly among other relatives Following to that Concrete
modules shows its liability to be chosen in case of need while the traditional concrete method which
includes most of the used materials of PCM but in an on-site plant only can achieve the minimum
value
Comparison with literature review information and survey outputs
This comparison explains the truth about the concept of being environmentally friendly about
modular construction that have been mentioned in various scientific articles (McKinsey amp Company
report 2019) (M Kamali 2016) and the survey results which confirmed the concept in real cases at
the market over years of experience
SAFETY AND SOCIAL dominance by modular methods
The dominance of Modular construction in safety and social requirements over conventional
option was resulted which can raise the possibility of modular methods to be the best decision over
the traditional option to construct this residential project As it was mentioned before these two
criteria must be considered in any decision-making process because of their high importance in
construction industry Social benefits which were mentioned in literature review section also had been
examined in MIVES system and the job stability and job creation in modular construction can benefits
the construction society in significant way among the regions that have employability ratio problem
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES
Prefabricated Timber Modules (PTM) is most sustainable alternative among the other with a
perfect normalized value of 094This could be because of its shorter schedule of construction lowest
total budget and excellency in environmental performance among the other alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This result explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
86 | P a g e
Effective external factors on decision
The decision was made for the best alternative in terms of sustainability for a specific
residential case located in Sydney Australia among three modular options and one traditional
method However there are factors which can affect the final decision obviously Such as the location
of the project which the availability of primary resources can change the or alternatives or number of
indicators The local market and their demands for specific products can be crucial for choosing the
best method which affect the priorities of weights Regulation of every regions as it was mentioned
before can change the project requirements and indicators
The type of the project was a residential building that has its own characteristics but for
instance a school or hospital project would demand a higher functionality and lifetime because of their
distinctive operation kind and evidentially can be considerable in decision-making process to the end
step Special project due to their unique requirements often do not consider all criterions For
instance emergency health stations demanded during the Virus pandemic period have their own
material choose design enhancement and priorities on requirements
Future studies
Due to novelty of this subject there are numbers of studies still remained without coverage
which might be studied in future
Decision making study on two real projects with the input data of professional
modular and traditional constructors
Due to the lack of information over literature there were so many elements that have been
estimated by hypothesis and survey information therefore it is crucial to find these data in order to
do a precise study with real numbers These data can be obtained by requests to industry players to
have access of real project details including budget schedule material consumptions etc By this
action the liability of the study can be improved and accurate results can be achieved Thus a
decision-making process can be done to find out which alternative can be more sustainable
Technological studies about the production line of a modular off-site plant by factory
and on-site visits
There are still uncertainties about the status of use of automation productivity rate etc which
have to be analysed closely Modular construction was suggested as an example of industrialization in
construction industry to improve the productivity rate but corresponding to past survey the majority
of constructors are not benefiting from automation in their production lines and assembly processes
A study is needed on different phases of a project that have to be monitored and analysed scientifically
in order to find challenges errors and possible solutions to make this method even more sustainable
A survey about challenges in modular construction and its possible solutions to find
adequate solutions
Challenges have to focused more on this method because its players are still suffering from
the incompatibility of construction industry and the projectrsquos old conditions with innovative solutions
Series of interviews with experts factory visits etc have to be done to hear the voices of them and
then researchers to find solutions to update the industry and help them for growth
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
87 | P a g e
Recommendations
Cooperation between industrial players and scientific researchers in offsite
construction
Numbers of contrasts where found in the data and results among literatures professional
participants of survey and the decision-making study which shows a poor status of cooperation
between scientific researchers and professional players in the construction industry It is obvious that
the real data from the constructors designers etc in real projects are more reliable than scientific
estimation which in this case were based on BIM models and approximate calculations without any
interruption effects of common challenges in industry There were few participants who did not want
to share their project details in public or even education purposes or in a case one of the most
innovative players in modular industry responded their lack of available time to respond the survey
by direct email These attitudes can increase the gap between two vital elements for improvement
which are science and industry in construction society and to reduce it cooperation must be increased
specially in off-site society
Education about industrialization in construction and its alternatives
The idea of lack of education among engineers and architects who enter the professional
society about off-site construction methods was proved by the collected information from survey
participants which can cause problems in the projectrsquos design coordination and execution processes
These series of errors must be resolved by updating the education resources about innovative
methods such as off-site construction industrialization in construction concept rather than traditional
on-site methods that still occupy most of the educational courses these actions can improve the
common challenges in construction industry such as productivity problem and sustainability rate by
encouraging the researchers even far beyond the boundaries of investigations and make the way
possible to find more innovative solutions such as robotic fabrication 3D concrete printing etc
Establishing international and regional adequate codes
Use of automation is suggested by the researchers and industry players to raise the
productivity and sustainability in construction as the other industries which resulted positively
However constructors and manufacturers are suffering from a lack of exitance of international united
codding for their production line and boundaries and uncertainties by local regulations
To resolve these issues participants addressed an international code similar to what on-site
traditional methods have which the responsibility of creation of these codes are on the shoulders of
researchers and professional experts with a mutual partnership that is only possible with cooperation
of industry with science as it mentioned before
Synchronizing the contract conditions with modular construction conditions
There are numbers of problems in terms of contract conditions such as misunderstanding by
final client who is the end home buyer who ldquobelieves the factory to be the builder and the actual
independent builder to be a sales agent for the factoryrdquo one of the participants mentioned A
recommended solution for this problem is to define the relationships between the participants of
projects their responsibilities For instance requiring the builders customer to sign a disclosure
acknowledgement from that describes the relationship in detail In addition there is a lack of quality
partners on site The problem starts when on-site participants realize the advantages of modular
construction they tend to increase their prices for services which can increase the final prices of
project Another challenge which modular projects can face is the lack of delivery of project on agreed
time with an unacceptable quality of on-site execution The professionals answered that the
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
88 | P a g e
responsibility of ensuring that the work is done properly belongs to the builder which any ldquodelays in
this can result in postponed transport of product and interest through demurrage chargesrdquo
These problems must be solved by defining unique types of contracts that are adapted with
the off-stie construction nature and be obeyed by all the participants globally
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc
The only value that the market considers choosing modular method over traditional
construction is to be cheaper while majority of people the media and even professional engineers do
not understand the capabilities of modular construction Many people continue to confuse this form
of construction with HUD on frame products Another wrong perception that the publicmarket
believes is that the prefabrication methods limits the design options while some players believe that
the reverse is the case Therefore by using one of the main advantages of modular construction which
is shorter schedule the market can be dominated by modular projects and the more cases they
deliver the more recognised this method would be among the public and at the end the superior
nature of modular approach can be proved Another solution is a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Many of these wrong perception and misunderstandings can be
clarified by well-organized advertisements about several advantages that modular construction have
in comparison with conventional methods
Changes in financial strategies and adapting them with off-site construction nature
Financial assists which are crucial for kind of projects that are dependent to these aids are
not harmonized with modular project processes where there are argues that until the first deliveries
of elements to the site location and their assembly these aids will not be reachable This issue creates
pressure on cash flow of project where bank finance is involved Changes in contract conditions and
education for financial supporters are recommended solutions to improve the partnerships in
projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
89 | P a g e
6 References 1) Balasbaneh AT Ramli MZ A comparative life cycle assessment (LCA) of concrete and
steel-prefabricated prefinished volumetric construction structures in Malaysia Environ Sci
Pollute Res (2020) httpsdoiorg101007s11356-020-10141-3
2) Doran D and Giannakis M (2011) An examination of a modular supply chain a
construction sector perspective Supply Chain Management Vol 16 No 4 pp 260-
270 httpsdoiorg10110813598541111139071
3) Lawson RM Ogden RG Bergin R 2012 Application of modular construction in high-rise
buildings Journal of Architectural Engineering httpsdoi101061(ASCE)AE1943-
55680000057
4) Diez R et al (2007) lsquoAUTMOD3 The Integration of Design and Planning Tools for Automatic
Modular Constructionrsquo International Journal of Advanced Robotic Systems httpsdoi
1057725671
5) Lee J Park M Lee H ampamp Hyun H (2019) Classification of Modular Building
Construction Projects Based on Schedule-Driven Approach Journal of Construction
Engineering and Management 145(5) 04019031 httpsdoi101061(asce)co1943-
78620001656
6) Barbosa F Woetzel J Mischke J Ribeirinho M Sridhar M Parsons M Brown S
(2018 July 09) Reinventing construction through a productivity revolution Retrieved
September 28 2020 from httpswwwmckinseycomindustriescapital-projects-and-
infrastructureour-insightsreinventing-construction-through-a-productivity-revolution
7) Quale J Eckelman MJ Williams KW Sloditskie G and Zimmerman JB (2012)
Construction Matters Comparing Environmental Impacts of Building Modular and
Conventional Homes in the United States Journal of Industrial Ecology 16 243-253
httpsdoi101111j1530-9290201100424x
8) Horwitz-Bennett Barbara (2020) Rising to the challenge sl Modular Building Institute
(MBI)
9) Lu N amp Korman TM (2010) Implementation of Building Information Modeling (BIM) in
Modular Construction Benefits and Challenges
10) Institute Modular Building 2019 Permanent Modular Construction Canada Modular
Building Institute
11) Josa A (2012) Introduccioacuten a MIVES y el anaacutelisis multicriterio Jornada sobre la Importancia
de un meacutetodo para la toma de decisiones modelo MIVES para una ingenieriacutea sostenible
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
90 | P a g e
12) Aye L Ngo T Crawford R H Gammampila R amp Mendis P (2012) Life cycle greenhouse
gas emissions and energy analysis of prefabricated reusable building modules Energy and
buildings 47 159-168
13) Kamali M amp Hewage K (2016) Life cycle performance of modular buildings A critical
review Renewable and sustainable energy reviews 62 1171-1183
14) Lawson M Ogden R Goodier C (2014) Design in Modular Construction London CRC
Press httpsdoiorg101201b16607
15) Generalova E M Generalov V P amp Kuznetsova A A (2016) Modular buildings in modern
construction Procedia engineering 153 167-172
16) Thompson J (2019) Modular Construction A Solution to Affordable Housing Challenges
Cornell Real Estate Review 17(1) 21
17) Modular construction for multifamily affordable housing (2018) WSP
httpscdnymawscomwwwnibsorgresourceresmgrosccepa-modular-construction-
forpdf
18) Hammad A W A amp Akbarnezhad A (2017) Modular vs conventional construction a
multi-criteria framework approach In ISARC Proceedings of the International Symposium on
Automation and Robotics in Construction (Vol 34) IAARC Publications
19) Ferdous W Bai Y Ngo T D Manalo A amp Mendis P (2019) New advancements
challenges and opportunities of multi-storey modular buildingsndashA state-of-the-art review
Engineering Structures 183 883-893
20) Bertram N Fuchs S Mischke J Palter R Strube G amp Woetzel J (2019) Modular
construction From projects to products McKinsey amp Company Capital Projects amp
Infrastructure 1-34
21) Hsu P Y Aurisicchio M amp Angeloudis P (2020) Optimal logistics planning for modular
construction using multi-stage stochastic programming Transportation Research Procedia
46 245-252
22) Rausch C Nahangi M Perreault M Haas C T amp West J (2017) Optimum assembly
planning for modular construction components Journal of computing in civil engineering
31(1) 04016039
23) Connor G Jones C E amp Finney S J (2014) Easing future low voltage congestion with an
AC chopper voltage regulator httpsdoi 101061(ASCE)CO1943-78620001001
24) Ahn Y H amp Kim K T (2014) Sustainability in modular design and construction a case
study of lsquoThe Stackrsquo International Journal of Sustainable Building Technology and Urban
Development 5(4) 250-259
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
91 | P a g e
25) Gunawardena D Mendis P Ngo D Aye L amp Alfano J (2014) Sustainable prefabricated
modular buildings httpsdoi 10131402148473920
26) Olearczyk J Al-Hussein M Bouferguene A amp Telyas A (2009) Virtual construction
automation for modular assembly operations In Construction Research Congress 2009
Building a Sustainable Future (pp 406-415)
27) Woźniak-Szpakiewicz E (2016) EU migrant crisis and increasing demand for modular
construction modular social housing complex for refugees in Munich In Back to the Sense
of the City International Monograph Book (pp 921-931) Centre de Poliacutetica de Sogravel i
Valoracions
28) Wunderlich-Malec 2019 The Modular Solution to Reduce Total Construction Costs
httpswwwslidesharenetJoelGil2wuderlich-malec-engineering-modular-construction
29) HAMMAD AWA AKBARNEZHAD A WU P WANG X and HADDAD A 2019 Building
information modelling-based framework to contrast conventional and modular construction
methods through selected sustainability factors Journal of Cleaner Production [en liacutenea] vol
228 pp 1264ndash1281 ISSN 0959-6526 DOI httpsdoiorg101016jjclepro201904150
Disponible en httpwwwsciencedirectcomsciencearticlepiiS0959652619312296
30) HONG J SHEN GQ LI Z ZHANG B and ZHANG W 2018 Barriers to promoting
prefabricated construction in China A costndashbenefit analysis Journal of Cleaner Production
[en liacutenea] vol 172 pp 649ndash660 ISSN 0959-6526 DOI
httpsdoiorg101016jjclepro201710171 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS0959652617324782
31) LOPEZ D and FROESE TM 2016 Analysis of Costs and Benefits of Panelized and Modular
Prefabricated Homes Procedia Engineering [en liacutenea] vol 145 pp 1291ndash1297 ISSN 1877-
7058 DOI httpsdoiorg101016jproeng201604166 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS1877705816301734
32) NEELAMKAVIL J 2009 Automation in the Prefab and Modular Construction Industry [en
liacutenea] Sl sn DOI 1022260ISARC20090018 Disponible en
httpwwwiaarcorgpublicationsproceedings_of_the_26th_isarcautomation_in_the_pref
ab_and_modular_construction_industryhtml
33) SANTIAGO M ALBERTO J MARIA NJ and PATRICIA G 2008 Building industrialization
robotized assembly of modular products En M ONORI (ed) Assembly Automation [en
liacutenea] vol 28 no 2 pp 134ndash142 ISSN 0144-5154 DOI 10110801445150810863716
Disponible en httpsdoiorg10110801445150810863716
34) McGeorge D amp Zou P X (2012) Construction management new directions John Wiley amp
Sons
35) Fieldwire (2018) Why the Construction Industry Is Stuck in the Past
httpswwwfieldwirecomblogis-construction-stuck-in-the-1960s
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
92 | P a g e
36) Construction industry - Office for National Statistics (2019) ONS
httpswwwonsgovukbusinessindustryandtradeconstructionindustry
37) Timmer M P O Mahony M amp Van Ark B (2007) EU KLEMS growth and productivity
accounts an overview International Productivity Monitor 14 71
38) Smith A (2011 September 22) Agile and Lean for Construction SlideshareNet
httpswwwslidesharenetadrianlsmithagile-and-lean-for-construction-9384237
39) The massive opportunity of digitization in Engineering amp Construction (2019)
JourneyappsCom httpsjourneyappscomblogmassive-opportunity-digitization-
engineering
40) Tapscott D amp Tapscott A (2018) Blockchain Revolution How the Technology Behind
Bitcoin and Other Cryptocurrencies Is Changing the World (Reprint ed) Portfolio
41) Can Blockchain Fix the Construction Industryrsquos Productivity Problem (2018) Enstoa
httpsenstoacomblogcan-blockchain-fix-construction-industrys-productivity-problem
42) Itanola M (2019 June 5) Hey Quantity Surveyor is BIM going to take your job Blaze
Threads httpswwwblazethreadcomhey-quantity-surveyor
43) BIM Community (2017) Remodeling Construction Industry with Digitization BIM and
Reality Capture httpswwwbimcommunitycomnewsload563remodeling-
construction-industry-with-digitization-bim-and-reality-capture
44) Kolarevic B (2003) Digital production Architecture in the digital age design and
manufacturing 38-63
45) Labonnote N Roslashnnquist A Manum B amp Ruumlther P (2016) Additive construction State-
of-the-art challenges and opportunities Automation in construction 72 347-366
46) Kapoutsis A C Chatzichristofis S A Doitsidis L de Sousa J B Pinto J Braga J amp
Kosmatopoulos E B (2016) Real-time adaptive multi-robot exploration with application to
underwater map construction Autonomous robots 40(6) 987-1015
47) Khoshnevis B (2004) Automated construction by contour craftingmdashrelated robotics and
information technologies Automation in construction 13(1) 5-19
48) R Alice (2019) CRYSTAL PALACE SHOWER TALK httpsbloginoxstylecomencrystal-
palace
49) Eba (2014) HISTORY ldquoballoon framingrdquo the first prefabricated building system (US)
Architecture for the 99 httpslikemyplacewordpresscom20140214history-balloon-
framing-the-first-prefabricated-building-system-us
50) Peter Goumlssel Arnt Cobbers Oliver Jahn (2012) A Brief History of Prefab ArchitectureWeek
httpwwwarchitectureweekcom20121003design_1-1html
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
93 | P a g e
51) Merin G (2018) AD Classics Habitat 67 Safdie Architects ArchDaily
httpswwwarchdailycom404803ad-classics-habitat-67-moshe-safdie
52) Sveiven M (2018) AD Classics Nakagin Capsule Tower Kisho Kurokawa ArchDaily
httpswwwarchdailycom110745ad-classics-nakagin-capsule-tower-kisho-kurokawa
53) Modular Building Experience | Deluxe Modular (2020)
httpswwwdeluxemodularcomexperience
54) Applications | Modular Construction | Bathroom Pods (2020) Howick Ltd
httpswwwhowickltdcomapplicationsmodular-constructionbathroom-pods
55) Project types (2018) Panel built httpswwwpanelbuiltcomblogmodular-building-types
56) Mobile Mini Merger - WillScot (nd) Willscot httpswwwwillscotcomAboutMobile-
Mini-Merger
57) Teague L (2017) Urbantainer breaks down the negative stereotypes of modular building
Frameweb httpsframewebcomarticleurbantainer-breaks-down-the-negative-
stereotypes-of-modular-building
58) Modular construction (nd) SteelconstructionInfo
httpswwwsteelconstructioninfoModular_construction
59) Modular V (2020) What Is Modular Building Construction Your Ultimate Guide Vanguard
httpsvanguardmodularcomabout-modular
60) Permanent Modular Construction Annual Report 2019 | Modular Building Institute (2019)
MBI httpswwwmodularorgHtmlPageaspxname=pmc-2019-home
61) Modular Construction Foundation (2020) Triumph Modular
httpswwwtriumphmodularcomabout-triumphour-servicesconstruction-
managementfoundations
62) Weights and Dimensions (2020) ITF httpswwwitf-oecdorgweights-and-dimensions
63) Sajip J (2019) Modular Construction A Sustainable Building Method NY-Engineers
httpswwwny-engineerscomblogmodular-construction-a-sustainable-building-
methodWeights and Dimensions (2020 August 28) ITF httpswwwitf-oecdorgweights-
and-dimensions
64) Muresan F (2019) What is Modular Construction NY-Engineers httpswwwny-
engineerscomblogwhat-is-modular-construction
65) ADVANTAGES of using SurePods prefabricated modular bathroom pods (nd) SurePods
httpswwwsurepodscomspeed
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
94 | P a g e
66) EasyPads - The easy-to-use foundation system for modular buildings (2019 March 23)
EasyPads - Foundation System httpseasypadscouk
67) Honrubia M amp Mendonccedila A (2019 June 18) The Benefits of Reusable and Modular
Constructions Ennomotive httpswwwennomotivecomreusable-modular-
constructions
68) Cosentino (2020) Discover Cosentino and all the characteristics of its materials
httpswwwcosentinocom
69) Al-Hussein M Manrique J D amp Mah D (2009) North Ridge CO2 analysis report
comparison between modular and on-site construction University of Alberta Canada
70) Vickers H (2017) Modular construction 4 health and safety benefits Building 4 Education
httpsb4edcomArticlefour-health-and-safety-benefits-of-modular-construction
71) PRISM (2020) HGA and The Boldt Company build STAAT ModTM critical care units to
address the COVID-19 hospital bed shortage PRISM Modular construction 4 health and
safety benefits Building 4 Education httpsb4edcomArticlefour-health-and-safety-
benefits-of-modular-construction
72) Harrouk C (2020 September 28) Mayor of London Launches Housing Design App to
Transform Construction ArchDaily httpswwwarchdailycomauthorchristele-harrouk
73) Schoenborn J (2012) A case study approach to identifying the constraints and barriers to
design innovation for modular construction (Doctoral dissertation Virginia Tech)
74) Casas prefabricadas inHAUS (nd) servicio post-venta casa modular archivos InHAUS
httpscasasinhauscomfranceestagservicio-post-venta-casa-modular
75) Catalunya U U P (nd) MIVES mdash Departamento de Ingenieriacutea Civil y Ambiental mdash UPC
Universitat Politegravecnica de Catalunya UPC httpsdecaupceduesproyectosmives
76) Kim D (2008) Preliminary Life Cycle Analysis of Modular and Conventional Housing in
Benton Harbor MI (Doctoral dissertation)
77) Gangolells M Casals M Forcada N amp Macarulla M (2014) Analysis of the
implementation of effective waste management practices in construction projects and sites
Resources conservation and recycling 93 99-111
78) Alarcon B Aguado A Manga R amp Josa A (2010) A Value Function for Assessing
Sustainability Application to Industrial Buildings Sustainability 3(1) 35ndash50
httpsdoi103390su3010035
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
95 | P a g e
Anexo 1
a) Indicators resources
o Prefabricated Steel Modular (PSM)
Table A1 1 ndash Cost of project PSM (Hammad 2019)
Table A1 2 -Time of project PSM (Hammad 2019)
Table A1 3 - Energy utilized during construction (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
96 | P a g e
Figure A1 1 - Injury risks for workers (Hammad 2019)
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
97 | P a g e
Figure A1 3 - Co2 amount (Aye 2011)
o Prefabricated Concrete Modular (PCM)
Figure A1 4 - Total project cost (Balasbaneh 2020)
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
98 | P a g e
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter)
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020)
o Prefabricated Timber Modular (PTM)
Figure A1 8 - Co2 emission (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
99 | P a g e
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
o Traditional Reinforced Concrete (TRC)
Table A1 6 6 - Projects cost (Hammad 2019)
Table A1 7 - Projects schedule (Hammad 2019
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
100 | P a g e
Table A1 8 - Energy utilised during construction process (Hammad 2019)
Figure A1 9 - Injury risks for workers (Hammad 2019)
Figure A1 10 - Noise level (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
101 | P a g e
Figure A1 11 - Greenhouse gas emission (Aye 2011)
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
102 | P a g e
Anexo 2 1 Survey Q amp A
Q How many years of experience do your company have in modular construction
industry Table A2 1 - Professional experience of the company
Company Responses
A 10-15
B 10-15
C 20-30
D 20-30
E 30-50
Q How many years of experience do you have in the modulartraditional construction
and what is your job position Table A2 2 - Personal experience of participant
Company Responses
A 15 years
B 13 years sales manager
C 30 years of which the last 25 have been as design architect
D Quantity Surveyor
E 3 years Foreign Trade Manager
Q What types of modules your company products in terms of material Table A2 3 - Type of modules
Company Responses
A Wood Steel
B Wood
C Wood
D Wood
E Counter and Fibber cabins Steel
Q Which types of projects you did so far Table A2 4 - Type f projects
Company Responses
A Residential houses
B Schools Residential houses Commercial buildings
C Residential houses
D Schools Residential houses Hospital Commercial buildings
E Schools Residential houses hospital Commercial buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
103 | P a g e
Q Num of employees num of factories and num of modules build Table A2 5 - Characteristics of production range
Company Responses
A 80 employees 1 factory 200 modsyear
B 130 1 490
C 15
D 50 Employees 2 factories 80 build
E 250 employees 2 factories 100000 m2 prefabricated 5000 containers 1000 cabinets TURKEY
Q What was your motivation to choosework in modular construction Table A2 6 - Motivation for doing modular construction
Company Responses
A High demands in market and lack of provide Innovation
B Economic profit
C Environmental benefits High demands in market and lack of provide Innovation Shorter construction schedule due to need Economic profit
D Shorter construction schedule due to need Innovation
E Economic profit
Q Do you have sup-contracts for your panels or they had built in your factories what
is the reason for this decision Table A2 7 - Panel production conditions
Company Responses A build our own
B PE design and approvals fire suppression design and installation ceramic tile Energy Star design and inspection are all subcontracted
C All built in house in our own workshop We have developed our own unique systems which are not available elsewhere
D build in factory - programme cost
E
EPS isolated panels are produced in our factories The other are being purchased from domestic market Standard is EPS isolation and its fixed costs are lower because of quantity The others are not standard investment in production is not feasible
Q What is the level of automation technologies you use in off-site and on-site
production and assembly Table A2 8 - Level of automation
Company Responses
A Extraordinarily little today investing in this heavily this year want to get to 80
B 20
C Off-site 60 on site 20
D 20
E 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
104 | P a g e
Q Does A modular project have a smaller number of labours Less wages of salary off-
site and on-site due to specialization of workforce Does the more value added in
each hour of work can compensate Table A2 9 - Laboral status
Company Responses
A Fewer labour hours and at less cost per hour 1 hour in the factory is equal to 4 on site
B Prefabricated systems-built modular construction generally has a smaller on-site labour force for a shorter period
C Labour similar but more efficient working off site
D Yes (less no of workers and wages) - no need for special work force
E -
Q Do you have any case of recycle and reuse the structuralnon-structural elements in
your projects Table A2 10 - Recycle and Re-use
Company Responses
A Yes
B Yes
C No
D No
E Yes
Q Do you upgrade the modules with other environmentally friendly technologies such
as solar panels in your projects Please give us some examples Table A2 11 - Innovative technology integration
Company Responses
A Our homes are all self-powered only company in the world to be doing this
B
This factory allows for site installation of solar panels and other energy savings processes on site by the independent builderbuyer of our modular building materials Modular makes the most sense to be used by architects and builders with environmentally friendly tech
C
Modules (flat packed floor wall and roof components) are constructed of ply and highly insulated with non-petroleum-based insulation (recycled glass as a fibre) Solar panels fitted as an add on to completed building
D None yet not been asked
E Solar technology is YES
Q Automation in off-site production generates less or more waste of material There
are some argues about less waste generation in manual activities because of better
sense of material resistance by normal labour (wooden material for instance) Table A2 12 - Automation status on waste generation
Company Responses
A we are not automated yet but believe automation will be much more efficient use of materials
B In our experience as a custom modular manufacturer automation has a significant cost that may not be recoverable for many months if not years- millions of dollars in cost of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
105 | P a g e
components set up and training versus hourly wage and benefits of trained factory workers
C Waste is much reduced and a proportion of the waste is remanufactured to smaller items or sold on to handymen
D Would be less waste but we do not use much automation
E -
Q How much reduction does off-site modular construction has in generating ldquowasterdquo in
comparison with traditional construction methods Table A2 13 - Reduction of waste
Company Responses
A 70 less waste
B I am unable to provide an answer to this question
C
As we are timber people emissions are low regardless of construction methods Steel and concrete use are kept to a minimum and these are the high emission materials
D We are still working on our carbon footprint
E 15 less carbon emission
Q How much reduction has in ldquoenergy consumptionrdquo off-site in comparison with
conventional on-site construction What about during the operation phase Table A2 14 - Energy consumption status
Company Responses
A Our homes are not positive from an energy perspective
B
Energy consumption of a factory is known and relatively constant on a weekly monthly and annual basis The modular components for a two-box ranch style house require 3 workdays on our factory floor and 4 more days in final finish prior to shipment A competent and experienced modular builder can many times finish the entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-built house could require as much as 4 months for the same completion
C Not assessed but doubt there is much difference
D We are still working on our carbon footprint
E 30 energy saving
Q Did you deliver any projects for providing emergency services in Covid-19 period You
can mention the projects in the other section Table A2 15 - Delivery of projects in COVID-19 pandemic period
Company Responses
A No
B No
C No
D No
E Yes
Q Did you construct any projects for world aid organizations and charities You can
mention them in the other section
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
106 | P a g e
Table A2 16 - Aid organization project delivery
Company Responses
A No
B No
C No
D No
E Yes
Q Do you offer post-sale services to your clients Table A2 17 - Post-sale services to client
Company Responses
A Yes
B No
C Yes
D Yes
E Yes
Q How much was your initial costs estimate (Factory set up etc) How long was the
investmentrsquos payback period Table A2 18 - Initial costs
Company Responses
A 20 million Canadian dollar 5-year payback
B What costs Factory set up or cost of modular product sold to builders What about labour engineering transportations etchellip
C The business has been building up over decades so it is not possible to isolate specific costs
D -
E 15 million USD 5 years
Q Which factors can change the initial costs Table A2 19 - Effective factors on initial costs
Company Responses
A Level of automation Product types and production range Less sub-contracts Site location
B Design of modular building- ie roof system high wind heavy snow loads etchellip Product types and production range Site location
C Financing Level of automation Product types and production range Less sub-contracts
D Level of automation Product types and production range Site location
E Level of automation Product types and production range
Q Can component re-use building portability and the life cycle value of materials be
used as a strategy to ldquocompensaterdquo for higher initial construction costs Table A2 20 - Re-use effect on budget
Company Responses
A -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
107 | P a g e
B
We use many lumber cut-offs PVC drainpipes and conduit and dry wall pieces over many modular orders Unusable drywall shingle and PVC pieces are collected and sent out for recycling Wood is collected and recycled into mulch product or used for heating by others
C Not easily Our methods (flat pack) due not lend themselves to building portability
D -
E 50 years life span of the products
Q Which factors did you consider for choosing modular construction over traditional
method Table A2 21 - positive factors about modular construction to be chosen
Company Responses
A traditional construction is broken
B
Speed ease and cost of overall construction Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
C Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
D Transportation costs and boundaries Local salary wages
E Transportation costs and boundaries Local salary wages Environmentally friendly
Q Do use BIM in your projects what are the challenges in using BIM Table A2 22 - Use of BIM in projects
Company Responses
A 100 BIM from conceptual to finished models
B No
C No
D No
E No
Q What effects the production line can have on the design Are there any boundaries
on the architectural design Table A2 23 - Influence of production line on design
Company What effects the production line can have on the design Are there any boundaries on the architectural design
A No you just need to design with our subassemblies in mind
B This factory maximum module dimension capability is 15rsquo9
C Workshop prefabrication gives the architect far more design freedom
D Width of building for transport to make economically viable
E No
Q Is there any lack of knowledge from architects or design engineers in modular industry
about production line processes transportation limitations etc
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
108 | P a g e
Table A2 24 - Lack of knowledge among experts
Company Responses
A Yes
B No
C NA
D Yes
E Yes
Q How state transport regulation and approval can harm the projects in cost and time
Have you experience delays in your schedules because of those Table A2 25 - Transportation regulation effect on projects
Q Does the concept of transportable materials add extra costs on the project Do the
reduction of material waste and multiple discounts can ldquocompensate the lossrdquo Table A2 26 ndash Transportable material choice and its effects
Company
Does the concept of transportable materials add extra costs on the project Do the reduction of material waste and multiple discounts can ldquocompensate the lossrdquo
A Transportation costs are offset by speed of production and reduced financing costs for the project
B Not significantly
C See 26 The reverse applies
D No
E No
Q What are the difficulties in using automation in off-site production processes Table A2 27 - Challenges of using automation
Company Responses
A Codding Integration with advanced software
B Cost
C -
D Integration with advanced software
E Codding Cost Lower salaries of manual processes by labour
Company
How state transport regulation and approval can harm the projects in cost and time Have you experience delays in your schedules because of those
A Yes Some areas are slow to respond
B
Yes Some states in the US are more difficult to ship oversized and ldquosuper loadsrdquo through This adds both time and expense to the projects
C No Our company prefabricates and flat packs so all components are within or close to legal load limits
D No
E Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
109 | P a g e
Q Which problems exist in modular construction in terms of contracts What are the
solutions Table A2 28 - Contract condition in modular industry
Q What are the challenges in defining responsibilities among participants of a project
due to the changing most of the activities to precast solutions Table A2 29 - Participation status in modular projects
Company
What are the common errors than can harm the synchronization of productivity between off-site production transportation and on-site installation progress For instance less demands on-site caused
A Lack of quality partners on site that see the benefits of modular and therefore increase their pricing
B
The builder owns the responsibility to ensure that site work is done on time and correctly Delays in this can result in postponed transport of product and interest through demurrage charges
C Provided control is tight none
D -
E -
Q Considering all components are prefabricated offsite what is the role of an outside
general contractor Table A2 30 - Role of outside general constructor
Company Responses
A will always need some component of site work to complete the project
B
An outside general contractor is the independent builder The modular factory is a material vendor to the general contractor The general contractor is responsible for all site work and permits as well as storage- installation- and finish of the modular product forming the house or structure they are building
C We do not use outside general contractors All stages from earliest concept design to completed building are in house
Q How often advantageous changes must be done in the production line and what are
the challenges
Company Which problems exist in modular construction in terms of contracts What are the solutions
A Every state has a different building code need a universal code
B
In some cases the end home buyer believes the factory to be the builder and the actual independent builder to be a sales agent for the factory Our company addresses this through accuracy in the relationship described on our website and social media as well as requiring the builders customer to sign a disclosure acknowledgement from that describes the relationship in detail
C Banks do not recognise work done until it is erected on site This creates cash flow pressure where bank finance is involved
D -
E Delivery on time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
110 | P a g e
Table A2 31 - Changes in production line and its effects
Company Responses
A Slows down production
B This company incorporates changes to product materials or procedures between orders A change in process will not occur that affects only some of the components of an order
C Not sure I can answer that ion the space All means of production have advantages and challenges We have chosen methods and stick to them
Q Do you have sub-contracted players involved in your project for site preparation and
foundation phase etc why Table A2 32 - Site preparation status
Company Do you have sub-contracted players involved in your project for site preparation and foundation phase etc why
A Yes Because we are selling in many geographic areas we need local representation
B No This is the responsibility of our customer- the general contractorindependent builder
C Yes Under direct supervision Their equipment is expensive and not portable It makes sense to use local contractors for footings
D -
E Yes
Q If the onsite foundation is constructed by an outside general contractor are there
additional challenges at the interface in terms of a technology gap the equipment or
tools used the construction experience of workers or in scheduling and phasing of
construction Table A2 33 - Challenges with sub-contractors for site preparation phase
Q What are the wrong perceptions about modular products among market and public Table A2 34 - Wrong perceptions for modular products
Company What are the wrong perceptions about modular products among market and public
A that their only quality is being cheaper
B
In the USA many people the media and even professional engineers do not understand the capabilities of modular construction Many people continue to confuse this form of construction with HUD on frame products
C With our methods (flat pack) that prefabrication reduces the design options The reverse is the case
Company
If the onsite foundation is constructed by an outside general contractor are there additional challenges at the interface in terms of a technology gap the equipment or tools used the constructionhellip
A we need to educate most local subs on our process and reason for doing things a certain way
B Not that directly affects the factory
C No
D -
E -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
111 | P a g e
Q What strategies are taken among manufacturers to either improve the public
perception of modular construction or to promote its advantages to architects and
potential clients Table A2 35 - Solutions for wrong perceptions
Company
What strategies are taken among manufacturers to either improve the public perception of modular construction or to promote its advantages to architects and potential clients
A Going fast Proving the superior nature of our homes by getting more of them into the world
B
There is some cooperation between builders manufacturers architects and engineers to educate the public The national entity is the Modular Home Builders Association See httpswwwmodularhousingcom
C Nothing specific We advertise our advantages and it is enough
Q Any other challenges and recommended solutions for them that you want to add
please Table A2 36 - Recommendations
Company Responses
A -
B -
C The capital cost of equipment Specialised digital equipment is expensive making it difficult for small and medium companies to enter the market
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table of Contents Table of Contents 2
1 Introduction 1
Motivations 1
Orientation of previous studies 1
Gap of knowledge 1
Objectives of the study 2
Survey among the professionals in the modular industry by Online Form 2
Decision-making among three modular methods and conventional option by MIVES 2
Limitations 2
Lack of existence of references related to the subject 2
Non-accessible information from companies and scientific articles 2
Obstacles caused by global lockdown during covid-19 pandemic 2
Organization of the thesis 3
2 State of the art 4
Productivity problem in construction industry 4
Status of productivity rate of construction industry among other industries 4
Reasons of poor productivity 6
Solutions for improvement 7
Brief on modular construction 10
History of modular construction 10
Types of modular product 15
Module architectural types 15
Module structure types 22
Types of modular buildings based on operation period 27
Common uses of modular buildings in the market 27
Construction phases 28
Literature review on possible advantages 31
Scheduling benefits 31
Economic benefits 34
Environmental Benefits 36
Health and security benefits 38
Social-Laboral benefits 39
Modular Construction role in COIVD-19 Pandemic 40
Review on common challenges 41
Initial costs 41
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Architectural challenges 43
Transportation challenges 44
Wrong perceptions among public and real estate market 45
Integration of advanced software 46
Redefining the contracts 46
Supply chain-transportation-onsite assembly management errors 47
3 Common challenges in modular construction industry by a survey 48
Methodology 48
Objective 48
Role of the researcher 48
Ethical considerations 48
Survey setting 48
Development of questionnaire 49
Participant profile 50
Experience amp professions 50
Data collection 51
General information 51
Economic issues 52
Environmental status 52
Social Benefits 53
Initial costs 54
Design limitations 55
Transportation Limitations 55
Project management challenges 56
Social challenges 57
Data analysis amp conclusions 57
Advantages 57
Challenges discussion 58
4 Decision making based on potential advantages among three modular alternatives and
conventional construction method in a project by MIVES software 60
Methodology 60
Objective 60
What is MIVES 60
Data collection process 60
Case Study references 60
Input data 65
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Final indicators 69
Weights 73
Data analysis 76
Indicators Values 76
Criteria Values 77
Requirement Values 81
Sustainability Values (Final decision) 83
5 Conclusions 84
Decision making process 84
Conclusions and discussion 84
ECONOMIC ndash TIME discussion 84
ENVIRONMENTAL discussion 84
SAFETY AND SOCIAL dominance by modular methods 85
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES 85
Effective external factors on decision 86
Future studies 86
Decision making study on two real projects with the input data of professional
modular and traditional constructors 86
Technological studies about the production line of a modular off-site plant by factory
and on-site visits 86
A survey about challenges in modular construction and its possible solutions to find
adequate solutions 86
Recommendations 87
Cooperation between industrial players and scientific researchers in offsite
construction 87
Education about industrialization in construction and its alternatives 87
Establishing international and regional adequate codes 87
Synchronizing the contract conditions with modular construction conditions 87
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc 88
Changes in financial strategies and adapting them with off-site construction nature 88
6 References 89
Anexo 1 95
Anexo 2 102
1 Survey Q amp A 102
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study 4
Figure 2 2 - UK productivity status (Office for National Statistics -ONS) 5
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS) 5
Figure 2 4 - Value added comparison among industries (ennovacom) 6
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom) 6
Figure 2 6 - Fragmentations between construction industry players and their various productivity
rates (McKinsey 2019) 7
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom) 8
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom) 9
Figure 2 9 - Digital construction organization (wwwbimcommunitycom) 9
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom) 10
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom) 11
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom) 11
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8
meters (modulartch) 12
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau) 13
Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
14
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom) 15
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom) 16
Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom) 17
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom) 17
Figure 2 20 - Production steps of floor cassette to walls and their attachment together
(wwwhowickltdcom) 18
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom) 19
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom) 19
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom) 20
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom) 20
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom) 21
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-
Malec (wmengcom) 21
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo) 22
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
23
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported
module (wwwsteelconstructioninfo) 24
Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the
lower levels (wwwsteelconstructioninfo) 25
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other
metals (vanguardmodularcom) 26
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma
Beton) 26
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction
report MBI 2019) 28
Figure 2 34 - Overlaps of phases in modular construction project 29
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom) 30
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method
(McKinsey amp Company 2019) 31
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom) 33
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom) 33
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes) 34
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom) 34
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk) 35
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images) 36
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site
(wwwcadoltocom) 37
Figure 2 44 - various layers of a module building unit including insulations
(wwwsteelconstructioninfo) 38
Figure 2 45 - Compartment floor at junction with external wall and compartment wall
(wwwsteelconstructioninfo) 39
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use
inside convention centres arenas and temporary structures Image courtesy of HGA and The Boldt
Company (prismpubcom) 40
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The
Boldt Company 40
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction
(archdailycom) 41
Figure 2 49 -Balance between Initial costs and Economical benefits 42
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects
(casasinhauscom) 46
Figure 2 51 - synchronization between supply chain transportation and on-site assembly 47
Figure 3 1 - Online office forms for survey use 49
Figure 3 2 - Questionnaire development 50
Figure 3 3 - Participants motivations to start a modular company 51
Figure 3 4 - Re-use potential 53
Figure 3 5 - Contribution in Covid19 epidemic 53
Figure 3 6 - Post sale services por future clients 54
Figure 3 7 - effective factors in initial investments for start-up companies 54
Figure 3 8 - Lack of knowledge among designers and engineers 55
Figure 3 9 - challenges of using automation in off-site plants 56
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study
(WAHammad 2019) 61
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and
conventional methods (Akbarnezhad 2019) 61
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020) 62
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017) 62
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad
2017) 63
Figure 4 6 - Architectural section of multi-residential building (Aye 2011) 63
Figure 4 7 - Structural elements used in modules (Aye 2011) 64
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012) 64
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES) 65
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM
alternatives 71
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software 74
Figure 4 12 - Possible forms of the value function 75
Figure 4 13 - Value function for total project cost in MIVES 75
Figure 4 14 - Criteria normalized values 77
Figure 4 15 - Project Schedule 78
Figure 4 16 - Waste generation ratios 78
Figure 4 17 - CO2 Emission normalized values 79
Figure 4 18 - Recyclability and re-use potential of alternatives 79
Figure 4 19 - Embodied energy consumption and saving potential by reuse 80
Figure 4 20 - Safety advantage of modular construction over traditional method 80
Figure 4 21 - Social criteria 81
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values
analysed by MIVES 81
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind 82
Figure 4 24 - Modular dominance in safety and social requirements over conventional option 82
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives 83
Figure A1 1 - Injury risks for workers (Hammad 2019) 96
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
96
Figure A1 3 - Co2 amount (Aye 2011) 97
Figure A1 4 - Total project cost (Balasbaneh 2020) 97
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
97
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter) 98
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020) 98
Figure A1 8 - Co2 emission (Aye 2011) 98
Figure A1 9 - Injury risks for workers (Hammad 2019) 100
Figure A1 10 - Noise level (Hammad 2019) 100
Figure A1 11 - Greenhouse gas emission (Aye 2011) 101
Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo) 23
Table 2 2 - Possible benefits in projects scheduling 32
Table 2 3 - Economic benefits in modular method 35
Table 2 4 - Environmental Benefits 37
Table 2 5 - Health and safety amp Social-Laboral advantages 39
Table 3 1 - Participantrsquos profiles 50
Table 4 1 - Requirement tree with all indicators which considered for decision making process 67
Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed
to be done on them 68
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other
studied 68
Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow) 68
Table 4 5 - Qualitative indicators 69
Table 4 6 - First hand data over literature 69
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow) 70
Table 4 8 - First hand data over literature 70
Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue) 70
Table 4 10 - First hand data over literature 70
Table 4 11 - Final indicators for PCM 72
Table 4 12 - TRC first-hand data over literatures 72
Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow) 72
Table 4 14 - Final Quantitative indicators used for decision making process 72
Table 4 15 - Requirement weights 73
Table 4 16 - Weights of criteria 73
Table 4 17 - Value function for indicators in MIVES 76
Table 4 18 - Indicators normalized values 76
Table 4 19 ndash Indicator normalized values 76
Table 4 20 - Criteria normalized values 77
Table 4 21 - Criteria normalized values 77
Table 4 22 - Requirement normalized values for four indicators 81
Table 4 23 - SI (Sustainability Indexes related to four alternatives) 83
Table A1 1 ndash Cost of project PSM (Hammad 2019) 95
Table A1 2 -Time of project PSM (Hammad 2019) 95
Table A1 3 - Energy utilized during construction (Hammad 2019) 95
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 96
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 99
Table A1 6 6 - Projects cost (Hammad 2019) 99
Table A1 7 - Projects schedule (Hammad 2019 99
Table A1 8 - Energy utilised during construction process (Hammad 2019) 100
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011) 101
Table A2 1 - Professional experience of the company 102
Table A2 2 - Personal experience of participant 102
Table A2 3 - Type of modules 102
Table A2 4 - Type f projects 102
Table A2 5 - Characteristics of production range 103
Table A2 6 - Motivation for doing modular construction 103
Table A2 7 - Panel production conditions 103
Table A2 8 - Level of automation 103
Table A2 9 - Laboral status 104
Table A2 10 - Recycle and Re-use 104
Table A2 11 - Innovative technology integration 104
Table A2 12 - Automation status on waste generation 104
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table A2 13 - Reduction of waste 105
Table A2 14 - Energy consumption status 105
Table A2 15 - Delivery of projects in COVID-19 pandemic period 105
Table A2 16 - Aid organization project delivery 106
Table A2 17 - Post-sale services to client 106
Table A2 18 - Initial costs 106
Table A2 19 - Effective factors on initial costs 106
Table A2 20 - Re-use effect on budget 106
Table A2 21 - positive factors about modular construction to be chosen 107
Table A2 22 - Use of BIM in projects 107
Table A2 23 - Influence of production line on design 107
Table A2 24 - Lack of knowledge among experts 108
Table A2 25 - Transportation regulation effect on projects 108
Table A2 26 ndash Transportable material choice and its effects 108
Table A2 27 - Challenges of using automation 108
Table A2 28 - Contract condition in modular industry 109
Table A2 29 - Participation status in modular projects 109
Table A2 30 - Role of outside general constructor 109
Table A2 31 - Changes in production line and its effects 110
Table A2 32 - Site preparation status 110
Table A2 33 - Challenges with sub-contractors for site preparation phase 110
Table A2 34 - Wrong perceptions for modular products 110
Table A2 35 - Solutions for wrong perceptions 111
Table A2 36 - Recommendations 111
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
1 | P a g e
1 Introduction
Motivations
Construction industry is suffering for a poor productivity problem during the past 60 years in
comparison with other industries and industrialization in construction was suggested by the
investigators to improving the construction performance by applying production technologies and
design standardized products to be built in off-site plants By searching over the off-site methods
modular construction was found which is benefiting its high sustainability and productivity in
comparison with traditional construction approaches
One of the motivations of these study is to study the advantages of modular construction in
order to demonstrate the superior nature of modular construction over traditional methods to be
presented as a reasonable solution for productivity problem the However there are various of
opinions and argues about the beneficiary of this method so that it was decided to analyse them more
deeply in construction management perspective and even get into contact with the industry for
professional confirmation
Another motivation of this study was to contribute to development of modular construction
and find what is holding it back from developing by discovering the challenges in the modular
construction industry and find possible solutions to help for growth
Orientation of previous studies
During past two decades fewer studies in comparison with other innovative methods have
focused on this subject to analyse this method in economic environmental and functional areas to
discover the benefits and make comparisons with traditional construction methods where possible
McKinsey amp company report on 2019 had general overview on its potential advantages challenges
and its ability to raise the productivity in construction processes while introducing the benefits by
making comparisons in projectrsquos schedule budget and environmental performance among modular
and traditional methods and finally shedding a light on dark side which are the obstacles of growth in
industry and then suggesting possible solutions for improvements In addition there are numbers of
articles focusing on the environmental performance of modular buildings by doing Lifecycle
assessment (LCA) analysis on emissions waste generations and consumption primary resources etc
(Mohammad Kamali and Kasun Hewage et al 2016)
On the other side there are studies that made comparisons between traditional and modular
methods of construction to build a specific project based on BIM models and professional data bases
which led to great results that showed numbers of advantages (AWA Hammad et al 2019) (L Aye
et al 2011) (Ali Tighnavard Balasbaneh at Springer-Verlag 2020)
Gap of knowledge
Taking into account of existent researches there is a gap of knowledge which leads to few
questions that still have remained without answer
bull Confirmation of these benefits that came from scientific researches by professional
players in the industry
bull Do these advantages effect the final decision to choose modular method over
conventional way
bull What are the needs of the market that could be as motivations to use modular
construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
2 | P a g e
bull What are the challenges in the industry in the professional point of view
bull Do the solutions that suggested by researchers can be applied in real projects What
are their professional solutions
Objectives of the study
The importance of this study is to resolve the mentioned questions by accomplishing the
studyrsquos objectives that are separated to be achieved by two methods which are qualitative and
quantitative
Survey among the professionals in the modular industry by Online Form
bull To confirmcorrect the data from literature reviews about benefits of modular
construction
bull Their motivations and reasons to choose modular method
bull What are the constraints and obstacles that they are facing
bull Recommendations and solutions for these problems
Decision-making among three modular methods and conventional option by MIVES
bull To discover the advantages in real study cases by comparisons between four
alternatives
bull To examinate the functionality of every alternative in several criterions
bull How much effective these benefits can be in the final decision based on the
requirements of market and their priorities
Limitations
Several obstacles were seen during the study that effected the methodology and input data
significantly Here are some examples
Lack of existence of references related to the subject
Because of the subjectrsquos novelty or less focus the quantity of references is not enough to
cover all the dimensions of study therefore few estimation hypothesis (that were proved by the
results at the end) and consultants with experts were used instead to provide the necessary
information In addition many of the scientific reports and articles were published few months or
even days before the studyrsquos conclusions so that it was decided to be used immediately to improve
the studyrsquos liability
Non-accessible information from companies and scientific articles
There are innovative companies that because of their privacy policies and protection of
innovation could not provide the necessary data about their projects by request even for academic
uses
On the other side scientific papers in some cases were protected and did not have open
access not even with educational access permissions as requests have been denied by the authors
Obstacles caused by global lockdown during covid-19 pandemic
One of the unpredicted challenges that happened during the study was the virus pandemic
that affected the world negatively and this study was not an exception From on-site project and off-
site factory visits interviews with experts in the industry etc were cancelled Numbers of regions went
to full shutdown including offices factories etc which resulted in reduction of participations in online
survey form as well Therefore it was decided to select five most suitable participants to be analysed
instead of planed massive quantity of results
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
3 | P a g e
Organization of the thesis
⎯ Chapter two state of the art explaining the productivity problem history types and
phases of modular construction and literature reviews on benefits and challenges
⎯ Chapter three The online survey among modular players in the industry
⎯ Chapter four MIVES multi-criteria decision-making approach
⎯ Chapter five Conclusions and findings
⎯ Chapter six Recommendations
⎯ Chapter seven references
⎯ Anexo A (Input data references)
⎯ Anexo B (Survey QampA) 2
Kewwords Sustainability Modular construction MIVES Productivity rate Prefabrication Lifecycle assessment (LCA)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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2 State of the art Productivity problem in construction industry
Status of productivity rate of construction industry among other industries
It has been decades that construction industry is far behind the other industries in terms of
productivity rates Attempts had been done by innovative players in the industry but still the
difference is too enormous which the demands for improvement are needed
Globally construction sector labour-productivity growth averaged 1 percent a year over the
past two decades compared with 28 percent for the total world economy and 36 percent for
manufacturing If construction productivity were to catch up with the total economy the industryrsquos
value added could rise by $16 trillion a year (McKinsey 2019)
It can be said that the building industry is one of the key industries in the general economy
The construction sector typically comprises 8-10 of the Gross Domestic Profit (GDP) of a Western
economy (McGeorge amp Palmer 2002) Therefore only 10 improvement in construction
performance can represent a 25 increase in GDP (McGeorge amp Palmer 2002) Therefore there is
no doubt that improving productivity in the building industry will contribute positively to the general
economy
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The UK has a problem with productivity and the construction sector has poorer productivity
growth rates than any other Simply put productivity is the amount of stuff (whether goods or
services) that is produced by a person in an amount of time UK productivity is lower than it was in
2008 and the construction industry has not seen any significant growth in productivity in the last 20
years (Figure 22)
Figure 2 2 - UK productivity status (Office for National Statistics -ONS)
Not all the regions are struggling at the same rate and the reasons which will be discused
furthermore can be the insterest of regulators to support innovations and new solutions which can
improve the productivity in construction industry(Figure 23)
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS)
The result is that between 70 and 90 of projects exceed the original planned cost and that
the overrun commonly varies between 50 and 100 of budget Construction also suffers from 57
of effort on non-value-added activities compared with 26 within manufacturing (Figure 24)
These productivity rates had experienced severalrises and downs in some periods which is
because of increase of demandas of housing that results a boost in construction industry in order to
provide the needs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 4 - Value added comparison among industries (ennovacom)
Reasons of poor productivity
There are numbers of reasons for this poor performance The industry is extensively
regulated very dependent on public-sector demand and highly cyclical Informality and sometimes
corruption distort the market Moreover poor project management and execution insufficient skills
inadequate design processes and underinvestment in skills development RampD and innovation can
affect the productivity indirectly by decreasing the feasibility and value of the activities and add extra
costs on the project
Another key factor that causes a disruption among construction players which reduces the
average productivity rate is the lack of harmony in productivity between the players In other words
The sector divides mainly in two large-scale players involved in heavy construction such as civil and
industrial work and large-scale housing and a large number of firms engaged in fragmented
specialized trades such as mechanical electrical and plumbing work that act as subcontractors or
work on smaller projects like refurbishing single-family housing The first group manages to have 20
to 40 percent higher productivity than the second However even in the more productive heavy
construction sector there are endemic-potentially structural-challenges in meeting cost and schedule
commitments on megaprojects and players routinely subcontract specialized trades (McKinsey amp
Company 2019) (Figure 26)
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
7 | P a g e
Figure 2 6 - Fragmentations between construction industry players and their various productivity rates (McKinsey 2019)
Solutions for improvement
Nowadays there are solutions which are being used in construction world such reshaping the
regulation rewiring the contractual framework to reshape industry dynamics rethink design and
engineering processes improve procurement and supply-chain management improve on-site
execution infuse digital technology new materials and advanced automation and reskill the
workforce Each region based on their capabilities potential and Infrastructures would take a decision
which ways can be applied to increase the productivity in construction projects in a short or long
period
bull Redefine regulation Actions include streamlining permitting and approvals processes as
Australia has done reducing informality and corruption and encouraging transparency on cost
and performance as the International Construction Measurement Standards project does Many
governments allocate grants for innovation and training Germanyrsquos Federal Ministry of Transport
and Digital Infrastructure (formerly the Federal Ministry of Transport Building and Urban
Development) for instance supports RampD through studies in building materials Best practice
regulation would include moving toward outcome-based more standardized building codes and
consolidating land to promote scale Examples include Singaporersquos move to allow cross-laminated
timber (CLT) for high-rise structures and Japanrsquos promotion of scale through land pooling
bull Re-arrange the contractual framework Establishing a ldquosingle source of truthrdquo on projects for
monitoring progress early potentially supported by collaborative technology helps to minimize
misalignments and enable joint corrective action The data already exist to fundamentally
improve the accuracy of cost and schedule estimates Where players continue to use traditional
contracts they should introduce incentives that significantly improve performance and alignment
not at a trade or package level but at the project-outcome level To move toward best practices
appropriate alternative contracting models such as integrated project delivery (IPD) help build
long-term collaborative relationships Relational contracts will need to become more prevalent
than transactional contracts Sufficient investments in up-front planning incorporating all partiesrsquo
input have been shown to raise productivity substantially Smart Contracts are another example
of these solutions which during recent years is being identified by the major players A smart
contract is a computer program or a transaction protocol respectively which is intended to
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
8 | P a g e
automatically execute control or document respectively legally relevant events and actions
according to the terms of a contract of an agreement or of a negotiation The objectives of smart
contracts are the reduction of need in trusted intermediators arbitrations and enforcement costs
fraud losses as well as the reduction of malicious and accidental exceptions (Tapscott Don
Tapscott Alex amp Savelyev Alexander 2016)
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom)
bull Off-site production shift The biggest impact on productivity would come from moving toward
thinking about construction as a production system where possible encouraging off-site
manufacture minimizing on-site construction through the extensive use of pre-cast
technology assembling panels in factories and then finishing units onsite
bull Improve on-site execution There are four key approaches that are well known in the industry
but have not been universally adopted First is the introduction of a rigorous planning process
the Last Plannerreg System (LPS) is a useful tool to ensure that key activities are achieved on
time and on budget The use of integrated planning tools on a large-scale oil and gas project
for instance achieved a 70 percent increase in the projectrsquos productivity Second is reshaping
the relationship and interactions between owners and contractors and key performance
indicators (KPIs) being agreed on and used at regular performance meetings at which on-site
issues are resolved Complementing commonly used KPIs with additional forward-looking plan
conformance metrics to identify and subsequently reduce variance is critical Third is
improving the mobilization for new projects by ensuring that all pre-work (for instance
obtaining approvals and developing project milestones) has been completed prior to starting
onsite Finally there is a need for careful planning and coordination of different disciplines
on-site along with the application of lean principles to reduce waste and variability On-site
productivity can be increased by as much as 50 percent by implementing a cloud-based
control tower that rapidly assembles accurate data in near real time that is both backward-
looking and predictive (for example using plan conformance and other variability and
inventory metrics)
bull Introduce digital technology advanced automation Companies can start by making 3D
building information modelling (BIM) universal within the company alongside use of digital
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
9 | P a g e
collaboration tools drones and unmanned aerial vehicles for scanning monitoring and
mapping They can put themselves at the cutting edge by using platforms such as 5D BIM to
establish transparency in design costing and progress visualization (Figure 28)
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom)
Advanced analytics enabled by the Internet of Things to improve on-site monitoring of
materials labour and equipment productivity and digital collaboration and mobility tools (such as
construction management apps loaded on mobile devices) to better track progress and collaborate in
real time (Figure 29)
Figure 2 9 - Digital construction organization (wwwbimcommunitycom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Advanced automated equipment and tools such as bricklaying and tiling robots can accelerate
on-site execution The field of digital fabrication (dfab) is quite broad and has many applications Dfab
techniques are based on the combination of computational design methods and automated
construction processes which are typically categorized as subtractive formative or additive
(Kolarevic 2003) The use of subtractive and formative digital fabrication is becoming mainstream in
the prefabrication (off-site) of building parts (eg by using laser cutting CNC milling etc)
In recent years additive fabrication processes especially 3D printing have experienced a
rapid development in many industries As interest in additive fabrication grows research into large-
scale processes begins to reveal potential applications in construction (Labonnote et al 2016)
Existing additive dfab technologies can be classified in two big clusters on-site and off-site
construction technologies On the one hand on-site digital fabrication aims to bring additive
fabrication processes on construction sites
Sousa et al (2016) classified on-site technologies in three main categories large scale robotic
structures mobile robotic arms and flying robotic vehicles A well-known example from first category
is Contour Crafting a robotic structure for 3D printing large-scale construction developed at the
University of Southern California (Khoshnevis 2004)
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom)
bull Reskill the workforce Change in the construction sector cannot be achieved without
investment in retooling a workforce that is aging and changing its makeup through migration
Construction firms and workers need to continuously reskill and train to use the latest
equipment and digital tools In the mix should be apprenticeship programs such as the one
run by Siemens in the United Kingdom training frontline workers in core skills that are
currently underdeveloped and increasing stability in the workforce by breaking seasonality
and cyclicality
Brief on modular construction
History of modular construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
11 | P a g e
bull 1800s
In 1830 he first documented prefabricated home was created by London carpenter John
Manning for his son who was moving from England to Australia Manning built a prefabricated house
in pieces then shipped it to the Land Down Under for easy assembly In 1840 Modular construction
made its way to the United States in response to the housing needs of the California Gold Rush The
Crystal Palace was built for Britains Great Exhibition and remains one of the most famous examples
of early modular construction in 1851 Designed in less than two weeks it utilized light and
inexpensive materials such as iron wood and glass it was constructed in only a few months
Afterward the palace was dismantled moved and rebuilt at another location
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom)
bull 1900s
Augustine Taylor a builder in Chicago devised the balloon-frame method (Figure 212)
enabling walls to be built offsite then transported to the intended construction site for speedy
assembly The rise of catalogue houses happened Between 1908 and 1940 when Sears Roebuck and
Co sold more than 500000 prefab homes through its catalogue straight to consumers At the time
these houses cost less than two-thirds of conventionally built homes and many still exist throughout
the United States
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull WWII Housing Boom
Prefab structures continued into World War Two to meet the growing demand for mass
accommodations for military personnel So-called Quonset Huts or Nissen Huts in the UK
comprised of corrugated steel were introduced for domestic military and institutional uses
When soldiers began returning home in the United States there was a need for rapid
construction for new homes to accommodate these expanding families Once again modular
construction serviced those needs because of its efficiency reduced costs and quick construction
Today many of those units are still in use
bull Prefab in Post-war Europe
The situation in Europe was more difficult although millions of people had no place to live on
the Old Continent due to the destruction of the Second World War people were unwilling to accept
prefabricated construction In Germany which had not only lost 25 percent of its entire housing stock
to bombing but also had to integrate 12 million refugees from former German territories in Eastern
Europe one form of prefabricated housing was used extensively the Nissen Hut (similar to the
Quonset hut) An attempt was also made in post-war France to combat housing shortages with the
help of prefabricated houses In 1944 Jean Prouveacute was already commissioned by the Ministry of
Reconstruction and Urban Planning to build 800 houses as emergency shelters that could be easily
disassembled However only 400 of these Maisons agraveportique which were equipped with an axial
steel frame were ever erected Prouveacutes Alba houses developed for the Abbey Pierres homeless
organization in 1956 were also not a success (Peter Goumlssel Arnt Cobbers Oliver Jahn 2012
architectureweekcom)
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8 meters (modulartch)
bull The Pre-fabulous 60s
The 1960s were a period of social transition in which attitudes towards prefabricated housing
also changed During this era which was marked by space travel the moon landing and even childrens
books that predicted weekend trips to distant galaxies prefabricated construction was discovered both
as a form of artistic expression and as a technical means of creating houses to provide a basis for new
lifestyles which seemed to be imminent in a society characterized by an extremely optimistic view of
progress
These approaches supported the idea of creating megastructures out of residential capsules
the architect Moshe Safdie who was only 24 at the time presented his megastructure Habitat 67 at
the Expo 67 in Montreal 158 housing units consisting of 354 concrete modules assembled as a
conglomerate
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The British architectural group Archigram developed building structures made of residential
capsules as an architectural Utopia which could be expanded at will and joined to form entire cities
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau)
bull Eco-conscious 70s
In 1972 the Japanese architect Kisho Kurokawa built the Nakagin Capsule Tower in Tokyo
housing cells were layered around a prefabricated concrete core to form a fourteen-story residential
tower(Figure 215) The idea of residential capsule megastructures was repeatedly revived as in Zvi
Heckers Ramot housing development in Jerusalem in 1974
The ecology movement of the 1970s brought an end to this euphoria regarding technological
progress and futuristic architectural dreams Now highly modern building materials that did not seem
to be in harmony with a return to nature such as plastic or aluminium fell into disrepute A new
perspective of view replaced as a priority to choose the material types which have the minimum
relation with non-renewable resources
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
bull 90s
This was further exacerbated by the fact that prefabricated elements had often been used to
build high-density housing which was now generally viewed negatively Hence prefabricated building
now came to be associated with the aesthetic and social failure of deindividualized megalomaniac
prefabricated slab housing blocks clustered on the periphery of large cities Thus the acceptance of
the prefabricated house in large parts of Europe remained low up until the 1990s
Prefabricated construction only gradually began to again emancipate itself from a homespun
cheap mass-produced image during the 1990s This is mainly due to the use of computer-operated
programs in the design and production processes The prefabricated housing industry now stands at
a juncture reminiscent of the dynamism of the 1920s and 1930s
bull Modern days
For many years now companies like Muji in Japan or BoKlok in Scandinavia and more recently
also in Poland and England have been supplying prefabricated houses in large numbers In Sweden
alone with only nine million inhabitants 14000 units are sold every year Muji offers models designed
by Kengo Kuma and Kazuhiko Namba that are as simple as they are elegant and far more interesting
than the building-kit houses offered by the multinational concerns Mitsubishi Toyota and Panasonic
(deluxemodularcom 2019)
Countries around the world have enlisted prefab and modular construction methods for
decades For example an estimate of all detached homes that are prefabricated in each country
shows a potential for growth off 84 in Sweden 5 in the United States 9 in Germany 20 in the
Netherlands and 28 in Japan
Today prefabrication and modularization are utilized in the construction of hotels apartment
buildings offices hospitals and schools in every major US city Here is a rundown of the percentage
per industry of prefabricated structures that use some form of modular construction
(deluxemodularcom 2019)
bull 49 of healthcare facilities
bull 42 of college buildings and dorms
bull And 42 of manufacturing buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Types of modular product
Module architectural types
The products can be categorized by its functions dimensions material or type of its operation
etc Here they will be introduced by their general characteristics
bull Bathroom pods
Bathroom pods are commonly used in the construction of most hotels and apartment
buildings these days and becoming used more for residential housing The main drivers for choosing
a modular pod method are
o The cost savings that can be made by building repeated designs in a factory
environment
o Higher quality finish
o Rapid installation
o No trades on site
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom)
Pod Construction Process can be various but the most common steps can be as below
(httpswwwhowickltdcom)
Once the bathroom specification has been finalized and the design completed the
machine files are issued and the framing can be produced
The frames are rolled out of the machine ready for assembly
The panels are assembled
The panels are then fitted with the internal boarding and finished with tiles or a
waterproof lining
The walls floor and roof are joined to create the room structure and the joints sealed
The fixtures and fittings can then be installed including
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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o Bath or shower
o Toilets
o Basins
o Lights
o Mirrors
o Cabinets
The plumbing and electrical components are connected
The pods are then subjected to an electrical test and a pressure test to ensure there
are no leaks (Figure 217)
The pods are then sealed to prevent access ready for transportation
Once on site the pods are slid into position and connected to the power and water services
This process greatly reduces the build time as there are no requirements for trades on the site As the
pods are sealed until the building is completed there are reduced chances of them being damaged
during the building construction phase
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom)
bull Kitchen pods
These pods are less common but are also becoming more frequently used All the appliances
and electrics can be fitted in the factory removing the need for work on site Kitchen pods are ideal
for renovating older or industrial buildings as all the electrical services for the building can be
integrated into the pod From student accommodation to residential flats modular kitchen pods are
suitable for a variety of different sectors and uses and because they are designed bespoke to each
clientrsquos exact specifications they can be anything from a fully fitted kitchen to a small kitchenette
Each modular unit is completely customisable from the worktops to the splashbacks and integrated
white goods
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom)
bull Volumetric and modular rooms
Volumetric and modular rooms are becoming widely used for buildings that have a repetitive
nature Common structures include
bull Hotels
bull Apartments
bull Student accommodation
bull Schools
bull Hospitals
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The benefits of being able to manufacture the complete unit in the factory (including the
bathrooms and fitting of furniture) are
o No weather delays
o Superior finish quality
o All the electrical and plumbing works are done in a controlled atmosphere
o The rooms are sealed before moving to site restricting unauthorized access
Modular rooms production process can be explained as below
Once the building design has been completed and the individual modules specified the
framing components can be made on a just in time basis for site delivery
A typical assembly process would consist of
The floor cassette is rolled and the flooring boards are attached along with the
required insulation and services
The wall and ceiling frames are assembled
The internal lining is fitted and painted
The wall frames are then attached to the floor cassette (Figure 220)
Figure 2 20 - Production steps of floor cassette to walls and their attachment together (wwwhowickltdcom)
The ceiling frames are then fitted
The bathroom can then be fitted and plumbed as well as the electrical fittings and
wiring
The wall and ceiling insulation is added to the frame
The fit-out can then be completed to the desired specification
A hotel module for example would feature carpets bed bedside furniture desk
wardrobe TV system air-conditioning (either vents from main system or stand-alone
unit) bathroom fittings and fixtures
Once completed the electrics are checked and the plumbing is pressure tested
A protective cover is then added for transport and the unit is delivered to site
On-site the units are craned into position and joined
The services are connected
The building is then roofed and clad to the required specification In some cases the cladding
can be fitted during the module assembly further reducing the on-site work
bull Modular Trailers
Outside of modular homes modular trailers are probably the type of modular building that
people are most familiar with These buildings have a lot of applications and are often used as a
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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temporary space solution These trailers can be relocated for several times and are well-equipped as
well Temporary pre-semester school classes and temporary offices can be two examples of these
trailers uses
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom)
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom)
bull Containers
When looking at modular containers they are structures that are typically used to contain a
shiprsquos cargo When Shipping containers were originally created they were designed with modularity
in mind They were required to withstand all kinds of abuse as they journey through some of the
worldrsquos harshest climates From salt water to freezing temperatures a shipping container is meant to
handle the worst of the worst while protecting some of the worldrsquos most precious cargo Comprised
of Corten steel it is in a shipping containers DNA to protect itself from any corrosion or rust and when
they fall off the ship they can take up to a week to sink With more boxes being imported than
exported we have an opportunity to reuse something that is desperately looking for a new home
There has been a shift recently where after these buildings serve their purpose as shipping containers
they are reused fitted with windows doors HVAC units etc And made into an office environment
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The biggest benefit of these containers is they are cheap very portable and easy to install on site
However since most of the time these buildings are retrofitted and remodelled into modular
buildings they usually do not have a lot of flexibility in layout or their dimensions
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom)
Shipping containers act as the exoskeleton of each module The original structure will frame
the HVAC wiring lighting plumbing appliances and wall finish materials Because containers were
built to be durable and mobile they can be transported by train tractor-trailer boat or in some cases
a powerful pickup truck Forklift pockets and corner castings allow the containers to be moved smaller
distances by crane and forklift Shipping containers empower you to move your modular structures
without sacrificing the structural integrity or damaging the modulersquos contents
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull Office Complexes
Office complexes will take several office modules and combine them to assemble a much
larger fully functioning office building Just like all modular construction these modules are
fabricated in a manufacturing environment except when these projects reach the job site they
function more similarly to a full-fledged construction site Generally the module will need a crane to
lift the section from the ground and place it in the correct spot to assemble the building Next the
workers will go through that module and do all things necessary to attach and hook up the piece
Then the next piece is put in place and these steps are repeated and again until the building is
finished
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom)
bull Modular enclosures
For instance one of the major electric utilities in the Northeast using Modular Construction is
Wunderlich Malec Integrated Control Enclosures since 2001 A standard 16times50times11-foot enclosure
with twenty (20) protective relay and control cabinets marshalling cabinets HVAC fire and security
completely installed wired and tested at the factory prior to shipment
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-Malec (wmengcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Module structure types
Modular structure types can be categorized by their materials or structural formation
o Steel Modules
bull 4-sided modules
In this form of construction modules are manufactured with four closed sides to create
cellular type spaces designed to transfer the combined vertical load of the modules above and in-
plane loads (due to wind action) through their longitudinal walls The cellular space provided is limited
by the transportation and installation requirements Depending on location and exposure to wind
action the height of buildings in fully modular construction is in the range of 6 to 10 storeys Modules
are manufactured from a series of 2D panels beginning with the floor cassette to which the four wall
panels and ceiling panel are attached generally by screws The walls transfer vertical loads and
therefore the longitudinal walls of the upper module are designed to sit on the walls of the module
below
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo)
It consists of a modular structure of high strength galvanized steel which is also used as the
basis for building closure Steel physical properties make it one of the most versatile materials for
construction since it is
ELASTIC Steel does not break as it has a great strength and elasticity It is easily workable and it has
a great advantage over traditional construction
RECYCLABLE Steel is 100 recyclable
DURABLE With zinc application it can become galvanized steel which has extraordinary durability
properties
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo)
bull Partially open-sided modules
4 sided modules can be designed with partially open sides by the introduction of corner and
intermediate posts and by using a stiff continuous edge beam in the floor cassette The maximum
width of opening is limited by the bending resistance and stiffness of the edge member in the floor
cassette Additional intermediate posts are usually square hollow sections (SHS) so that they can fit
within the wall width
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull Open sided (corner-supported) modules
Modules may be designed to provide fully open sides by transfer of loads through the
longitudinal edge beams to the corner posts The framework of the module is often in the form of hot
rolled steel members such as Square Hollow Section (SHS) columns and Parallel Flange Channel (PFC)
edge beams that are bolted together
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported module
(wwwsteelconstructioninfo)
bull Modules supported by a primary structure
Modular units may be designed to be supported by a primary structure at a podium or
platform level In this case the supporting columns are positioned at a multiple of the width of the
modules (normally 2 or 3 modules) The beams are designed to support the combined loads from the
modules above (normally a maximum of 46 storeys) The supporting structure is designed
conventionally as a steel framework with beams and columns that align with multiples of the module
width and provides open plan space at ground floor and below ground levels This form of construction
is very suitable for mixed retail commercial and residential developments especially for residential
units above commercial areas or car parking etc particularly in urban projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the lower levels
(wwwsteelconstructioninfo)
o Wood structure
Back in the days of the very first modular buildings wood was the modular construction
material of choice and nowadays it overwhelmingly remains the most used for these projects due
to its abundance and cheaper initial costs Wood-framed modular buildings however have several
notable limitations that might give a property developer pause and may even prove more costly in the
long-term repairs
Wood often lacks the strength necessary to support large building projects especially those
of multiple stories Due to this weakness wood-framed buildings are typically no taller than a few
stories a considerable limitation for someone looking to build a hotel or apartment building as
examples
Wood is flammable and vulnerable to fire which could severely damage the structural
integrity of the building requiring replacement or even worse leading to a total collapse
Wood tends to warp over time resulting in a lower quality building in the years after
completion Combined with its susceptibility to pests and mold selecting wood for a modular
structure may prove to be the more expensive choice in the long term considering repair costsmdasheven
despite initial savings
Wood is among the most wasted materials used in modern construction On average 20 of
construction lumber typically ends up in landfills leaving a larger environmental footprint than other
alternatives (httpswwwdeluxemodularcom)
Considering all those negative points mentioned earlier there are numbers of regions that
still are oriented to wooden structures as this type of housing is part of culture of the society because
of traditional architecture etc therefore typical clients prefer to build the type of accommodation
that they trusted for many years as it became the main demand of market Accessible local resources
availability of necessary knowledge for construction and compatibility of labour forces with this
method are other reasons to be chosen over the other alternatives
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
26 | P a g e
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other metals
(vanguardmodularcom)
o Concrete modules
Precast concrete is a well-established and efficient manufacturing industry and products
range from hollow-core slabs to beams and columns in structural frames Concrete modules can be
manufactured in two ways either from precast 2D wall floor and ceiling panels or as 3D modular
units which are generally cast with an open base Concrete modules are often used in high-security
applications as they are extremely resistant to damage
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma Beton)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
27 | P a g e
Types of modular buildings based on operation period
bull Relocatable Buildings (RB)
Relocatable modular buildings are designed to be reused or repurposed multiple times and
transported to different sites Relocatable Building as defined in the 2015 International Existing
Building Code a partially or completely assembled building constructed and designed to be reused
multiple times and transported to different building sites
bull Permanent Modular Construction (PMC)
PMC is an innovative sustainable construction delivery method utilizing offsite lean
manufacturing techniques to prefabricate single or multi-story whole building solutions in deliverable
module sections PMC buildings are manufactured in a safe controlled setting and can be constructed
of wood steel or concrete PMC modules can be integrated into site-built projects or stand alone as
a turnkey solution and can be delivered with MEP fixtures and interior finishes in less time with less
waste and higher quality control compared to projects utilizing only traditional site construction
Common uses of modular buildings in the market
o Education
Relocatable buildings have become a critical factor in managing student demographics and
increasing enrolments Relocatable classrooms are also ideal for swing space during new construction
or renovation Convenient flexible cost-effective temporary buildings can be delivered and
operational in as little as 24-hours These classrooms are measured for quality and code compliance
by state or third-party agencies through routine and random inspections testing and certification
services Customers may choose single classrooms or arrange multiple buildings in clusters to create
a campus feel MBI members supply steps decks ramps and even furniture Members also offer
lease purchase and lease-to-purchase financing for a variety of public and private school needs
These classrooms are sometimes referred to as temporary portable or mobile classrooms
o Construction-Site
Relocatable buildings have their roots in construction site trailers where speed temporary
space and relocate-ability are important Used as standard field offices construction site and in-plant
buildings are available for immediate delivery Standard construction is wood but steel units are
available to meet non-combustible requirements In-plant buildings are available as single- or two-
story units for industrial environments with noise reducing insulation and are typically moveable by
forklift and include electrical and communications wiring heating air conditioning and even
plumbing
o Healthcare
Relocatable buildings for healthcare applications are designed and constructed to
uncompromising standards of quality A customerrsquos new clinic hospital extension laboratory
diagnostic centre MRI unit dentist office or other medical facility can be open for business and
serving communities in as little as a few days Is your interest in serving patients as quickly as possible
in the safest and aesthetically pleasing environments available These facilities offer quick quiet safe
and clean buildings with an unlimited choice of interior deacutecor and furniture and equipment leasing
o General Administrative and Sales Office
When production demands increase relocatable buildings can temporarily enlarge a current
facility without permanent alterations to the site Because the space is not permanent many
companies are able to expand without the budget approval process necessary for traditional capital
expenses Relocatable offices can be single- and multi-story buildings configured to include
independent offices conference rooms and large open spaces for cubicles or other partition systems
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
28 | P a g e
Large and small businesses as well as local and state governments are typical users of relocatable
office space
o CommercialRetail
Earlier occupancy means quicker return on investment For retail occupancies this can mean
significant cash flow advantages Standard floorplans are available for immediate delivery while
custom buildings are built to specifications in weeks not months Unique to the modular process is
concurrent construction site-work occurs while buildings are being put together in a quality-
controlled factory Typical retail applications include new home sales centers banks golf pro shops
automobile fleet ownerships college bookstores and concession stands If a clientrsquos emerging
business needs are short-term temporary space will accommodate their financial situation space
requirements and deadlines
o Security
Relocatable buildings can be custom built for a variety of access and control situations Toll
booths tickets sales offices guard stands and weigh stations are common applications One and two-
story wood and steel buildings have straight walls or walls that are tilted to improve views and reduce
glare
o EmergencyDisaster Relief
There is simply no other means of providing fast transitional shelter and basic community
needs following natural disasters than relocatable buildings Relocatable buildings can be quickly and
efficiently deployed for emergency shelter medical and educational needs or to accommodate relief
workers
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction report MBI 2019)
Construction phases
Modular construction is the process of manufacturing multiple building sections in a facility
for assembly at a remote building site The building sections called modules will fit together once
assembled on site with plumbing HVAC and electrical connections running throughout One of the
great advantages in the modular construction process is that many of the processes happen at the
same time which can cut the construction time in half There are six common steps to complete a
modular project Design amp Engineering Permits amp Approvals Site Development Plant Fabrication
Transportation and Installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
29 | P a g e
Figure 2 34 - Overlaps of phases in modular construction project
o Step 1 Design
The design phase of the modular building process creates a description of the building usually
represented by detailed plans and specifications A thorough customer consultation with a Palomar
project manager gathers the information required to develop the building plan Once this information
has been gathered the design team will produce the ideal modular building design to fit the customerrsquos
needs
o Step 2 Engineering
Each building design goes through the engineering department for an engineering review Like
site-built structures modular buildings are subject to a series of national state and local building
codes that ensure the building meets a set of standards for safety and performance State level
building codes can be superseded or augmented by local building code requirements and then must
confirm the design proposal meets all applicable building codes
o Step 3 Permits amp Approvals
A construction permit or building permit is a permit required in most jurisdictions for new
construction or major renovations Typical construction permits required can include
Site plan
Building permit
Mechanical permit
Plumbing permit
Concrete permit
Encroachment permit
Sign permit
Flood district development permit
The building owner is ultimately responsible for securing building permits for work on their
property In practice most building owners appoint the general contractor as an authorized
representative so the contractor can obtain the required permits The building owner is advised to
confirm that the general contractor has secured the proper building permits for their project Failure
to obtain the proper permits can result in significant fines penalties and even demolition of
unauthorized construction
o Step 4 Site Development
One of the advantages inherent in modular construction is that the site development and
building foundation are prepared while the modules are being fabricated at the manufacturing facility
and transported to the job site The site development and building construction processes happen
Permits
Design amp Engineering
Site Development
Plant Fabrication
TransportationOn-site installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
30 | P a g e
concurrently instead of sequentially like site-built construction Projects are developed on a variety of
geographic settings typical site development includes
Surveying
Demolition
Excavation
Grading
Site drainage
Foundation construction
Utility installation
There are two primary modular building foundation classifications on-grade and raised or full
foundation An on-grade foundation is generally for permanent installations and is more expensive A
full foundation can be used for temporary or permanent structures it is less expensive to install and
it is more cost effective to relocate the building later while causing minimal site disturbance
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom)
bull Step 5 Plant Fabrication
There are two scenarios for steel modular constructors There are few numbers of off-site
plant which built their own steel frames inside the plant because of high initial budget and it is
common that it would be cheaper to order the frames from another supplier and transfer to the
factory to assembly with other parts The steel frame is then loaded on the main factory production
line where the sub-floor is insulated and floor decking is assembled atop the steel frame As the
module moves down the production line framed wall sections are fabricated insulated and hoisted
in place The truss roof assembly is built in components at ground level before it is hoisted into place
The module proceeds down the line where mechanical electrical and plumbing services are installed
while the last of the insulation goes into place Interior finishes like drywall painting and flooring are
applied while doors and windows are installed
On the last stop of the production line the exterior finish and trim are applied before the
module is prepared for transportation
During construction at the manufacturing facility a third-party inspection agency is present to
ensure the modules are built in compliance with building code
bull Step 6 Transportation
The fabricated modules are shipped over the road by carriers that specialize in modular
building transportation In most US jurisdictions building shipping limitations are 16rsquo in width and
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
31 | P a g e
between 70rsquo amp 90rsquo in length per module Permissible Maximum Dimensions of Lorries in Europe and
UK for Lorry or Trailer are 4m in height 255m in width and 12m in length (International
Transportation forum)
bull Step 7 Installation
A general contractor often one specializing in modular construction will install the modules
complete any on site finish out and make the final utility connections
The choice of building foundation determines how the building will be installed Permanent
semi-permanent and on grade foundations will require the modules to be set with a crane Raised
foundations typically used for temporary buildings allow the modules to be set in place through
simple mechanical methods
With the modules in place final finish out of the interior and exterior proceeds Finish out can
include electrical and mechanical system connection between modules stairs wheelchair ramps
skirting exterior siding trim and utility connections
Literature review on possible advantages
Modular construction comes with advantages which motivates investors and innovative
constructors to apply this method on their future projects Here these benefits are being classified in
various sections such as schedule economic environmental health and safety and social-laboral
advantages
Scheduling benefits
While on-site constructors are complaining about the slow progression of construction
activities and delays on project deliveries the struggle is still to be continued to find new methods to
improve productivity and progression speed while maintaining the quality at a reasonable level
whether if its achievable or not On the other side modular construction because of numbers of
reasons is making a significant boost in term of time management in many phases As it can be seen
in figure 236 McKinsey amp Company report explains that approximately between 20 - 50
scheduling improvement can be achieved in comparison with traditional on-site construction
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method (McKinsey amp Company
2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
32 | P a g e
To be more specific literature reviews identified numbers of benefits in most of the
constructive activities from design to on-site installation As the table 22 illustrates off-site
manufacturing brings most of the time saving to the project by better coordination precise quality
management and not being affected by the on-site bad conditions Table 2 2 - Possible benefits in projects scheduling
In addition design can the ability to be applied in multiple projects instead of just one which
accelerates the project schedule significantly Various overlaps in modular construction can save lots
of time in projects such as site preparations off-site manufacturing and on-site installation with each
other
The acceleration in design process which would be ideal for schedule-critical projects (for
instance emergency accommodation for people who are affected by natural causes) also Long-lead
items can be stocked Fabrication can start and finish earlier in this case In the real state point of view
in the design phase there is one huge benefit which will be so handy when nearly ldquoshovel-readyrdquo
design documentation is needed for clients and site selectors (wwwmcminnvillebusinesscom)
The simplicity precision and clarity of the design plans in modular projects can increase the
possibility of using advanced software such as BIM which reduce the period time of designing phase
significantly With the increasing the possibility of integration of BIM in construction project
incorporating modular building technologies into project becomes more developed and
manufacturing and construction process could be streamlined (Na Lu and Thomas Korman 2010)
About 90 percent of the build activity takes place indoors which means the building process
is nearly guaranteed to stay on schedule That predictability and reliability enable you to count on
timely project completion If a skilled modular crew only spends half the time building your structure
than a site-built crew would your labour cost also gets cut in half
Because of stability of production location there are numbers of advanced technologies
which are being used in other industries production lines that can be used in these off-site facilities in
order to improve the productivity and reduce the timeline of the activities
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
33 | P a g e
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom)
The nature and outdoor construction have always mutual effects on each other mostly in a
disfavour way Site conditions often cause negative impacts on the activities which lead delays quality
insurances or stop them because of safety matters In result the project schedule can be changed and
most of the times unpredictive delays will take place in the timelines In addition there are sites which
the possibility of on-site construction for most of the year is almost zero percent or if exists would be
limited because of life risks for workforce A reasonable solution for these cases is off-site construction
which in most of them reduce the nature effects Thus factory-based production can make a
revolutionary impact on the project scheduling In modular method 60-90 of the construction work
is completed in a closed factory environment and this mitigates the impact of unfavourable weather
(FLORI MURESAN on ny-engineerscom)
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
34 | P a g e
Machinery equipment can take place in mentioned phase instead of human labour which can
boost the productivity quality as well as the time reduction Robotic assembly is one the efficient
examples of this technology One of the very first EU projects carried out in the Robotics Lab
(httproboticslabuc3mes) located at the Carlos III University named FutureHome-IF7 project The
done research was focused in the robotization and industrialisation of the final stage of the
construction process by mean of modular construction (Martinez 2008)
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes)
Economic benefits
Economic advantages can always attract investors to develop innovations Since in a project
time and cost have a direct and mutual relation with each other most of the benefits which were
mentioned earlier in the schedule section can also make positive impact in projectrsquos economy In
some cases these benefits equal to the initial costs which will be discussed later in challenges As it
was mentioned earlier the design plans can be repeated multiple times in projects because of
similarity of requirements that can save design costs in future budgets
Modular building because of their standardization and classification in design phase can be
more compatible with advanced such as BIM (building information modelling) BIM technology in its
5D phase does cost estimating material quantifications and pricing to be automatically generated
and modified while changes are applied for each building module (Na Lu and Thomas Korman 2010)
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
35 | P a g e
Foundations do not have complexity in modular buildings because of weight of the modules
which have to be manufactured lightly in order to be transported simpler to the location
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk)
Also because of the high quality and precise off-site execution there are fewer reworks in
modular products which can save costs in projects Off-site manufacturing provides more economic
benefits such as reduction of salary wages due to a smaller number of workers and more specialized
ones and adding values to each hour of work by increasing productivity to the activities
Moreover massive orders of Materials to the supplier can bring more quality to the material
multiple discounts on each offer and add more stability in prices of material in instable markets Table 2 3 - Economic benefits in modular method
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
36 | P a g e
Environmental Benefits
A highlight among the modular constructionrsquos benefits is in the environmental point of view
Since the modular buildings are friendly with environment many clients are willing to change their
method to this ecological approach in order to make their projects more sustainable and promote
their product in the market as an innovative constructor in the industry such as ldquoGrupo Consentinordquo
which not only builds modules that are available to use solar panels as energy supplier but recycle
many structural and non-structural elements and reuse them in another projects Waste management
can be applied simply in modular construction by reduction in waste during off-site production recycle
and reuses in elements in several projects use of automation can secure waste reduction at a high
rate It has been proven that modular construction can reduce waste by up to 90 thanks to off-site
construction (JAHNAVI SAJIP ny-engineerscom)
Agostinho Mendonccedila in 2018 did a research about reuse in construction industry which
shows a great improvement in terms of sustainability During 2022 FIFA World Cup in Qatar football
fans will have the opportunity to enjoy the stunning views of Doharsquos skyscrapers and be marvelled at
the unique Ras Abu Abod Stadium Its design concept results in a good cost-efficient arena with an
elegant curved square form
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images)
This innovative stadium will also allow it to be completely disassembled after the World Cup
Precisely many elements of the arena including all 40000 seats the containers and even the roof
will be reused providing valuable infrastructures to sports and non-sports projects elsewhere
Moreover off-site manufacturing can reduce emissions much more than conventional
method In 2009 Al-Hussein et al focused on the construction phase of modular and conventional
buildings and compared their CO2 equivalent emissions They analysed a 42-suite multi-family four-
story residential modular building located in Alberta Canada All the construction activities needed
for this building and a similar conventional building such as material delivery transportation
workforce trips equipment usage and winter heating were identified separately Therefore CO2
emissions from each of these activities were quantified The authorsrsquo analyses showed that modular
processes led to a 43 reduction in CO2 emissions compared to on-site processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
37 | P a g e
Table 2 4 - Environmental Benefits
While the on-site construction disturbs the sitersquos neighbourhood with noise dust congestion
and waste modular construction performs better by providing minimal project site disturbance
(Mohammad Kamali2016) Since most of the construction process takes place offsite there is less
impact on the project surroundings Modular construction reduces the number of vehicles and heavy
equipment required on site which translates into reduced pollution and less site disruption
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site (wwwcadoltocom)
Energy consumption in the occupancy phase of modular buildings dominates the other life
cycle phases This phase alone accounts for more than 70 and up to 98 of energy consumption and
consequent impacts over the life cycle of buildings while the contribution of the construction phase
is relatively small (M Kamali 2016) Sustainable material selection optimum modular factory
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
38 | P a g e
location and availability of labour which lead to less embodied energy consumption are effective
opportunities to reduce the life cycle energy consumption and the subsequent environmental
impacts In addition a smart design of insulation which is advanced in modular buildings can achieve
a high amount of energy use saving during the operation phase
Figure 2 44 - various layers of a module building unit including insulations (wwwsteelconstructioninfo)
Health and security benefits
When it comes to safety modular method can offer advantages for both phases (construction
and operation) to workers and future users Converting possibly dangerous on-site activities to an off-
site plant that there the supervision and control is much higher can reduce the accidents for the
workforces and the products It is obvious that the safety plan can be applied much more efficient in
a factory environment Not only is there a reduced risk of slips trips and falls ndash particularly as work
at height is reduced but there is also a reduction in onsite activity thus ensuring health and safety
always remains a top priority from start to finish
Furthermore if necessary factory operations can continue 247 with less risk of noise and
disruption to workers Work is also unaffected by the weather and other environmental delays which
could result in the project being turned around even quicker
On the other side during the operation phase safety can be improved for instance fire
protection can be designed by using multiple insulations and protectors inside the panels
One of the examples is Actavorsquos plan for Ensuring everyonersquos safety is at the heart of Actavo
what does and in line with this they have developed the HEART (Help Eliminate All Risks Today)
procedure Devised and implemented in the continuous effort to create an accident and incident-free
environment the HEART behavioural safety observation process sets the whole Actavo teamrsquos
expectation every injury is preventable so do not let any happen (Hannah Vickers b4edcom)
Modular construction generally achieves these requirements using fire-resistant plasterboard
conforming to BS EN 520 Alternative materials such as cement particle board and gypsum fibre board
may also be used in combination with plasterboard as the facing layer In residential construction
each dwelling usually forms a separate fire compartment All walls and floors that provide a separating
function between compartments require 60 minutes fire resistance In hotels and other residential
buildings each bedroom may form its own compartment (wwwsteelconstructioninfo)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
39 | P a g e
Figure 2 45 - Compartment floor at junction with external wall and compartment wall (wwwsteelconstructioninfo)
Social-Laboral benefits
Most of the mentioned benefits including economic scheduling environmental and safety
advantages have direct effect on social well-being as well Therefore they can also be named in this
section Future users can benefit from the quality of building energy savings etc which leads to
costumerrsquos satisfaction among the public Due to the shorter on-site schedule there are fewer
negative impacts on local businesses urban beauty image than conventional constructions Also
modular construction demands more skilled workforce and experts which can create more jobs for
these group of labour in the regions that struggle with high unemployment rates
In addition every industry needs to trust innovations in order to improve the science and help
the innovator to break limitations and explore new alternatives to solve problems Modular
construction as it was mentioned can be a great solution for the productivity problem in construction
industry and by applying these method it is possible to even find more solutions in the future which
can increase these rate more or solve other problems that nowadays are common among players of
construction industry Table 2 5 - Health and safety amp Social-Laboral advantages
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
40 | P a g e
Modular Construction role in COIVD-19 Pandemic
Recognizing the urgent need to create modular critical care units for rapidly growing numbers
of COVID-19 patients HGA Architects and Engineers partnered with Boldt Construction to design and
build a new system within a noticeably short timeframe ldquoThe initial idea was to provide rapid
response for hospitals and build a product with off-the-shelf readily available parts because we did
not know what the supply chain would be like Over the course of three weeks we went from concept
to full design and fabrication was underwayrdquo reports Ben Bruns executive vice president of Boldt
Construction in Appleton Wis (Rapid Response by Barbara Horwitz-Bennett 2020) The final product
was a prefabricated modular solution for assembling field hospitals capable of providing airborne
infection isolation rooms
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use inside convention
centres arenas and temporary structures Image courtesy of HGA and The Boldt Company (prismpubcom)
These Strategic Temporary Acuity-Adaptable Treatment (STAAT) units are isolation units with
enough clearance for safe bed transfers and accommodate equipment and a reclining chair These
multifunctional modules can be used as supplemental interior isolation rooms within an existing
system of care as a modular system connected to an existing hospitalrsquos infrastructure or as a self-
sufficient temporary hospital with its own infrastructure
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The Boldt Company
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
41 | P a g e
PCL Construction has come up with a similar solution in collaboration with Thor Plumbing and
Heating f-BLOK Architecture EH Price Industries and P4 Electrical Contractors Called ldquoQuaran-Tin
Podsrdquo the units are emergency response modular isolationcare rooms that provide temporary and
reusable emergency isolation for care and treatment of COVID-19 patients Each unit is self-contained
with built-in power heating and cooling as well as connections for medical gas oxygen and vacuum
Highly scalable and customizable the pod is continuously negatively pressurized and all the exhaust
is HEPA filtered Citizen Care Pod is a smart screening and testing pod that integrates intelligent
technology within a modular design to support a safe responsible recovery for governments
businesses and communities Customizable with the capabilities to enable full-on mobile COVID-19
testing in high-traffic environments the project will help in testing screening and eventually
vaccination on a mass scale (Christele Harrouk on archdailycom)
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction (archdailycom)
The Citizen Care Pod is a turnkey solution that accelerates recovery for businesses and public
institutions such as airports offices sports and entertainment complexes construction sites and
more by rebuilding staff and customer confidence that your organization is equipped to ensure their
safety
Unfortunately the COVID-19 pandemic is only intensifying the housing crisis Further
complicating the issue is the fact that a significant percentage of skilled labour workers will be retiring
within the next couple years which will significantly impact the construction industry As stated in
MBIrsquos ldquoThe US Construction Industry A National Crisis Loomingrdquo there are currently not enough
skilled workers to build all of the projects that need to be built in the same manner in which they have
been built in the past ldquoThere is no other choicerdquo advises Hardiman ldquoIt is now time for our
policymakers to start looking at alternative ways to build everything and we think that modular
construction should be a part of that solutionrdquo Along these lines the COVID-1 Response Page also
includes links to articles illustrating how MBI membersrsquo systems and facilities are currently being used
in housing infrastructure and COVID-19-related projects
Review on common challenges
Initial costs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
42 | P a g e
To start the modular construction method in an area there will be a significant investment
to establish a production plan and then designing team who must work alongside the execution
engineers parallelly in the design phase
factory cost Like any other industry modular construction demands a production line which
is an off-site plan with a supply chain based on 3D volumetric products First the off-site plan must be
designed based on the local requirements amount of demands availability of experts and labours and
budget that manufactures are willing to invest on this technology These factories are mostly
expensive to be build and the issue of production costs will always be a barrier to innovation in
modular construction because both the client and the architect will expect lower fabrication costs
However the art of every industrial innovative player is to study the economic pros and cons
of issued technology and then the industrial expert by doing couple trade-offs between the benefits
and disadvantages can make the decision whether to apply the new method or not Modular
construction is not an exception of this fact A local study can tell the investors if the approach would
be reasonable in all term and not only economic terms for the society or not Thus due to the
economic benefits that were mentioned earlier in numbers of regions which the labour salaries are
higher and the balance between transportation costs primary material access and costs experts
existence local market and their demand of real state and initial costs is more favourable modular
construction can be the best solution to apply On the other hand nowadays there are numbers of
region which the investors of industry are eager to use innovative method with higher costs that have
positive influence on environment and public health in which modular construction is more friendly
than the conventional method
Figure 2 49 -Balance between Initial costs and Economical benefits
First design costs and errors By changing the traditional construction products a change of
design is also demanded Modular design can be based by the production linersquos technologies the
budget of manufacturer and the final products quantity and quality In the earlier discussions about
design phase the complexity of 3D volumetric design had been mentioned and surely in the first
attempts would be expensive for the manufacturer However if the design could focus more on the
standardization of elements repetition in production line and consider integrate with modern design
software in order to provide more executive details and minimize the future errors and reworks the
rework cost can be eliminated and the design sample can be used for numbers of projects as a
catalogue with few changes Therefore by having these advantages the initial design cost can be
recovered soon and even make more benefit by the time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
43 | P a g e
Architectural challenges
One of the main group of experts who have argues about modular buildings are the
architectures who always suffer from limitations that this approach puts on their design process Most
of these challenges are mentioned below
bull Manufacturing technologies effect on the design One of the challenges which the manufacturers
can struggle is to consider a production line that be able to produce a wide range of product so
that there will be fewer limitations on the design phase This goal can often be impossible because
of the predicted budget of investors limited area of production plant and lack of technologies
Thus it is the architect who must be flexible with the production line and its boundaries
Moreover it is the art of the architect which can maintain a balance between ability of production
line and attractivity and innovation of the final product for the market and the industry
bull Transportation boundaries on architecture It is a fact that the transportation of modular
construction have puts limitations on the architectrsquos works The modules must obey the
obligations and regulations of the region that want to be transported in Therefore architects
must design modules which are transportable and minimize negative economic and timing effects
for the project In addition in the designing process environmental aspects which can be
happening during the transportation phase must be considered
bull Regional architecture specializations There are cases in which an off-site production plant ships
same model of modules for numbers of projects which are going to be assembled in variety of
regions with different climate cultural architecture and local construction regulations which can
surely have negative effects on the regionrsquos construction industry real estate market and cultural
architecture aspects For instance the harmony of the angel of sunlight and the windows
formation and dimensions in a residential building located in eastern region and western ones
which reduce or increase the sunlight absorption inside the building for the residents In this case
if the same form of modules will be transported and assembled without of any changes the
unsatisfaction of future users can be increased and in a result the demands can be reduce
significantly which could cause a failure for the real estate and construction industry of the region
In terms of architectural culture modular manufacturers must consider the traditional
architecture of the location in the designs in order to make sure that the harmony will be kept
among the present buildings and modular ones
bull Lack of knowledge about modular buildings among architects Manufacturers argue about the
lack of enough knowledge of architects about the modular fabrication process The third-party
inspections and approval process Transportation methods and its boundaries Onsite assembly
procedures The cross section of a modular structure which can reduce their understandings from
manufacturerrsquos demands of project and result a unsuitable design for the final products These
disagreements come with every innovation in civil engineering society which architect must follow
their lead most of the time The solution for this cause is to educate the architects by planning
workshops by the manufacturers or internships during a project so that architects can improve
their knowledge and gain actual experiences by observe and participating in real projects
bull Unfeasible on-site finishing Common architectural innovative designs focus a lot on finishing
works in order to gain attentions of buyer and improve attractiveness of buildings There are
different views about this subject Some manufacturers think that the finishing process must be
as simple as possible or minimize the schedule and costs on-site to benefit from the project On
the other hand architects believe that the modular buildings are not attractive enough because
of repetition in their design and try to focus on finishing process to make them desirable to the
market or improve the products in architectonic point of view
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
44 | P a g e
Transportation challenges
By transferring most of the construction activity to the off-site plant transportation plays a
vital role in the projects so that in case of poor logistic management can damage numbers of benefits
which were achieved in the factory plant
bull Dimensional and weight barriers based on type of transportation The type and technologies of
every modular constructorrsquos logistics can affect the project from the design phase to the on-site
assembly These effects can change the dimensions weight and structural features of the product
For instance modular structures transported on a flatback trailer will be limited in length width
and weight based on the physical capacity of the truck Components fit into shipping containers
are best suited for projects overseas because the structural integrity of the containers allows for
unorganized stacking However components will be limited by the interior dimensions of the
container in length width and height (Joseph M Schoenborn 2012)
bull Long distance transportation and lack of existence of local factory Off-site plants are not
available for every site location in numbers of states or even regions yet because of poor
development of these method in those regions Therefore in some cases the modules must
shipped even overseas to the site location to be assembled Long distance and its possible
difficulties during ground or marine transportation can bring extra costs for the project which
must be studied economically before the biding process
bull State regulations on structures dimensions and strategic issues Estate laws can always put
boundaries on construction industry and modular constructors are not an exception Every region
has its structural and transportation regulation which limits the final product In addition estate
approval during transportation phase can harm the projectrsquos scheduling program and put delays
on the arrivals or even occasional penalties which causes extra costs in the budget
bull Negative effects from environment on the modules during the transportation While the
modules are being transported to the site these products are in direct exposure to the
environment such as sunlight rain wind and other natural causes By the time possible damages
can be appeared in the modules which in some cases can be too critical that module need to be
repaired or replaced to be used On the other hand ground transportations can cause vibrations
on the trucks and its loads and the intensity of damage generally increases with the roughness of
the road surface which in some creates cracks or more critical damages on the structural element
installations or finishing The solution is to use To minimise transportation difficulties the vehicle
having vibration absorber can be used to minimise damage due to vibration and additional
precautions need to be considered for wider modules while low bed transport vehicles are
preferable for transporting taller modules (W Ferdows 2019) Moreover loading and offloading
processes must be carefully done by precise strategy and adequate equipment in order to avoid
the harms on the products
bull Transportable materials There are two terms which force modular constructors to use advanced
and high-quality materials transportation and design situations Transportation as it mentioned
earlier puts limitations on the final product and force the constructors to use material which have
less weight more against resistance road vibrations and endurance against sunlight and humidity
exposures In one word these materials must be part of a final product which can be
transportable Often these materials add costs on the project because they are more expensive
than the ones which have been used in conventional buildings All properties need to be
structurally sound in situ but units built using offsite construction methods also need to be
structurally sound whilst being raised and lowered throughout the transportation and assembly
stages of the process Key structural elements such as beams columns and potentially walls and
floors must be repeated in three-dimensional modules for transportation purposes This can
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
45 | P a g e
significantly increase material costs depending on the material choice and level of design
optimization (McKinsey amp Company 2019)
On the other hand numerous benefits which modular construction has in terms of material
such as less reworks discount on massive offers no exposure to natural causes and its off-site storage
and less waste during the production can assure the constructors that these challenges can overcome
the fact that modular buildings work better than conventional ones in a material criteria
Wrong perceptions among public and real estate market
Innovation without correct publicity brings wrong perception among people and markets
Also errors bad experiences of users and unprofessional works can change the mindsets quickly by
unsatisfying the users and in result investors During a period in past off-site accommodations were
mostly for temporary uses with low quality material and less functional features The demands of
permanent housing raised after a break such as world wars for those who lost their houses and
refugees that wanted to live abroad Therefore numbers of companies started to modify their off-site
products in order to have more lifetime and serviceability However there were constructors who
could not provide buildings with better functional services and the users became unsatisfied and lost
their trust in these products This wrong perception had been raised even until now that off-site
building such as modular ones will not serve a long lifetime and have low quality material incommode
and unattractive design and a poor functionality Obliviously bad perception of people will reduce the
demands and destroys the market as well
Today the industry recognizes the need for durable construction for even temporary uses
making it possible to move and re-use full buildings So a lack of knowledge among consumers as to
what is possible can prevent design innovation In order to overcome the stigma sometimes associated
with modular construction manufacturers attempt to offer a built product indistinguishable from one
built onsite Therefore the industry advertises a direct alternative to onsite construction In a
comparative analysis of the two processes time savings and worker safety stand out as the primary
advantages of modular construction over onsite construction The building manufacturing process
itself construction in a controlled environment with access to advanced technology is an evolution
of the art of building which is traditionally slow to evolve The modular building industry therefore
should advertise a different building product altogether featuring design innovation and ingenuity
executed through advanced building techniques (Joseph M Schoenborn 2012)
Moreover in order to raise the demands among the public who can be future users a range
of positive publicity about the environmental advantages such as less emission economic savings like
less energy bills cheaper and easier maintenance processes during the operation phase and faster
construction process which help them to be accommodate sooner can create a positive mindset
among the public In addition post-sell services from constructors such as better assurance policies
for buyers maintenance services and offering loans to customers who are in emergency
accommodation needs can change the market significantly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
46 | P a g e
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects (casasinhauscom)
Integration of advanced software
As it mentioned before modular construction can benefit from using innovative software in
their designing phase in order to be more precise on planning and provide detail for the production
line One of these software programs is BIM which can be used in design construction phase on-site
assemble and even operation phase However despite its advantages there will be some challenges
as well The greatest challenge of using BIM in construction project is the implementation process
itself regardless of the software capabilities Development of accurate BIM model requires extensive
resources and in-depth knowledge of construction methods and process Most small or medium firm
could not afford the special team and man hours to aligning BIM (Na Lu and Thomas Korman 2010)
Other than finance and organizational issues the project team has experienced legal challenges as
well The use of BIM technology encourages multi-disciplinary collaboration which contrasts to
defining responsibility to each party and then assigning liability issues among the parties In addition
using BIM models instead of traditional contract documents raises questions on insurance coverage
and confidentiality exposure Ownership and control of the model use and distribution of the model
and intellectual property rights are some of the issues that need to be addressed while BIM
implementation being adopted in construction industry
Redefining the contracts
Due to the changes over the responsibilities of every participants the amount of their
influence on projectrsquos activities and transferring most of the work to the off-site plant a new way to
contracting is needed in order to optimize the relationship between the owner designers and
manufacturers during all phases of the project Here are some of the common types of contracts which
are being used among modular building industry
bull Design-build The architect modular manufacturer and onsite general contractor are
hired as a team and assume the responsibilities of design and construction together DB contract can
be named one of most traditional types of contracts that would create an integration between all the
parties of a project Due to the design-build nature of modular construction a close partnership is
demanding during the project phases
bull Design-bid-build After the architectrsquos design has been approved by the client a
competitive bidding process takes place This results in a greater disconnect between parties The
common gap between participate happen a lot in this type of contract which frequently can cause
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
47 | P a g e
misunderstandings about responsibilities of each expert incomplete information about the project
design or executive details and lack of transparency among the participants
bull Negotiated bid The modular manufacturer is hired first by the client to find the
appropriate architect and onsite general contractor that can be hired within the constraints of a
budget This concept may increase bonding between experts and improve everyonersquos understandings
about many aspects of the project But the budget will decide whether the quality level design
enhancement can meet the clientrsquos requirements or not In addition in case of clientrsquos approval the
question would be the future userrsquos satisfaction can be achieved or not due to the budget limitations
on the project quality level
bull Certified Modular Architect (CMA) A sustained relationship between an architect
and a manufacturer can be developed over multiple projects Therefore a certification process
providing training and continuing education can be introduced to the modular building industry An
architect intimately familiar with modular construction is best suited to handle coordination issues
that arise when work is being done in the factory and onsite simultaneously A it mentioned earlier
architects understanding and knowledges is critical to avoid possible mistakes and unsuitable designs
for modules Therefore this certified education which can be called as a semi-professional internship
for the design team in order to be present at every phase of the project
Supply chain-transportation-onsite assembly management errors
One of the main objectives to use prefabricated elements in construction is to raise the
productivity in execution phase which is mostly happens in off-site plant As it mentioned before there
is a supply chain in manufacturing plant and its productivity is depended to many key factors which
will happen outside of the factory Continuity of assembly operation is one of them which would be
happening in parallel with off-site supply chain After the modules were prepared to be transported
to the site the transportation system must be synchronized with the factory delivery and assembly
demands If any delays may happen during the transportation would affect the both origin and
destination scheduling storage policies and demands
On the other hand assembly line also must on-time and well-communicated with off-site
plant experts because any changes in execution phase can make huge negative impacts on supply
chain productivity Therefore these three important phases must plan based by on-site demands
supply chain productivity execution management and transportation systems
Figure 2 51 - synchronization between supply chain transportation and on-site assembly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
48 | P a g e
3 Common challenges in modular construction industry by a
survey Methodology
Objective
This study used qualitative research and specifically a grounded theory methodology to
uncover more information about advantages of modular construction and its constraints or barriers
to develop this method in the market Qualitative research emphasizes the influence of the researcher
on the data collected
Role of the researcher
In this study I acted as the sole researcher who was responsible to design questions based by
literature reviews and then by creating an online survey form try to collect the data from the
participants
Ethical considerations
To protect the rights and guarantee the safety of participantrsquos information following actions
were done
1) The research objective and process were made clear to the participants
2) The collected data was used for research objectives only
3) Only eligible participants who are modular constructors and manufacturers were
chosen for this survey
4) The access option to the survey information gave to the participants after the
research was finished
5) The anonymity of the participants was maintained
6) The name of the participant and their brand was remained confidential for all roles
even the researcher to obey the law of data protection
Survey setting
Due to the emergency restrictions which caused by a virus pandemic across the world several
options were unavailable to be done such as face to face interviews factory visits and project site
practices Therefore online interview was the only solution which can be happen without any danger
for participants and researcher In most regions construction companies are suffering from a full shut
down on their production line and on-site projects so that access to these participants became even
harder than usual Thus an online survey form by office forms was chosen for this research so that
the participants can answer the form questions at any time and location with ease to answer by
multiple accesses to the formrsquos link (Figure 31)
This survey forms had been sent by email to the official addresses that were mentioned in
their websites for contact The priority in choosing the recipients were the construction managers
project managers and executive engineers so that the information will be collected from the operation
managers who have the most technical experience and have the most knowledge with construction
phases from off-site production to on-site installation This could also help the survey to find the
challenges during the construction that were not able to be visited due to the restrictions of global
pandemic
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
49 | P a g e
Figure 3 1 - Online office forms for survey use
The estimated time was reduced to 13min with the most important questions to improve the
efficiency and be timely reasonable for the participants
Development of questionnaire
After hours of study on numbers of articles which have focused on challenges in modular
construction industry several were found that have lack of scientific scope and recommended
solutions Therefore many of the questions were designed to first shed a light on the potential
advantages which have not been mentioned specific and completely unknown for the industry For
instance the social benefits which came immensely useful during the COVID-19 pandemic for health
centres and medical infrastructure etc Moreover a lack of inconsistency between industry and
science came to notice which shown a massive gap between these two important roles in construction
industry This gap explains that the scientific researchers in some areas have the minimum contact
with industrial players in construction world in comparison with other industries which the opposite
situation is applied To fill this gap questions were designed in a way which have an origin of scientific
researches and direct and first-hand information from the construction industry players which are
constructors modules manufacturers etc
Development path of questions can be explained as critical path to the best details of each
criteria than can obtain useful information from participants In terms of advantages the benefits
which were identified from literatures were ordered and asked form participants to be confirmed and
validated by the industry players in real project cases For instance in an environmental point of view
Reduction in Energy Consumption was identified in literatures and had been asked among participants
to confirm the hypothesis that modular construction can reduce the energy consumption in
comparison with traditional methods (Figure 32)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
50 | P a g e
Figure 3 2 - Questionnaire development
Participant profile
Experience amp professions
As the ldquoTable 31rdquo explains information from five companies have been selected for this
survey with variety of backgrounds from pioneers to well-experienced players in industry with over
than 120 years of experience in the modular construction society as constructors and modular
manufacturers The experts who answered have different roles in the industry from CEO to architect
and sales managers so that the data can have more perspectives of views on the questions such as
sales market and design process to project management Table 3 1 - Participantrsquos profiles
Because of diversity in the influence of challenges between massive international builders and
local players these five companies responds have been compared to each other from company C
which is a local constructor to company E that is currently executing modular projects in 80 countries
with approximately 6000 modules build annually
Types of materials in some cases can have different statistics in results For instance in
modular construction which steel and wood modules are more often used in projects can produce
various amount of CO2 emissions and waste or recycle process can be done with more ease For that
reason these survey all types of materials are considered including steel modules concrete modules
and wood modules There is also an argue that some benefits and challenges cannot be seen in unique
projects with more repetition in production of elements and mass production such as hotels and
schools while in residential projects can exists more than the others To cover all the contrasts of
60 of participants
can acheive a 30-40
reduction energy
consumption
A Our homes are not positive from an energy
perspective
B We can finish a 4 months traditional project in 8-10 weeks and Energy consumption of a factory is known and relatively constant on a weekly
E 30 reduction in energy consumption
Modular construction can
reduce the energy consumption up
to 30 in compariosn with
conventional methods
QsCompany A B C D E
Years of company experience 10-15 10-15 20-30 20-30 30-50
Position of participant CEO Sales Manager Design Architect Quantity Surveyor Foreign Trade Manager
Professional experience 15 13 30 NA 3
No of employeesfactoryModules build annually 801200 1301490 151- 50280 25026000
Type of material(WoodSteelConcrete) W amp S W W W S amp Conter amp fiber cabins
Types of Projects (ResedentialSchoolsHospitalCommercial) R R amp S amp C R R amp S amp C amp H R amp S amp C amp H
Use of BIM Yes No No No No
Level of automation 20 reaching up to 80 20 Off-site 60 On-site 20 20 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
51 | P a g e
information these companies have been selected that are involved in all types of modular building
projects including residential hospitals schools and commercials buildings
As it mentioned before BIM program can advance the projects in many ways however
unfortunately among these participants only company A is able to benefit from this software from 0
to 100 of the project Therefore the further arranged interview focused on BIM Function was
cancelled and may be done in the future investigations
Automation can play an important role in improving the productivity and sustainability of
construction processes as a part of ldquoindustrialization in constructionrdquo movement Among survey
participants the minimum automation level in off-site plants is 20 and maximum of 60 and in on-site
activities can be up to 40 In addition company A claimed that in near future their automation can
reach up to 80 which is an innovative move in construction industry On the other hand company
with over than 6000 modules build annually have a significant 60 of automation in their plant which
shown a massive interest of investment on this technology In addition automation application
difficulty have direct relation with the type of materials used in modules and type of the projects which
as Table 31 illustrates company E with the most variety in project types and materials use have
achieved a huge success in application of automation with a level of 60 which also helped a lot to
expand their market overseas
Data collection
General information
All the received information has been attached in ldquoAnnex 1rdquo where the responds are not
edited and mentioned in the original shape Here are the shorter versions of responds
bull Motivations to choose modular construction over traditional
To bring the attention of investors to an innovative method reasonable motivations are
needed which can be the current demands of market economic profits and environmental benefits
Therefore it was necessary to identify the motivations of these companies to start a modular
construction form Economic advantage for most of these has a priority not just for being profitable
but for being able to develop their dominance in the future On the other hand innovation has an
approximately same amount of interest which explain the reason behind choosing modular method
that is one of the most innovative off-site construction methods in the industry
The fact that mentioned before in literature reviews high demands in the market and the lack
of provide by construction players is one of most important reasons to apply a fast and high-quality
solution for reach the satisfaction of housing market Shorter schedule and environmental benefits
took the next places of priority in motivations for these companies which are also important for sure
Figure 3 3 - Participants motivations to start a modular company
28
9
18
18
27
Economic benefits
Enviromental benefits
Shorter schedule due to the need
High demands of housing in themarket and lack of provide
Innovation
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52 | P a g e
bull Built in factory panelssubcontracted panels used in modules
All five companies are manufacturing the panels that used in modules by their own inside the
off-site plant which as it mentioned earlier the selected participants have a variety of production rates
and by this information that they are able build their own panels it can be said that their production
is 100 off-site However in the case of company E which is a massive international modular player
there are some types of modules that are being provided from domestic market because of economic
feasibility issues
Economic issues
bull No of labourLess wages of salaryAdded value in each hour of workneed of
special workforce
Generally the participants mentioned that there fewer number of workers are needed on and
off site in comparison with traditional method About the amount of salary wages company A
confirms that for each hour of work off-site less amount wages are being paid to workers On the other
hand the shorter schedule of projects in modular projects can reduce the payments as well The fact
that most of the participants are emphasizing is that the efficiency of work and added value of
activities off-site are much more than the on-site traditional projects where company A acclaimed
that in terms of efficiency ldquo1 hour in the factory is equal to 4 hours on-siterdquo
Environmental status
bull Life cycle duration of products and material recycle
Company B acclaimed that they do have multiple solutions for each materials that theyrsquore
using in their modules for instance the unusable drywalls and PVC materials which they send for
recycling or the woods that would use into mulch products or for heating by others
Company E told that their products have a 50 years life span which is the same as a lifetime of
traditional build residential house However company C have some difficulties in recycle and reuse of
their elements because of unportable feature of their products
bull Integration the modules with other innovative technologies
Four of these five companies confirmed that their products have the option to integrate with
other innovative technologies such as self-powered homes by solar panels and also using advanced
insulation technics made by non-petroleum materials in their panels to reduce the energy
consumption during operation phase
bull Waste reduction
Company A acclaimed that their production line generates significant amount of 70 less
waste in comparison with traditional method The rest of the companies focused on carbon footprint
reduction and were able to reduce it 15 less that traditional method by choosing environmentally
friendly technologies in production and wise choice of materials for their products
bull Reuse of structural and non-structural elements in projects
Three of five participants confirmed that they have the ability to re-use their products in the
next projects in order to reduce the waste and energy consumption during the manufacturing
processes Type of the projects and material have the direct relation with the potential of reusability
in elements and due to the variety that the participant have in both criterions the potential is variable
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
53 | P a g e
Figure 3 4 - Re-use potential
bull Reduction in Energy Consumption
Company E mentions that modular construction can achieve a 30 of energy saving in
comparison with traditional site-build method while company A acclaimed that their homes are not
positive from an energy perspective Company B gave more details on energy consumption by making
a comparison between off-site activities and on-site traditional construction and acclaimed that due
to the shorter schedules in off-site production energy consumptions can be reduced up to 50 They
mentioned that ldquoEnergy consumption of a factory is known and relatively constant on a weekly
monthly and annual basis A competent and experienced modular builder can many times finish the
entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-
built house could require as much as 4 months for the same completionrdquo
Social Benefits
bull Delivery of projects for emergency services during COVID-19 Period
As it mentioned earlier due to the virus pandemic that is happening at moment in all around
the world a rapid response is needed more than ever for emergency services for health organizations
and according to this survey one of these companies is providing products for this cause which can be
a good news and accounted as a social benefits for this method of construction
Figure 3 5 - Contribution in Covid19 epidemic
bull Providing post-sale services for clients
In contrast with conventional construction which just have the responsibility until the delivery
of the project modular constructors because of their industrial profile have the ability to offer post-
No40
Yes60
Reuse the structuralnon-structural elements projects
No
Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
54 | P a g e
sale services to the clients such maintenances upgrades etc due to the results of this survey four of
these five companies confirmed the availability of post-sale services for their clients
Figure 3 6 - Post sale services por future clients
Initial costs
bull Initial investment and its Payback period
Company A claims that their initial investment to establish their company was about 20 million
Canadian dollar and its payback period was 5 years Company E had the amount of 15 million USD with
the same 5 years period However company C like many of the older players in modular construction
industry who started way earlier cannot estimate their initial investment
bull Factors that can change the initial costs
There are factors which can make a change in initial costs of companies The participants
prioritized these 6 chosen factors starting with product types and production range with 31 of
importance among others Level of automation took 25 share of the pie chart which has direct
relation with the initial costs Off-site plantrsquos location has 19 of efficiency on starting costs and
furthermore the quantity of sub-contracted players in the projects achieved 13 of the graph Finally
financing and design enhancement have the minimum equal shares of 6 which despite of being the
last factors have the efficiency on initial costs as well
Figure 3 7 - effective factors in initial investments for start-up companies
6
25
31
13
19
6
Factors that effect on initial costs
Design enhancment Level of automation
Product types and production range Less sub-contracted
site location Financing
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
55 | P a g e
Design limitations
bull Design boundaries caused by production line
Company A mentioned the subassemblies as the main element to be considered in design
phase while company D and company B introduce a maximum dimension for their production lines to
be economically viable for transportation costs In addition to those company C and company E
confirmed that there are no boundaries for the designer caused by the production lines because of
their wise choice of prefabrication methods
bull Lack of knowledge from architectsdesign engineers about production processes
transportation limitations etc
One of the main problems of start-up companies and the experts who join the modular
construction industry is the lack of knowledge about off-site processes and transportation limits
Three of five participants confirmed that there is lack of knowledge in these area from designers
Figure 3 8 - Lack of knowledge among designers and engineers
Transportation Limitations
bull Transportation regulation effects on modular projects
Three of five participants confirmed that the regulation by transport administrative can be
harmful for the projects such as extra costs or time delays on schedule Company A mentioned the
time delays in giving permits to the manufacturers and constructors which can damage the
synchronization between production line and on-site installation by reducing the speed of
transportation of elements to the site Company B added information about transportation system of
some states in America which use the term ldquoSuper Loadsrdquo to put limits on oversized shipping that
increases the cost and time on the project On the other side Company C as a strategy to avoid this
problem used legal load limits in their design instructions so that their products will obey the
regulations
bull Transportation boundaries on material choice and project costs
Company B D and E confirmed that the terms of special transportable material will not add
extra costs on the project Company A acclaimed that the extra costs by transportation can be offset
by speed of production and reduced financing costs for the project
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
56 | P a g e
Project management challenges
bull Difficulties in using automation in off-site production
In this survey based on literature reviews 4 main reasons for difficulties of using automation
in off-site production were selected to ask the participants Integration with advanced software and
high expenses of application in production line took approximately 60 of importance among others
Codding problem is another major problem in this subject which have 28 of pie chart In addition
company A demanded ldquoAn international coddingrdquo as a solution for this problem The last section
belongs to ldquolower salaries of manual processesrdquo which has the minimum importance of 14 among
participants
Figure 3 9 - challenges of using automation in off-site plants
bull Contracting problems
Starting with company A which acclaims that every state has its own code and the lack of a
universal code can bring challenges for modular players
Company B explained about the misunderstanding by final client who is the end home buyer
who ldquobelieves the factory to be the builder and the actual independent builder to be a sales agent
for the factoryrdquo Their recommended solution for this problem is to define the relationship between
the participants of projects their responsibilities by social media and requiring the builders customer
to sign a disclosure acknowledgement from that describes the relationship in detail
Company C mentioned a financial challenge caused by the banks in the projects that are
financed by them (Banks) which do not consider the project done until erected on-site This issue
creates pressure on cash flow of project where bank finance is involved The only problem that
company E consider in terms of contracts is lack of timing on project delivery which is generally causes
by constructors or general contractors
bull Lack of synchronization between projectrsquos participants
To begin with company A believes that there is a lack of quality partners on site They explain
that the problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution Company B mentioned that the responsibility of ensuring
28
29
29
14
Difficulties in using automation in off-site production
Codding Integration with advanced software Cost Lower salaries of manual processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
57 | P a g e
that the work is done properly belongs to the builder which any ldquodelays in this can result in postponed
transport of product and interest through demurrage charges
bull Sub-contractor for site planning and foundation phase
Company A uses local subcontractors for their site planning and foundation phases because
of variety of locations of their projects and ease of using local subcontractors Company B have only
the responsibility of modules production and defines the customer (the general
contractorindependent builder) responsibility to execute rest of the project phases have sub-
contractors if needed Company C does have sub-contractors for site-preparations and foundation
phases under direct supervision and the reason to not performing by their own is the high costs of
required equipment and not being portable for each project
bull Technology gap between sub-contractor and modular constructor
The only issue that were mentioned by participant is where company A recommended to ldquoto
educate most local subs on our process and reason for doing things a certain wayrdquo
Company B and C acclaimed that there are no challenges for the off-site production
Social challenges
bull Wrong perceptions among public and market
The only value that the market considers choosing modular method over traditional
construction is to be cheaper Company A says
According to company B experience in USA majority of people the media and even
professional engineers do not understand the capabilities of modular construction Many people
continue to confuse this form of construction with HUD on frame products
Another wrong perception that the publicmarket believes is that the prefabrication methods
limits the design options while Company C believe confirms that the reverse is the case
bull Solutions for resolving the wrong perceptions
Company A believes by using one of the main advantages of modular construction which is
shorter schedule the market can be dominated by modular projects and the more cases they deliver
the more recognised this method would be among the public and at the end the superior nature of
modular approach can be proved Company B addresses a solution in a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Company C acclaimed that advertising the modular advantages
among the public would be enough
Data analysis amp conclusions
The data from this survey can be used as an input data and prioritizations for the next chapter
which is decision-making process between four alternatives The solutions and recommendation will
be repeated at the recommendations at the final chapter as well Here are the conclusions about
advantages and challenges in modular construction mentioned by professional participants
Advantages
Economic benefits Generally apart from the other benefits as the participants mentioned
that there fewer number of workers are needed on and off site in comparison with traditional method
and Due to the shorter schedule of projects in modular projects can reduce the payments wages
Other fact that most of the participants are emphasizing is that the efficiency of work and added value
of activities off-site are much more than the on-site traditional projects
Environmental benefits Due to the variety of solutions for each material that they are using
in their modules there is high potential to send the used elements for recycling or would use into
mulch products A long lifetime span is acclaimed for the products which is close to the traditional
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
58 | P a g e
ones Majority of participants confirmed the literature concept that their products have the option to
integrate with other innovative technologies such as self-powered homes by solar panels and also
using advanced insulation technics made by non-petroleum materials in their panels to reduce the
energy consumption during operation phase In the waste management term there is a possibility for
production lines to generate significant amount of 70 less waste in comparison with traditional
method Moreover about carbon footprint reduction there is ability to reduce it 15 less that
traditional method by choosing environmentally friendly technologies in production and wise choice
of materials for products While there is argue that modular construction can achieve a 30 of energy
saving in comparison with traditional site-build method there are claims that their homes are not
positive from an energy perspective However this idea mentioned that by making a comparison
between off-site activities and on-site traditional construction due to the shorter schedules in off-site
production energy consumptions can be reduced up to 50
Social benefits As it was mentioned in literature reviews there are social benefits in modular
construction that can improve the satisfaction of clients Post-sale services for customers are possible
which is completely opposite to the traditional projectrsquos conditions
Challenges discussion
Initial costs It is obvious that a high amount of investment is needed to stablish an off-site
plant to start prefabrication of construction elements but the payback period is not that long that put
boundaries for start-up future players due to the collected information There are factors which can
make a change in initial costs of companies that are prioritized by the participants starting with
product types and production range level of automation which has direct relation with the initial
costs Off-site plantrsquos location the quantity of sub-contracted players in the projects and finally
financing and design enhancement have the minimum equal shares
Financial aids Financial assists which are crucial for kind of projects that are dependent to
these aids are not harmonized with modular project processes where there are argues that until the
first deliveries of elements to the site location and their assembly these aids are not reachable This
issue creates pressure on cash flow of project where bank finance is involved Changes in contract
conditions and education for financial supporters are recommended solutions to improve the
partnerships in projects
Design boundaries it was mentioned the subassemblies as the main element to be
considered in design phase while some players introduce a maximum dimension for their production
lines to be economically viable for transportation costs However there a possibility to eliminate the
boundaries for the designer by the production lines because by wise choice of prefabrication product
types
Lack of education The idea of lack of education among engineers and architects about off-
site construction methods was proved by the collected information which have to be resolved by
updating the education resources to innovative methods that can improve the productivity rates and
sustainability
Transportation regulations negative effects it is confirmed that the regulation by transport
administrative can be harmful for the projects such as extra costs or time delays on schedule Time
delays in giving permits to the manufacturers and constructors which can damage the synchronization
between production line and on-site installation by reducing the speed of transportation of elements
to the site A strategy to avoid this problem used legal load limits in their design instructions so that
their products will obey the regulations
Choice of transportable material effect In contrast with literature review which mentioned
the idea of extra costs by choices of transportable material this survey confirmed that the term of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
59 | P a g e
special transportable material will not add extra costs on the project Moreover the extra costs by
transportation can be offset by speed of production and reduced financing costs for the project
Automation use challenges Integration with advanced software and high expenses of
application in production line took approximately 60 of importance among others Codding problem
is another major problem in this subject In addition ldquoAn international coddingrdquo was mentioned as a
solution for this problem Every state has its own code and the lack of a universal code can bring
challenges for modular players ldquolower salaries of manual processesrdquo has the minimum importance
Defining responsibilities boundaries There is a misunderstanding by final client who is the
end home buyer who ldquobelieves the factory to be the builder and the actual independent builder to
be a sales agent for the factoryrdquo Their recommended solution for this problem is to define the
relationship between the participants of projects their responsibilities and requiring the builders
customer to sign a disclosure acknowledgement from that describes the relationship in detail
Lack of partnership among projectrsquos participants There is a lack of quality partners on site
The problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution The professionals answered that the responsibility of
ensuring that the work is done properly belongs to the builder which any ldquodelays in this can result in
postponed transport of product and interest through demurrage chargesrdquo
Wrong perception of publicmarket The only value that the market considers choosing
modular method over traditional construction is to be cheaper while majority of people the media
and even professional engineers do not understand the capabilities of modular construction Many
people continue to confuse this form of construction with HUD on frame products Another wrong
perception that the publicmarket believes is that the prefabrication methods limits the design
options while some players believe that the reverse is the case Therefore by using one of the main
advantages of modular construction which is shorter schedule the market can be dominated by
modular projects and the more cases they deliver the more recognised this method would be among
the public and at the end the superior nature of modular approach can be proved Another solution is
a form of cooperation between builders manufacturers architects and engineers to educate the
public by national entities such as Modular Home Builders Association
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
60 | P a g e
4 Decision making based on potential advantages among three
modular alternatives and conventional construction method in a
project by MIVES software Methodology
Objective
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria potential benefits can be recognised However to find out how much practical these benefits
are in the market several trade-offs must be done by professional tools such as project management
software programs which can take decisions based on the input data that receive
The objective of these thesis is to examine the practicality of modular construction by taking
the best decision among 4 alternatives including a conventional armed concrete building with steel
modular concrete modular and timber modular methods and see that the mentioned advantages can
lead the methods to become the best option to choose for building the project as a project
management point of view
What is MIVES
In order to make the most sustainable and reasonable decision among the alternatives a multi-
criteria decision-making program was used called ldquoMIVESrdquo MIVES is the acronym for Modelo
Integrado de Valor para una Evaluacioacuten Sostenible which means Integrated Value Model for a
Sustainable Assessment It is a multi-criteria methodology for decision making It allows transferring
the different characteristics of the objects to be evaluated to a series of homogeneous and
quantifiable parameters which facilitate the objectification of the choice
The MIVES methodology consists of creating a model that defines all the characteristic
features of the elements to be evaluated assigning them a function that allows converting the
different peculiarities of the alternatives into a common unit which we will call value Once the
amount of value for each alternative is obtained it can be used for a sustainable evaluation
(wwwdecaupcedu)
Data collection process
Case Study references
bull Journal of Cleaner Production (WAHammad 2019)
(httpsdoiorg101016jjclepro201904150)
This Fabolous multi-criteria comparison was done between two methods of conventional and
steel modular building in two cases case A which is a normal residential building and case B a school
building to measure the sustainability level of them in economic environmental and social areas The
location of this was considered in Sydney and central coast Australia and four BIM models had been
designed for each alternative in both cases The total floor area of Case A is 63 m2 (87m x 72m)
When adopting modular construction the granny flat is designed from 2 modules each module is
36m x 87m Case A was chosen as the study case to focus on because of type of the project that is
residential building
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
61 | P a g e
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study (WAHammad 2019)
The purpose of this journal is to add sustainability criteria as main factors for constructors to
make a multi-dimension decision whether to use Modular construction for a project or continue with
conventional methods
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and conventional methods
(Akbarnezhad 2019)
bull A comparative life cycle assessment (LCA) of concrete and steel-prefabricated
prefinished volumetric construction structures in Malaysia (Ali Tighnavard
Balasbaneh 2020)
(httpsdoiorg101007s11356-020-10141-3)
This researchrsquos focus is to compare two types of volumetric modules function in terms of cost
and LCA factors such as Greenhouse emission etc on a residential project with the approximate area
of 105m2 located in Malaysia based on local regulations Prefabricated Concrete Modules (PCM) and
Prefabricated Steel Modules (PSM) were considered for this project Recently Malaysian
administrative system has been pushing the companies and researchers to investigate on these types
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
62 | P a g e
of construction methods in order to measure the benefits and obstacles of using them in future project
and try to resolve the productivity problem in construction industry The construction industry in
Malaysia has been labelled ldquounproductiverdquo for its reliance on a large labour force and its use of non-
prefabricated strategies at a proper scale (Balasbaneh 2020)
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020)
bull Modular vs Conventional Construction A Multi-Criteria Framework Approach
published at ISARC 2017 (AWA Hammada and A Akbarnezhad 2017)
This paper did a comparative analysis in cost time and carbon emissions by BIM models
Material and equipment libraries and existent databases on a project in the North-West of Sydney
involves the construction of a granny flat with dimensions 14 m by 16 m
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017)
The framework of this papers based on the BIM model analysis with input data project actual
projectrsquos budget material and equipment used in the construction and environmental information in
database and then a comparative study on emissions during constructionmanufacturing schedule
and costs of project for crew material and equipment (Figure 45)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
63 | P a g e
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad 2017)
bull Life cycle greenhouse gas emissions and energy analysis of prefabricated reusable
building modules published on Energy and Building (Lu Aye 2011)
(httpsdoiorg101016jenbuild201111049)
Aye and his team did a LCA study on three alternatives PSM PCM and PTM which were used
in a multi-residential building with 63 apartment units with area of 63 m2
Figure 4 6 - Architectural section of multi-residential building (Aye 2011)
The modules in this study were categorized in 4 main elements Exterior walls with insulation
panels Interior walls used for internal separation which mostly build with timber frames and plaster
boards Floors with plywood material on topping in all alternatives and ceilings with thick plaster
boards and steel concrete and timber parts as main elements (Figure 47)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
64 | P a g e
Figure 4 7 - Structural elements used in modules (Aye 2011)
bull Comparing Environmental Impacts of Building Modular and Conventional Homes in
the United States published at Construction Matters (John Quale 2012)
(httpsdoiorg101111j1530-9290201100424x)
Quale did also a comparative analysis focused on Environmental emissions on two PTM and
Conventional Timber building Three residential modular companies generally representative of the
eastern US modular industry supplied data on completed projects for this study including utility
bills worker commuting information building materials and waste procedures construction
schedules employee schedules and other relevant information (Quale 2012) 186 m2 two-story
home that is a model for one of the companies involved in the study
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
65 | P a g e
Input data
4221 Alternatives
Four alternatives were selected for these study which are one conventional armed concrete
(Reinforced concrete RC) structure prefabricated steel modules (PSM) prefabricated concrete
modules (PCM) and prefabricated timber modules(PTM) that are most common solutions used by
contractors in the construction industry
4222 Requirement tree
These are groups of criteria which define a function to be evaluated A requirement usually
has several criteria Five requirements were selected based by literature review and the expertrsquos
opinions collected by survey among industrial players who were the participants of this questionnaire
Economic R1 time R2 environmental R3 safety R4 and social R5 requirements arranged in a way that
can examine the advantages adequately Time requirement were separated from economic one
because of importance due to high priority that have in the market to be chosen by the constructors
and clients In other words some clients and private builders choose the prefabrication methods such
as modular construction to save more time due to tight schedule that the project have Social and
safety requirements usually not being considered in sustainable decision-making processes but on this
study were included because the sustainability is not the only factor in project management
4223 Criteria
For each requirement a series of criteria are defined Criteria are the specific concepts that
the indicators contain the minimum unit to be quantified (wwwdecaupcedu) Each criterion was
chosen based on the importance among others efficiency on the project and availability of actual
amount and quantities in real cases over literature resources In other words the both advantages
and their functionality that modular construction have in comparison with traditional methods were
the main drivers to choose a criterion for each requirement as it mentioned earlier For economic
requirement cost of the project R1C1 was the only criteria that was considered which in the literatures
is expected to save 20 by choosing modular method in final cost (McKinsey amp Company 2019) while
experts in survey believe that the cost of transportation of prefabricated elements to the site can
compensate the difference with traditional method To examine these two opinions these criteria was
chosen In Time section the projectrsquos schedule R2C1 was only criteria to measure the important
advantage that the modular construction has Both literatures and expert agreed the time saving that
modular approach can bring to the project which is about 50
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES)
R1 - Economic
R1C1 - Project cost
R2 - Time
R2C1 - Project schedule
R3 - Environmental
R3C1 - Energy consumption
R3C2 - Waste generation
R3C3 - Material consumption
R3C4 - Noise Polution
R3C5 - Greenhouse gas emission
R3C6 - Recycle
R3C7 - Embodied energy
R4 - Saftey
R4C1 - Injury risks
R4C2 - Protection from natural cuases
R5 - Social
R5C1 - Job status
R5C2 - Quality
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
66 | P a g e
Seven criteria were chosen to cover the environmental requirements for this decision-making
process based on the available data in literatures However in this section not only advantages of
modular methods were considered but in some areas conventional reinforced concrete showed
better results and this fact can improve the liability and practicality of final decision For instance the
embodied energy of steel modular building is 30 more than the conventional during the construction
but the saving caused by re-useability of element in modular method can almost compensate the gap
between these two methods Energy consumption R3C1 which is the energy consumed during the
constructionfabrication amount of Waste generated R3C2 in all alternatives Material consumption
R3C3 in each method Noise pollution R3C4 Greenhouse gas emission R3C5 Recycle of elements R3C6
and Embodied energy for each method were chosen in this section
Safety issue as it has mentioned before was added to decide further than sustainability
concept boundaries which include two criteria Injury risk for workers R4C1 and Protection of project
from nature causes R4C2
Finally Social benefits which are not as main factors to be considered by construction players
to use the modular methods but are important enough to pay attention and were compared as well
by two criteria Job status R5C1 and Quality R5C2
4224 Indicators
The indicators for this study came directly from scientific articles which most of them were
published few months ago and it can be said that the data which were used for this study is updated
with the latest achievements in modular construction industry
To begin with for economic measurements two indicators for the project cost were selected
total project cost R1C1I1 and costs stability R1C1R2 Total project cost R1C1I1 for conventional RC
alternative means the final cost of construction including all the activities until the delivery of building
In modular alternatives PSM PCM and PTM includes the module fabrication in off-site plants
transportation installation on-site and final finishing of building after the assembly phase All
indicators are based on ldquoAustralian dollarsrdquo units (AUSD) because of the recourse quantities that was
used for this study which will be discussed more later Second indicator which is the costs stability
(R1C1R2) was chosen because of the common off-site production economic advantage that is
stabilizing the costs for the projectrsquos budget because of high quality of product more repetition of
elements and more accurate supervision on activities which leads to less reworks and less extra costs
etc
Total project schedule R2C1I1 is the first indicator for time requirement which include the
amount of time to fabricate transport and final assembly of the modules on-site in modular
alternatives and the final schedule of the conventional project during construction activities until the
delivery of the building which all are based on ldquodaysrdquo it was mentioned earlier that in off-site
production the project schedule can be estimated and controlled more adequately so that second
indicator which is time stability R2C1I2 was introduced to the study
Environmental requirement was studied in various features as it said before in 7 criteria which
shows the complexity of comparisons between alternatives First indicator is the Energy utilized during
construction R3C1I1 based on ldquoMJrdquo units Solid Waste R3C2I1 is the only indicator for Waste
generation criteria that focuses on the amount () of waste which was produced during
constructionfabrication activities in all four activities In material consumption criteria the total
amount of materials that was used for constructionfabrication of elements R3C3I1 is appointed as an
indicator to compare the benefits in each alternative based on ldquoKgrdquo Noise reduction in off-site
construction is another benefit that it has and to discuss this fact among the alternatives Average A-
weighted equivalent sound level of each construction equipment R3C4I1 based on ldquodBrdquo units was
focused on Greenhouse gas emission among alternatives was measured in CO2 that was produced
during constructionfabrication activities R3C5I1 based on ldquoKGrdquo units Two indicators were introduced
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
67 | P a g e
for recycle criteria between four alternatives recyclability or possibility of recycling of elements
R3C6I1 and Re-use of elements (Products) in projects R3C6I2 based on Percentages Embodied energy
was the last criteria which was focused on with two indicators Embodied energy used R3C7I1 in ldquoGjrdquo
units and Embodied energy saved by re-use of elements in percentages among alternatives
For safety measurements two indicators were selected for two criteria which are injury risk
level R4C1I1 for injury risk criteria and Protection level R4C2I1 for protection from nature causes both
in a qualitative unit
Job stability R5C1I1 for comparing the job status in terms of security of jobs among two
methods and new job creation R5C1I2 to analyse the possibility of providing new job positions which
is crucial in these era in construction industry were chosen in qualitative unit
The last criteria in social requirement which is quality of projects was presented with one
indicator of quality satisfaction of client R5C2I1 in qualitative unit to compare the clientrsquos satisfaction
level between alternatives Table 4 1 - Requirement tree with all indicators which considered for decision making process
Requirements Criteria Indicators
(R1) Economic (R1C1) Project Cost (R1C1I1) Total Project Cost
(R1C1I2) Cost Stability
(R2) Time (R2C1) Project schedule (R2C1I1) Total Project Schedule
(R2C1I2) Time Stability
(R3) Environmental
(R3C1) Energy Consumption (R3C1I1) Energy Utilized during construction
(R3C2) Waste Generation (R3C2I1) Solid Waste
(R3C3) Material Consumption (R3C3I1) Material Consumed in project
(R3C4) Noise Pollution (R3C4I1) Average A-weighted Equivalent sound Level of each instrument
(R3C5) Greenhouse Gas Emission (R3C5I1) Co2 in constructionfabrication
(R3C6) Recycle (R3C6I1) Recyclability of Elements
(R3C6I2) Re-use of elements
(R3C7) Embodied Energy (R3C7I1) Embodied Energy Used
(R3C7I2) Embodied Energy Saved
(R4) Safety (R4C1) Injury Risks (R4C1I1) Injury Risk Level
(R4C2) Protection from Nature Causes (R4C2I1) Protection Level
(R5) Social (R5C1) Job Status
(R5C1I1) Job Stability
(R5C1I2) New Job Creation
(R5C2) Quality (R5C2I1) Quality Satisfaction of Client
The input data for indicators are categorized in 4 types direct data calculated data estimated
data and qualitative data The reason for not having only direct data is the lack of enough literature
researches on this subject and in some cases the data were published two months before the date of
this study The variety of alternatives which is the first time that a study is going to analyse 3 modular
alternatives and a traditional method added difficulty to find useful data to do the decision making
reliable Moreover 5 articles were used for finding the correct data which each of them focused on
different alternatives The orientation of this study is the Cleaner Production journal by professor
Hammad that was published in 2019 which was mentioned earlier The reason of this orientation is
that most of the data came from this article and is more updated than the others
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
68 | P a g e
bull Direct Data
The direct data were the information that was related precisely to the alternatives without
any needs to change For instance the cost of the construction in Hammadrsquos article which can be used
without any changes The green parts on the Table 42 shows the direct data which are related to the
Hammadrsquos article Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed to be done on them
bull Calculated Data
In many indicators because of lack of existence in directly related data for alternatives a sort
of calculations were needed to change the data from other articles that related to alternatives that
are not focused in main case (Hammadrsquos article) to actual data based on the area of main article by
using accurate coefficients and ratios For instance in Hammadrsquos article CO2 was not estimated for
Prefabricated Steel Modules (PSM) alternative but Ayersquos CO2 data which is for total area of 3943m2
with 63 apartments each area of 628 m2 (close to 625 m2 area of Hammadrsquos granny flat) was used
by dividing on 63 apartments units so that results 54079 kg of CO2 for steel modular equivalent for
main case The yellow parts show the calculated data for indicators
3407000119896119892 1198881199002 divide 63 119906119899119894119905119904 (6251198982) = 54079119896119892 1198881199002 for steel modules in main case
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other studied
bull Estimated Data
Third type of input data were the necessary data which are not existed on any of literatures
of have to be estimated based on the qualitative information professional survey which have been
done before the decision making process (Chapter 3) and researcherrsquos opinions Fortunately in many
areas the data could be applied on other alternatives because of similarity of activities off-site and
onsite For instance for PCM alternative the noise and Injury risk level are approximately the same
the indicators of PSM case that have mentioned in Hammadrsquos article which are shown in green parts
in Table 42 because of similarity of off and on site activities during construction
The blue parts are the estimated data that were considered for PCM alternative based on
mentioned resources For instance the time indicator can be predicted 24 days few days more the
steel modules which is around 22 days because of the fact that concrete modules are heavier than
steel ones and has more complexity in structure for being produced that adds difficulties on
transportation process which leads to more delays on the schedule Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow)
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
69 | P a g e
bull Qualitative Data
This data was added because of two reasons first the lack of existence of direct data on
literatures and improve the literatures background on this subject and secondly to have more
influence from variety of benefits that modular construction has on the decision making process
Numbers of literatures insisted on advantages that can affect the decision making but did not
included on their data analyses at the end and this research decided to include these data and see
that how much functional can be in the decision making between alternatives in point of project
management view For instance cost stability which is better coordinated in off-site construction and
can be considered as an advantage to the decision making is not included in the literatures during
analysis and in this study is a vital factor for the economic criteria In order to add this indicator a
qualitative range was considered from 0 to 10 and four alternatives based on their functionality in cost
stability in project budget were compared to each other Traditional reinforced concrete building
which because of common reworks etc have less stability in final budget estimation On the other
side PSM and PTM which have the most repetition in manufacturing processes and ease of production
because of material type have the maximum cost stability of 9 out 10 among the others and PCM that
has less ease in production have less cost stability than other modular alternatives with 8 out of 10 Table 4 5 - Qualitative indicators
Final indicators
bull Prefabricated Steel Modules indicators (PSM)
As it mentioned before the direct data which are shown in green at table 46 do not need any
changes as they belong to the main case study while other indicators are still needed to be calculated
estimated and often considered qualitatively Aye case study have the closest data to the main case
study because of similarity of project type and dimensions so that the necessary indicators such as
material consumption waste generation percentage re-use amount and embodied energy indicators
can be calculated from this analytical study (For more information about indicators resources please
see Annex 1-A) Table 4 6 - First hand data over literature
A simple calculation is needed and that is dividing the CO2 emission Material
consumption and Embodied energy used amounts in Aye project on 63 apartment units with the
same area of 625 as main case in Hammads residential flat ldquoWaste amountrdquo ldquore-use of elementsrdquo
and ldquoembodied energy savedrdquo can be applied on the main case because of similarity of material
choices
IndicatorsAltertanives TRC PSM PCM PTM
Cost stability 6 9 8 9
Time stability 6 9 8 9
Recycleability of elements 3 8 7 9
Protection level 2 9 9 9
Job stability 5 8 8 8
New job creation 3 8 8 8
Quality satisfaction 5 9 8 9
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
70 | P a g e
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow)
bull Prefabricated Timber Modules indictors (PTM)
As it can be seen in table 48 there are no enough data over literature in many areas and due
to the necessities for this study a range of calculations and estimation have to be made based on the
similarity of projects among study cases and survey information Table 4 8 - First hand data over literature
Starting with Cost of the project which an ldquoestimationrdquo based on literature review information
and qualitative comparisons (John quale 2012) (Lu Aye2011) that is approximately 45000 AUD
because it proved that the cost of Timer modules is even cheaper than Steel Modules due to simplicity
of material choice and structure design The schedule of PTM building is shorter than the other
alternative because of numbers of reasons such as less weight of elements which can lead to faster
transportation loading and offload in assembly process on-site In addition the manufacturing lines
are simpler than other modular alternatives because of high repetitions and simplicity in design
For ldquocarbon emissionrdquo and ldquomaterial consumptionrdquo Aye project was used by diving on 63
apartment units which have the same area of 625 m2 as main case In terms of ldquowaste generationrdquo a
unique article was used (by Doyoon 2008) which did a LCA study on Timber modular building and the
amount of wastematerial consumed was about 9 The Noise level and Injury risk can be applied
from other modular alternative because of similarity of construction activities and equipment used
for fabrication Energy utilized during construction of Timer modules have the minimum amount in
comparison with other alternatives because of simplicity of material choice and design enhancement
so that was estimated 80MJ which is slightly less than steel modules with 86 MJ
Re-use of elements in timber modular elements was confirmed by survey among the
constructors over than 70 with a life span of 50 years Embodied Energy used was collected from
Aye case study dividing on 63 apartments units as same as other cases which equals to 65671 GJ
(Table 49) Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue)
bull Prefabricated Concrete Modules indicators (PCM)
The least focus on modular alternative was on Concrete Modules which is because of few uses
that this method has among the projects Balasbaneh study focused on a comparison between Steel
modules and Concrete modules in total project cost and LCA Table 4 10 - First hand data over literature
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury risk Energy utilized Re-use Embodied energy Emb saved
Aye 2500000 996 356 41373 691
Quale 13600
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 45000 20 39375 1580952 9 645 163 80 70 65671 691
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Balasbaneh 239380 8264
Units MLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
71 | P a g e
However the currency of this economic analysis is not as AUD (Australian Dollars) as the main
study Therefore to calculate the cost and CO2 footprint corresponding to main study case a ratio
was obtained between concrete modules amounts and steel modules in Balasbaneh study and then
multiplied to the steel modules quantities in Hammadrsquos main case and resulted project cost of
5188603 AUD and 46442 kg of CO2 emissions
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM alternatives
239380 divide 222580 = 1075478 119862119900119904119905 119903119886119905119894119900 (Balasbaneh study case)
482446 times 1075478 = 5188603 119860119880119863 Total project cost of PCM
8264 divide 9623 = 085877 1198621198742 119903119886119905119894119900
54079 times 085877 = 46442 119896119892 CO2 of PCM
The time indicator was estimated based on steel modules but with this difference that
concrete modules weight more than steel ones so that puts pressure on the transportation and
assembly phases and causes delays in the schedule as a result 24 days was predicted to finish the
project
There is no available information on the literature with specific quantitative details however
based on the qualitative structural information prefabricated concrete modules PCM because of their
similarity of material choice to conventional model have a massive material use in comparison with
Steel and Timber alternatives so that an estimated total material consumed of 20000kg assigned for
this indicator (Aye 2011) (Balasbaneh 2020)
Waste generation have a higher ratio in this alternative because of material choices which
generate more waste than other modular alternatives With this fact in mind the waste ratio
considered slightly more than steel kind with 10 (Aye 2011)
Noise level and Injury risk can be applied from other types because of similarity of equipment
and construction activities in all three modular alternatives (Hammad 2019)
Energy utilized during construction in PCM Alternative can be estimated more than steel ones
because of types of materials used in these modules and their high weight with value of 90MJ (Aye
2011)
The structural elements are ldquonotrdquo built in material which have a high recyclability potential so
that decreases the Re-use ratio to 20 approximately in comparison with other modular alternatives
(Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
72 | P a g e
Embodied energy used amount and its potential saving have the minimum value in a
qualitative comparison with other alternatives which respectively values of 800GJ and 60 were
estimated for them (Aye 2011) Table 4 11 - Final indicators for PCM
bull Traditional Reinforced Concrete (TRC) final indicators
The highest focus over the literature is to make a comparison between one of the modular
options and a traditional method which results more availability for direct data for Traditional method
The main case study is not an exception with almost half of the value are available directly such as
Project cost Time Noise level Injury risk and Energy utilized during construction which are shown in
green at table 412 (Hammad 2019) Table 4 12 - TRC first-hand data over literatures
Nevertheless still there are values that must be calculated over literature Green gas emission
indicator and Embodied Energy used were calculated form Ayersquos case study by dividing the values on
63 apartment units which results 3620635kg Co2 emission and 6033 GJ of 625 m2 area as same as
main case study (Aye 2011) (Hammad 2019)
Material consumption have the same methodology as carbon footprint with final value of
626825kg which is massively higher from modular alternatives (Aye 2011) (Hammad 2019)
Waste generation was calculated qualitatively from a literature resource called ldquoModular
Construction for Multifamily Affordable Housingrdquo by WSP which acclaims that the conventional site-
built method produces around 25 times more construction waste (WSP 2018) Thus TRC waste
generation is more than 25 times of modular ones with the value of 15
Two values of Re-use and Embodied energy saved by Re-use of elements were obtained from
Ayersquos case study respectively 22 and 322 (Aye 2011) Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow)
In general the table 414 shows the References and final indicator values that were used for decision
making process (Direct data are shown in Green Calculated data in yellow and estimated data in
blue)
Table 4 14 - Final Quantitative indicators used for decision making process
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 812298 6598 71 217 198
Akbarnejad 120000 67 84672
Aye 2281000 3949 22 38008 322
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
PSM 482446 2131 54079 138254 5 645 163 8593 50 9012 813
PTM 45000 20 39375 1580952 9 645 163 80 70 65671 691
PCM 5188603 24 46442 20000 10 645 163 90 20 800 60
TRC 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrence Ham Aye Balas Hammad Balas Aye Aye Doyoon WSP Aye Hammad Hammad Hammad Aye Aye Aye
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
73 | P a g e
Weights
The Weights (Pesos in MIVES) which are one of the most important factors in decision making
process have be assigned on the data in a way that the priority of each section in terms of efficiency
and importance can decide which value will have among the others AHP method was used to assign
weights on the data In AHP you get the weights through the subjective importance of each element
with respect to the others (Alejandro Josa 2012)
bull Weights of requirments
The importance of requirmenets was assumed based on proffessional survey among
constructors architects sales agents and clients in order to know the demands of market and make
the decision rely on what market expects from a innovative method According to the survey time
reduction is the first priority for choosing the modular methods by constructors and future clients so
than acheived 30 of weight Economic issues came after the time factor because of unconsistency
between responds about cost saving on the budget or offseting the expenses gap by tarnsportation
extra costs on the project Economic requirement has 27 of weight In some regions the priority of
choosing an innovative method are environmental emissions waste generation and recycleability of
products Therefore environmental requirement came after the economic one with 25 of weight
As it mentioned before Social and safety advantages are included in this decision making
process with respectly weights of 13 and 5 because of their less priorities among clients and market
players Table 4 15 - Requirement weights
Requirement Economic Time Environmental Safety Social
Weights 27 30 25 13 5
bull Weights of criteria
In cost and time of project which are single criteria have 100 of weights However for
instance in environmental and AHP method must be used to assign the weights based on the
importance in an environmental consideration The amount of emission that construction activities
can produce and the amount of negative effect on the global environment have been considered for
AHP method in weight assignment process Energy consumption and material consumption have the
priority to consider in LFA analysis because the consumption of primary resources have to be
minimized in a project at the first step and then the emission have to be reduced by changing the
processes etc Finally the ability to re-use and recycle and elements must be improved (Mohammad
Kamali 2017) (John Quale 2012) (Marta Gangolells 2014) Therefore Energy Consumption and
Material consumption have the most weight of 17 Embodied energy with 16 and waste generation
Greenhouse Gas emission and Recycle achieved 15 of weight At last noise Pollution took the least
priority of weights with 5 Table 4 16 - Weights of criteria
bull Weights of Indicators
Both of Economic and Time indicators divided to two sub-categories project cost and time and
their stability ratios with 80 and 20 weights by AHP method
Criteria that are single indicator obviously have 100 of weights However there are two
indicators in recycle criteria Recyclability and Re-use of elements with 40 and 60 weight
respectively Moreover Embodied Energy have is divided to Embodied energy used which is more
CriteriaEnergy
consumption
Waste
generation
Material
Consumption
Noise
pollution
Greenhouse
gas emissionRecycle
Embodied
energy
Weights 17 15 17 5 15 15 16
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
74 | P a g e
important than the other that is saving in embodied energy by re-use because as it mentioned before
in the first place the use have to be minimized and then actions such as re-use of elements have to be
done 70 of weight for Embodied energy use and 30 for Saved Embodied energy are assigned Job
stability and New job creation with weights of 50 each are the Job status indicators (Figure 411)
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software
Value function play an important role on deciding which comparative final value can each
indicator have among the other indicators for each alternative To evaluate the sustainability index
(Is) of each alternative solution value functions assigned and were used (Alarcon et al 2011) The
generic form of a value function is represented by Table 417 which allows to assess the sustainability
(satisfaction) associated with each indicator by transforming the physical units to a dimensionless
value between 00 and 10
Equation 4 1 - Functionality of value function elements
In Eq (41) B is the value of indicator(Iind) for Xmin Xmin is the minimum abscissa value in the
indicator interval assessed X is the abscissa value for the indicator assessed Pi is a shape factor which
defines whether the curve is concave (Pi lt 1) convex (Pi gt 1) linear (Pi = 1) or S-shaped (Pi gt 1) (see
figure 412) Ci approximates the abscissa at the inflexion point Ki tends towards (Iind) at the inflexion
point B the factor that prevents the function from exceeding the range (0 1) is obtained by Eq (42)
Xmax being the abscissa value of the indicator that gives a response value of 1 for increasing value
functions
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
75 | P a g e
Equation 4 2 - B value equation
Figure 4 12 - Possible forms of the value function
Due to the lack of existence of resources for assigning the specific value functions for modular
alternatives some hypotheses that can increase the feasibility and sustainability of project were
considered for the shape P K and C values to select the best form of abacus
In the other side maximum and minimum satisfaction points were selected on the
expectations of a project management view For instance in total project cost indicator case
minimum satisfaction point is 82000 AUD that is slightly more than the traditional reinforced concrete
alternative project cost (812298 AUD) because of the fact that those alternatives should be
considered as a reasonable options which can make saving in final budget Moreover the same rule
can be applied for maximum satisfaction point which is close to the Timber Modular alternative (45000
AUD) to minimize the final budget as much as possible The shape of the abacus was selected as
Convex shape (Convexa in MIVES) because even the least economic saving that an alternative can
achieve have a positive effect on the satisfaction of project and can be given any positive points in a
scale of ldquo0 to 10rdquo But the more the curve closes to the traditional alternative budget the les
satisfaction it can receive (Figure 413)
Figure 4 13 - Value function for total project cost in MIVES
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
76 | P a g e
The following Table 417 includes the value functions which were used for the rest of the
indicators Table 4 17 - Value function for indicators in MIVES
Data analysis
Indicators Values
Indicator data were translated to general normalized values shown in Table 418 amp 419 based
on the given value functions that earlier assigned This step is crucial for next analyses which will be
done to result the criteria and requirement values which lead to sustainability Indexes that can take
the multi-criteria decision As it can be seen these values have the same range of 0 to 1 so that can be
compared in with a common unit Comparisons are obvious in this level because of single value
orientation of each indicator however on following analysis there will be multi-criteria comparisons
which can achieve useful data for future decision-making process Table 4 18 - Indicators normalized values
Table 4 19 ndash Indicator normalized values
Indicators Lower limit Upper limit Max satisfaction Min satisfaction P K C Shape
Total Project Cost 30000 90000 43000 82000 05 05 79900 Concave
Cost stability 0 10 10 5 05 05 55 Concave
Total Project Time 20 75 20 68 05 05 632 Concave
Time stability 0 10 10 5 05 05 55 Concave
Energy Utilized 75 220 80 205 05 05 1925 Concave
Solid Waste 0 100 0 18 08 05 162 Concave
Material Consum 10000 70000 12000 63000 05 05 57900 Concave
Noise Level 58 78 62 72 05 05 71 Concave
CO2 32000 60000 32000 55000 05 05 52700 Concave
Recyclability 0 10 10 0 05 05 1 Concave
Re-use 0 100 60 0 05 05 20 Concave
Embodied energy 600 950 600 915 05 05 8835 Concave
Embodied saved 0 100 90 30 05 05 36 Concave
Injury risk 0 4 155 22 05 05 2135 Concave
Protection level 0 10 10 0 1 001 1 Lineal
Job stability 0 10 9 4 1 001 45 Lineal
New job creation 0 10 10 0 05 05 5 Concave
Quality Satisfaction 0 10 10 0 1 001 5 Lineal
R1C1I1 R1C1I2 R2C1I1 R2C1I2 R3C1I1 R3C2I1 R3C3I1 R3C4I1 R3C5I1
TRC 016 051 024 051 027 029 01 034 092
PSM 094 092 098 092 098 082 099 088 023
PCM 09 081 097 081 097 059 093 088 065
PTM 098 092 1 092 1 064 097 088 085
R3C6I1 R3C6I2 R3C7I1 R3C7I2 R4C1I1 R4C2I1 R5C1I1 R5C1I2 R5C2I1
TRC 073 026 1 024 024 021 02 063 05
PSM 095 094 023 095 094 09 08 092 09
PCM 092 068 064 077 094 09 08 092 08
PTM 098 084 092 085 094 09 08 092 09
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
77 | P a g e
Criteria Values
MIVES analysed each criterion by single or multi-indicator normalized values and resulted
values with a same range of 0 to 1 for following comparisons Table 4 20 - Criteria normalized values
Table 4 21 - Criteria normalized values
To begin with Project Cost (R1C1) criteria values shows that Almost three modular
alternatives performed 3 times more than the traditional method positively caused by hugely less total
project cost (R1C1I1) and great cost stability (R1C1I2) in project final budget The minimum value
belongs to PTM with 097 and slightly more than PSM and PCM is the next alternative with a value of
088 and at last TRC with 023 (Figure 414)
Figure 4 14 - Criteria normalized values
The comparison between modular alternatives in terms of which one can save time on the
schedule is close and it can be said that all three can make the project executed more than 3 times
shorter than traditional approach Timber steel and concrete options with respectively 098 097 and
094 values were compared to the conventional concrete method with 029 value (Figure 415)
R1C1 R2C1 R3C1 R3C2 R3C3 R3C4
TRC 023 029 028 029 009 032
PSM 094 097 099 083 099 088
PCM 088 094 096 059 094 088
PTM 097 098 101 064 096 088
R3C5 R3C6 R3C7 R4C1 R4C2 R5C1 R5C2
TRC 091 045 083 024 021 040 052
PSM 024 096 048 095 090 088 092
PCM 064 077 072 095 090 088 080
PTM 085 091 096 095 090 088 092
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
78 | P a g e
Figure 4 15 - Project Schedule
ldquoEnergy saving potentialrdquo in modular methods are close to the maximum satisfaction point
with timber solution and steel modules while concrete option is on the chase with 096 While
Traditional alternative only have 28 of satisfaction level
ldquoWaste generationrdquo among the alternatives have a different attitude while traditional method
with value of 029 has the most ratio of material waste production modular alternatives are
performing better where steel option have the most reduction with value of 083 and follow to that
timber and concrete options respectively 064 and 054 values PCM alternative as it said before
because of similarity of material choice to TRC have the minimum performance among the other
three (Figure 416)
Figure 4 16 - Waste generation ratios
ldquoMaterial consumptionrdquo criteria are dominated by modular methods which have a high
satisfaction with over than 09 normalized values while TRC performance can be concerning for the
primary resources with 01 normalized value
Previously on this report the fact was mentioned that off-site construction can benefit the
environment with noise reduction during construction activities based on literatures and this study
confirms this advantage by 088 values of all three modular alternatives and 032 value of traditional
RC which is less than half of modular options
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
79 | P a g e
A highlight of this study is about the comparison of CO2 Emissions of alternatives during the
constructionfabrication activities which traditional method have the minimum contamination with a
value of 091 and follow to that Timber option with 085 which is close to the TRC method Later to
that Concrete modules have a value of 064 and the minimum satisfaction belongs to the steel
modules with 024 normalized value This result bring uncertainty to the fact that modular
construction can reduce the Greenhouse gas emission to 30 over the literature review
Figure 4 17 - CO2 Emission normalized values
This study shows that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options with a value of 096 because of the material choice
repetition in element manufacturing and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution have 091 value that can confirm the concept of
recyclability for wooden modules which was mentioned by participants in professional survey as well
Figure 4 18 - Recyclability and re-use potential of alternatives
There is a discussion about the amount of embodied energy used during the lifetime of each
alternative and the potential of future saving by re-use of elements in projects which effect the total
embodied energy consumption in construction
As the Figure 419 explains traditional method has the maximum satisfaction level in terms
of consumption while steel modules have the least satisfaction of life cycle embodied energy used of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
80 | P a g e
023 PTM have a better value of 091 which shows that Timber solution can be reliable among the
others
However this study resulted that the most re-use value belongs to steel option with 095
value that and other two timber and concrete modules respectively with 085 and 077 can
compensate the gap with traditional method that has only 024 Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction total value of 096 Later
traditional reinforced concrete method with 088 still proves its abilities over other two modular
alternatives
Figure 4 19 - Embodied energy consumption and saving potential by reuse
In terms of safety modular alternatives because of their off-site nature can provide a high
satisfaction level with values of 095 in injury risks for workers and 090 protection from nature causes
which confirms the theory of safety advantage of modular construction over traditional methods from
literature studies (Figure 420)
Figure 4 20 - Safety advantage of modular construction over traditional method
Social benefits which were mentioned in literature review section also had been examined in MIVES
system and the job stability and job creation in modular construction can benefits the construction
society in significant way among the regions that have employability ratio problem
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
81 | P a g e
Figure 4 21 - Social criteria
Requirement Values
After analysis on criteria functions general values of each requirement were related to
alternatives achieved which can examinate all four construction methods to know which option is
more suitable in terms of Economic time environmental safety and social issues
The Table 422 below demonstrates the Requirements normalized values for each alternative Table 4 22 - Requirement normalized values for four indicators
bull Economic and Time requirements
As the graph illustrates Modular methods have a significant performance in economic and
time terms with the maximum values of 097 and 094 in Time and 098 and o97 in Economic
requirement for Timber and then Steel modules-based methods respectively Traditional reinforced
concrete option showed a poor functionality in cost and time of project with minimum values of o29
and 023 in order (Figure 422)
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values analysed by MIVES
Requirements Economic Time Environmental Safety Social
TRC 023 029 045 022 046
PSM 094 097 075 093 088
PCM 088 094 078 093 084
PTM 097 098 088 093 088
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
82 | P a g e
bull Environmental requirement
Generally all three modular approaches have beaten the traditional method with almost
double of normalized values in comparison
Despite the poor performance of steel modules in Greenhouse gas emissions and Embodied
Energy used in construction in total numbers proved that can provide the environmental demands
better than traditional option with a value of 075 which is third modular alternative in overall
Prefabricated Timber modules obtained the maximum value of 088 which claims not only
most economic option but environmentally friendly among other relatives and following to that
Concrete modules with value of 078 shows its liability to be chosen in case of need while the
traditional concrete method which includes most of the used materials n PCM but in a on-site plant
only can achieve a satisfaction value of 045 among the others (Figure 423)
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind
bull Safety and social requirements
The dominance of Modular construction in safety and social requirements over conventional
option can be seen in Figure 424 which can raise the possibility of modular methods to be the best
decision over the traditional option to construct this residential project As it was mentioned before
these two criteria must be considered in any decision-making process because of their high
importance in construction industry
Figure 4 24 - Modular dominance in safety and social requirements over conventional option
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
83 | P a g e
Sustainability Values (Final decision)
Finally the sustainability Indexes can be obtained to claim which alternative will be decided
as the most sustainable option for the main studyrsquos project to be build The needs of market such as
short project schedule cheaper budget reduction in environment emissions and ability to
recyclereuse safety measures and social benefits put effects on this decision as previously
mentioned
Table 423 explains that Prefabricated Timber Modules (PTM) is most sustainable alternative
among the other with a perfect normalized value of 094This could be because of its shorter schedule
of construction lowest total budget and excellency in environmental performance among the other
alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative Table 4 23 - SI (Sustainability Indexes related to four alternatives)
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This fact explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives
TRC PSM PCM PTM
SI 032 090 088 094
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
84 | P a g e
5 Conclusions Decision making process
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria etc However to find out how much practical these benefits are in the market several trade-
offs must be done by professional tools such as project management software programs which can
take decisions based on the input data that receive MIVES software was used in this study to
examinate these benefits The resources for this type of studies are limited due to the lack of focus or
newfound nature of this subject and only five of them were selected because of their variety of their
criterion studies reliability and accuracy of data Requirements criteria indicators and weights that
were used in MIVES had been selected based on demands of market and professional opinions
received from the survey and availability of data over references After assigning the value functions
which are related to satisfaction level on each criterion (For instance cost reduction time saving and
minimization of emissions) normalized values were achieved that can be compared between
alternatives with range of 0 to 1
Conclusions and discussion
ECONOMIC ndash TIME discussion
bull Decision-making result
Generally all three modular alternatives have beaten the traditional method with almost
double of normalized values Modular methods had a significant performance in economic and time
terms with the maximum values in Time and Economic requirements for Timber and then Steel
modules Traditional reinforced concrete option showed a poor functionality in cost and time of
project with minimum values
Literature reviews information
These Results confirm the 50 of time saving in projectrsquos schedule (McKinsey amp Company
report 2019) and 20 of cost reduction on the budget which was mentioned also in numbers of
literatures
Professional survey confirmation
In addition the claims from professional participants in survey about the 50 cost reduction
due to the added value of every hour of work in comparison with traditional stick and build on-site
method can be approved even far more those expectations
ENVIRONMENTAL discussion
bull Recyclability and re-use potential
This study showed that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options because of the material choice repetition of
elements in manufacturing line and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution can confirm the concept of recyclability for wooden
modules which was mentioned by participants in professional survey as well
bull Embodied energy used and saving by re-use
There is a discussion over the literature and survey participants about the amount of
embodied energy used during the lifetime of each alternative and the potential of future saving by re-
use of elements in projects which effect the total embodied energy consumption in construction
where one of the companies acclaims that ldquoour homes are not positive in energy consumption
aspectrdquo Traditional method has the maximum satisfaction level in terms of consumption while steel
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
85 | P a g e
modules have the least satisfaction of life cycle embodied energy used PTM have a better value of
091 which shows that Timber solution can be reliable among the others However this study resulted
that the most re-use value belongs to steel option and other two timber and concrete modules
respectively can compensate the gap with traditional method Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction Later traditional reinforced
concrete method still proves its abilities over other two modular alternatives
bull Greenhouse gas emission
Despite the poor performance of steel modules (PSM) in Greenhouse gas emissions that bring
uncertainty to the fact that modular construction can reduce the Greenhouse gas emission to 30
over the literature review and Embodied Energy used in construction proved that can provide the
environmental demands better than traditional option which is third modular alternative in overall
comparison
bull Most environmentally friendly alternative
Prefabricated Timber modules obtained the maximum value which achieves not only most
economic option but environmentally friendly among other relatives Following to that Concrete
modules shows its liability to be chosen in case of need while the traditional concrete method which
includes most of the used materials of PCM but in an on-site plant only can achieve the minimum
value
Comparison with literature review information and survey outputs
This comparison explains the truth about the concept of being environmentally friendly about
modular construction that have been mentioned in various scientific articles (McKinsey amp Company
report 2019) (M Kamali 2016) and the survey results which confirmed the concept in real cases at
the market over years of experience
SAFETY AND SOCIAL dominance by modular methods
The dominance of Modular construction in safety and social requirements over conventional
option was resulted which can raise the possibility of modular methods to be the best decision over
the traditional option to construct this residential project As it was mentioned before these two
criteria must be considered in any decision-making process because of their high importance in
construction industry Social benefits which were mentioned in literature review section also had been
examined in MIVES system and the job stability and job creation in modular construction can benefits
the construction society in significant way among the regions that have employability ratio problem
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES
Prefabricated Timber Modules (PTM) is most sustainable alternative among the other with a
perfect normalized value of 094This could be because of its shorter schedule of construction lowest
total budget and excellency in environmental performance among the other alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This result explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
86 | P a g e
Effective external factors on decision
The decision was made for the best alternative in terms of sustainability for a specific
residential case located in Sydney Australia among three modular options and one traditional
method However there are factors which can affect the final decision obviously Such as the location
of the project which the availability of primary resources can change the or alternatives or number of
indicators The local market and their demands for specific products can be crucial for choosing the
best method which affect the priorities of weights Regulation of every regions as it was mentioned
before can change the project requirements and indicators
The type of the project was a residential building that has its own characteristics but for
instance a school or hospital project would demand a higher functionality and lifetime because of their
distinctive operation kind and evidentially can be considerable in decision-making process to the end
step Special project due to their unique requirements often do not consider all criterions For
instance emergency health stations demanded during the Virus pandemic period have their own
material choose design enhancement and priorities on requirements
Future studies
Due to novelty of this subject there are numbers of studies still remained without coverage
which might be studied in future
Decision making study on two real projects with the input data of professional
modular and traditional constructors
Due to the lack of information over literature there were so many elements that have been
estimated by hypothesis and survey information therefore it is crucial to find these data in order to
do a precise study with real numbers These data can be obtained by requests to industry players to
have access of real project details including budget schedule material consumptions etc By this
action the liability of the study can be improved and accurate results can be achieved Thus a
decision-making process can be done to find out which alternative can be more sustainable
Technological studies about the production line of a modular off-site plant by factory
and on-site visits
There are still uncertainties about the status of use of automation productivity rate etc which
have to be analysed closely Modular construction was suggested as an example of industrialization in
construction industry to improve the productivity rate but corresponding to past survey the majority
of constructors are not benefiting from automation in their production lines and assembly processes
A study is needed on different phases of a project that have to be monitored and analysed scientifically
in order to find challenges errors and possible solutions to make this method even more sustainable
A survey about challenges in modular construction and its possible solutions to find
adequate solutions
Challenges have to focused more on this method because its players are still suffering from
the incompatibility of construction industry and the projectrsquos old conditions with innovative solutions
Series of interviews with experts factory visits etc have to be done to hear the voices of them and
then researchers to find solutions to update the industry and help them for growth
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
87 | P a g e
Recommendations
Cooperation between industrial players and scientific researchers in offsite
construction
Numbers of contrasts where found in the data and results among literatures professional
participants of survey and the decision-making study which shows a poor status of cooperation
between scientific researchers and professional players in the construction industry It is obvious that
the real data from the constructors designers etc in real projects are more reliable than scientific
estimation which in this case were based on BIM models and approximate calculations without any
interruption effects of common challenges in industry There were few participants who did not want
to share their project details in public or even education purposes or in a case one of the most
innovative players in modular industry responded their lack of available time to respond the survey
by direct email These attitudes can increase the gap between two vital elements for improvement
which are science and industry in construction society and to reduce it cooperation must be increased
specially in off-site society
Education about industrialization in construction and its alternatives
The idea of lack of education among engineers and architects who enter the professional
society about off-site construction methods was proved by the collected information from survey
participants which can cause problems in the projectrsquos design coordination and execution processes
These series of errors must be resolved by updating the education resources about innovative
methods such as off-site construction industrialization in construction concept rather than traditional
on-site methods that still occupy most of the educational courses these actions can improve the
common challenges in construction industry such as productivity problem and sustainability rate by
encouraging the researchers even far beyond the boundaries of investigations and make the way
possible to find more innovative solutions such as robotic fabrication 3D concrete printing etc
Establishing international and regional adequate codes
Use of automation is suggested by the researchers and industry players to raise the
productivity and sustainability in construction as the other industries which resulted positively
However constructors and manufacturers are suffering from a lack of exitance of international united
codding for their production line and boundaries and uncertainties by local regulations
To resolve these issues participants addressed an international code similar to what on-site
traditional methods have which the responsibility of creation of these codes are on the shoulders of
researchers and professional experts with a mutual partnership that is only possible with cooperation
of industry with science as it mentioned before
Synchronizing the contract conditions with modular construction conditions
There are numbers of problems in terms of contract conditions such as misunderstanding by
final client who is the end home buyer who ldquobelieves the factory to be the builder and the actual
independent builder to be a sales agent for the factoryrdquo one of the participants mentioned A
recommended solution for this problem is to define the relationships between the participants of
projects their responsibilities For instance requiring the builders customer to sign a disclosure
acknowledgement from that describes the relationship in detail In addition there is a lack of quality
partners on site The problem starts when on-site participants realize the advantages of modular
construction they tend to increase their prices for services which can increase the final prices of
project Another challenge which modular projects can face is the lack of delivery of project on agreed
time with an unacceptable quality of on-site execution The professionals answered that the
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
88 | P a g e
responsibility of ensuring that the work is done properly belongs to the builder which any ldquodelays in
this can result in postponed transport of product and interest through demurrage chargesrdquo
These problems must be solved by defining unique types of contracts that are adapted with
the off-stie construction nature and be obeyed by all the participants globally
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc
The only value that the market considers choosing modular method over traditional
construction is to be cheaper while majority of people the media and even professional engineers do
not understand the capabilities of modular construction Many people continue to confuse this form
of construction with HUD on frame products Another wrong perception that the publicmarket
believes is that the prefabrication methods limits the design options while some players believe that
the reverse is the case Therefore by using one of the main advantages of modular construction which
is shorter schedule the market can be dominated by modular projects and the more cases they
deliver the more recognised this method would be among the public and at the end the superior
nature of modular approach can be proved Another solution is a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Many of these wrong perception and misunderstandings can be
clarified by well-organized advertisements about several advantages that modular construction have
in comparison with conventional methods
Changes in financial strategies and adapting them with off-site construction nature
Financial assists which are crucial for kind of projects that are dependent to these aids are
not harmonized with modular project processes where there are argues that until the first deliveries
of elements to the site location and their assembly these aids will not be reachable This issue creates
pressure on cash flow of project where bank finance is involved Changes in contract conditions and
education for financial supporters are recommended solutions to improve the partnerships in
projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
89 | P a g e
6 References 1) Balasbaneh AT Ramli MZ A comparative life cycle assessment (LCA) of concrete and
steel-prefabricated prefinished volumetric construction structures in Malaysia Environ Sci
Pollute Res (2020) httpsdoiorg101007s11356-020-10141-3
2) Doran D and Giannakis M (2011) An examination of a modular supply chain a
construction sector perspective Supply Chain Management Vol 16 No 4 pp 260-
270 httpsdoiorg10110813598541111139071
3) Lawson RM Ogden RG Bergin R 2012 Application of modular construction in high-rise
buildings Journal of Architectural Engineering httpsdoi101061(ASCE)AE1943-
55680000057
4) Diez R et al (2007) lsquoAUTMOD3 The Integration of Design and Planning Tools for Automatic
Modular Constructionrsquo International Journal of Advanced Robotic Systems httpsdoi
1057725671
5) Lee J Park M Lee H ampamp Hyun H (2019) Classification of Modular Building
Construction Projects Based on Schedule-Driven Approach Journal of Construction
Engineering and Management 145(5) 04019031 httpsdoi101061(asce)co1943-
78620001656
6) Barbosa F Woetzel J Mischke J Ribeirinho M Sridhar M Parsons M Brown S
(2018 July 09) Reinventing construction through a productivity revolution Retrieved
September 28 2020 from httpswwwmckinseycomindustriescapital-projects-and-
infrastructureour-insightsreinventing-construction-through-a-productivity-revolution
7) Quale J Eckelman MJ Williams KW Sloditskie G and Zimmerman JB (2012)
Construction Matters Comparing Environmental Impacts of Building Modular and
Conventional Homes in the United States Journal of Industrial Ecology 16 243-253
httpsdoi101111j1530-9290201100424x
8) Horwitz-Bennett Barbara (2020) Rising to the challenge sl Modular Building Institute
(MBI)
9) Lu N amp Korman TM (2010) Implementation of Building Information Modeling (BIM) in
Modular Construction Benefits and Challenges
10) Institute Modular Building 2019 Permanent Modular Construction Canada Modular
Building Institute
11) Josa A (2012) Introduccioacuten a MIVES y el anaacutelisis multicriterio Jornada sobre la Importancia
de un meacutetodo para la toma de decisiones modelo MIVES para una ingenieriacutea sostenible
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
90 | P a g e
12) Aye L Ngo T Crawford R H Gammampila R amp Mendis P (2012) Life cycle greenhouse
gas emissions and energy analysis of prefabricated reusable building modules Energy and
buildings 47 159-168
13) Kamali M amp Hewage K (2016) Life cycle performance of modular buildings A critical
review Renewable and sustainable energy reviews 62 1171-1183
14) Lawson M Ogden R Goodier C (2014) Design in Modular Construction London CRC
Press httpsdoiorg101201b16607
15) Generalova E M Generalov V P amp Kuznetsova A A (2016) Modular buildings in modern
construction Procedia engineering 153 167-172
16) Thompson J (2019) Modular Construction A Solution to Affordable Housing Challenges
Cornell Real Estate Review 17(1) 21
17) Modular construction for multifamily affordable housing (2018) WSP
httpscdnymawscomwwwnibsorgresourceresmgrosccepa-modular-construction-
forpdf
18) Hammad A W A amp Akbarnezhad A (2017) Modular vs conventional construction a
multi-criteria framework approach In ISARC Proceedings of the International Symposium on
Automation and Robotics in Construction (Vol 34) IAARC Publications
19) Ferdous W Bai Y Ngo T D Manalo A amp Mendis P (2019) New advancements
challenges and opportunities of multi-storey modular buildingsndashA state-of-the-art review
Engineering Structures 183 883-893
20) Bertram N Fuchs S Mischke J Palter R Strube G amp Woetzel J (2019) Modular
construction From projects to products McKinsey amp Company Capital Projects amp
Infrastructure 1-34
21) Hsu P Y Aurisicchio M amp Angeloudis P (2020) Optimal logistics planning for modular
construction using multi-stage stochastic programming Transportation Research Procedia
46 245-252
22) Rausch C Nahangi M Perreault M Haas C T amp West J (2017) Optimum assembly
planning for modular construction components Journal of computing in civil engineering
31(1) 04016039
23) Connor G Jones C E amp Finney S J (2014) Easing future low voltage congestion with an
AC chopper voltage regulator httpsdoi 101061(ASCE)CO1943-78620001001
24) Ahn Y H amp Kim K T (2014) Sustainability in modular design and construction a case
study of lsquoThe Stackrsquo International Journal of Sustainable Building Technology and Urban
Development 5(4) 250-259
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
91 | P a g e
25) Gunawardena D Mendis P Ngo D Aye L amp Alfano J (2014) Sustainable prefabricated
modular buildings httpsdoi 10131402148473920
26) Olearczyk J Al-Hussein M Bouferguene A amp Telyas A (2009) Virtual construction
automation for modular assembly operations In Construction Research Congress 2009
Building a Sustainable Future (pp 406-415)
27) Woźniak-Szpakiewicz E (2016) EU migrant crisis and increasing demand for modular
construction modular social housing complex for refugees in Munich In Back to the Sense
of the City International Monograph Book (pp 921-931) Centre de Poliacutetica de Sogravel i
Valoracions
28) Wunderlich-Malec 2019 The Modular Solution to Reduce Total Construction Costs
httpswwwslidesharenetJoelGil2wuderlich-malec-engineering-modular-construction
29) HAMMAD AWA AKBARNEZHAD A WU P WANG X and HADDAD A 2019 Building
information modelling-based framework to contrast conventional and modular construction
methods through selected sustainability factors Journal of Cleaner Production [en liacutenea] vol
228 pp 1264ndash1281 ISSN 0959-6526 DOI httpsdoiorg101016jjclepro201904150
Disponible en httpwwwsciencedirectcomsciencearticlepiiS0959652619312296
30) HONG J SHEN GQ LI Z ZHANG B and ZHANG W 2018 Barriers to promoting
prefabricated construction in China A costndashbenefit analysis Journal of Cleaner Production
[en liacutenea] vol 172 pp 649ndash660 ISSN 0959-6526 DOI
httpsdoiorg101016jjclepro201710171 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS0959652617324782
31) LOPEZ D and FROESE TM 2016 Analysis of Costs and Benefits of Panelized and Modular
Prefabricated Homes Procedia Engineering [en liacutenea] vol 145 pp 1291ndash1297 ISSN 1877-
7058 DOI httpsdoiorg101016jproeng201604166 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS1877705816301734
32) NEELAMKAVIL J 2009 Automation in the Prefab and Modular Construction Industry [en
liacutenea] Sl sn DOI 1022260ISARC20090018 Disponible en
httpwwwiaarcorgpublicationsproceedings_of_the_26th_isarcautomation_in_the_pref
ab_and_modular_construction_industryhtml
33) SANTIAGO M ALBERTO J MARIA NJ and PATRICIA G 2008 Building industrialization
robotized assembly of modular products En M ONORI (ed) Assembly Automation [en
liacutenea] vol 28 no 2 pp 134ndash142 ISSN 0144-5154 DOI 10110801445150810863716
Disponible en httpsdoiorg10110801445150810863716
34) McGeorge D amp Zou P X (2012) Construction management new directions John Wiley amp
Sons
35) Fieldwire (2018) Why the Construction Industry Is Stuck in the Past
httpswwwfieldwirecomblogis-construction-stuck-in-the-1960s
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
92 | P a g e
36) Construction industry - Office for National Statistics (2019) ONS
httpswwwonsgovukbusinessindustryandtradeconstructionindustry
37) Timmer M P O Mahony M amp Van Ark B (2007) EU KLEMS growth and productivity
accounts an overview International Productivity Monitor 14 71
38) Smith A (2011 September 22) Agile and Lean for Construction SlideshareNet
httpswwwslidesharenetadrianlsmithagile-and-lean-for-construction-9384237
39) The massive opportunity of digitization in Engineering amp Construction (2019)
JourneyappsCom httpsjourneyappscomblogmassive-opportunity-digitization-
engineering
40) Tapscott D amp Tapscott A (2018) Blockchain Revolution How the Technology Behind
Bitcoin and Other Cryptocurrencies Is Changing the World (Reprint ed) Portfolio
41) Can Blockchain Fix the Construction Industryrsquos Productivity Problem (2018) Enstoa
httpsenstoacomblogcan-blockchain-fix-construction-industrys-productivity-problem
42) Itanola M (2019 June 5) Hey Quantity Surveyor is BIM going to take your job Blaze
Threads httpswwwblazethreadcomhey-quantity-surveyor
43) BIM Community (2017) Remodeling Construction Industry with Digitization BIM and
Reality Capture httpswwwbimcommunitycomnewsload563remodeling-
construction-industry-with-digitization-bim-and-reality-capture
44) Kolarevic B (2003) Digital production Architecture in the digital age design and
manufacturing 38-63
45) Labonnote N Roslashnnquist A Manum B amp Ruumlther P (2016) Additive construction State-
of-the-art challenges and opportunities Automation in construction 72 347-366
46) Kapoutsis A C Chatzichristofis S A Doitsidis L de Sousa J B Pinto J Braga J amp
Kosmatopoulos E B (2016) Real-time adaptive multi-robot exploration with application to
underwater map construction Autonomous robots 40(6) 987-1015
47) Khoshnevis B (2004) Automated construction by contour craftingmdashrelated robotics and
information technologies Automation in construction 13(1) 5-19
48) R Alice (2019) CRYSTAL PALACE SHOWER TALK httpsbloginoxstylecomencrystal-
palace
49) Eba (2014) HISTORY ldquoballoon framingrdquo the first prefabricated building system (US)
Architecture for the 99 httpslikemyplacewordpresscom20140214history-balloon-
framing-the-first-prefabricated-building-system-us
50) Peter Goumlssel Arnt Cobbers Oliver Jahn (2012) A Brief History of Prefab ArchitectureWeek
httpwwwarchitectureweekcom20121003design_1-1html
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
93 | P a g e
51) Merin G (2018) AD Classics Habitat 67 Safdie Architects ArchDaily
httpswwwarchdailycom404803ad-classics-habitat-67-moshe-safdie
52) Sveiven M (2018) AD Classics Nakagin Capsule Tower Kisho Kurokawa ArchDaily
httpswwwarchdailycom110745ad-classics-nakagin-capsule-tower-kisho-kurokawa
53) Modular Building Experience | Deluxe Modular (2020)
httpswwwdeluxemodularcomexperience
54) Applications | Modular Construction | Bathroom Pods (2020) Howick Ltd
httpswwwhowickltdcomapplicationsmodular-constructionbathroom-pods
55) Project types (2018) Panel built httpswwwpanelbuiltcomblogmodular-building-types
56) Mobile Mini Merger - WillScot (nd) Willscot httpswwwwillscotcomAboutMobile-
Mini-Merger
57) Teague L (2017) Urbantainer breaks down the negative stereotypes of modular building
Frameweb httpsframewebcomarticleurbantainer-breaks-down-the-negative-
stereotypes-of-modular-building
58) Modular construction (nd) SteelconstructionInfo
httpswwwsteelconstructioninfoModular_construction
59) Modular V (2020) What Is Modular Building Construction Your Ultimate Guide Vanguard
httpsvanguardmodularcomabout-modular
60) Permanent Modular Construction Annual Report 2019 | Modular Building Institute (2019)
MBI httpswwwmodularorgHtmlPageaspxname=pmc-2019-home
61) Modular Construction Foundation (2020) Triumph Modular
httpswwwtriumphmodularcomabout-triumphour-servicesconstruction-
managementfoundations
62) Weights and Dimensions (2020) ITF httpswwwitf-oecdorgweights-and-dimensions
63) Sajip J (2019) Modular Construction A Sustainable Building Method NY-Engineers
httpswwwny-engineerscomblogmodular-construction-a-sustainable-building-
methodWeights and Dimensions (2020 August 28) ITF httpswwwitf-oecdorgweights-
and-dimensions
64) Muresan F (2019) What is Modular Construction NY-Engineers httpswwwny-
engineerscomblogwhat-is-modular-construction
65) ADVANTAGES of using SurePods prefabricated modular bathroom pods (nd) SurePods
httpswwwsurepodscomspeed
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
94 | P a g e
66) EasyPads - The easy-to-use foundation system for modular buildings (2019 March 23)
EasyPads - Foundation System httpseasypadscouk
67) Honrubia M amp Mendonccedila A (2019 June 18) The Benefits of Reusable and Modular
Constructions Ennomotive httpswwwennomotivecomreusable-modular-
constructions
68) Cosentino (2020) Discover Cosentino and all the characteristics of its materials
httpswwwcosentinocom
69) Al-Hussein M Manrique J D amp Mah D (2009) North Ridge CO2 analysis report
comparison between modular and on-site construction University of Alberta Canada
70) Vickers H (2017) Modular construction 4 health and safety benefits Building 4 Education
httpsb4edcomArticlefour-health-and-safety-benefits-of-modular-construction
71) PRISM (2020) HGA and The Boldt Company build STAAT ModTM critical care units to
address the COVID-19 hospital bed shortage PRISM Modular construction 4 health and
safety benefits Building 4 Education httpsb4edcomArticlefour-health-and-safety-
benefits-of-modular-construction
72) Harrouk C (2020 September 28) Mayor of London Launches Housing Design App to
Transform Construction ArchDaily httpswwwarchdailycomauthorchristele-harrouk
73) Schoenborn J (2012) A case study approach to identifying the constraints and barriers to
design innovation for modular construction (Doctoral dissertation Virginia Tech)
74) Casas prefabricadas inHAUS (nd) servicio post-venta casa modular archivos InHAUS
httpscasasinhauscomfranceestagservicio-post-venta-casa-modular
75) Catalunya U U P (nd) MIVES mdash Departamento de Ingenieriacutea Civil y Ambiental mdash UPC
Universitat Politegravecnica de Catalunya UPC httpsdecaupceduesproyectosmives
76) Kim D (2008) Preliminary Life Cycle Analysis of Modular and Conventional Housing in
Benton Harbor MI (Doctoral dissertation)
77) Gangolells M Casals M Forcada N amp Macarulla M (2014) Analysis of the
implementation of effective waste management practices in construction projects and sites
Resources conservation and recycling 93 99-111
78) Alarcon B Aguado A Manga R amp Josa A (2010) A Value Function for Assessing
Sustainability Application to Industrial Buildings Sustainability 3(1) 35ndash50
httpsdoi103390su3010035
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
95 | P a g e
Anexo 1
a) Indicators resources
o Prefabricated Steel Modular (PSM)
Table A1 1 ndash Cost of project PSM (Hammad 2019)
Table A1 2 -Time of project PSM (Hammad 2019)
Table A1 3 - Energy utilized during construction (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
96 | P a g e
Figure A1 1 - Injury risks for workers (Hammad 2019)
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
97 | P a g e
Figure A1 3 - Co2 amount (Aye 2011)
o Prefabricated Concrete Modular (PCM)
Figure A1 4 - Total project cost (Balasbaneh 2020)
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
98 | P a g e
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter)
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020)
o Prefabricated Timber Modular (PTM)
Figure A1 8 - Co2 emission (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
99 | P a g e
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
o Traditional Reinforced Concrete (TRC)
Table A1 6 6 - Projects cost (Hammad 2019)
Table A1 7 - Projects schedule (Hammad 2019
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
100 | P a g e
Table A1 8 - Energy utilised during construction process (Hammad 2019)
Figure A1 9 - Injury risks for workers (Hammad 2019)
Figure A1 10 - Noise level (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
101 | P a g e
Figure A1 11 - Greenhouse gas emission (Aye 2011)
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
102 | P a g e
Anexo 2 1 Survey Q amp A
Q How many years of experience do your company have in modular construction
industry Table A2 1 - Professional experience of the company
Company Responses
A 10-15
B 10-15
C 20-30
D 20-30
E 30-50
Q How many years of experience do you have in the modulartraditional construction
and what is your job position Table A2 2 - Personal experience of participant
Company Responses
A 15 years
B 13 years sales manager
C 30 years of which the last 25 have been as design architect
D Quantity Surveyor
E 3 years Foreign Trade Manager
Q What types of modules your company products in terms of material Table A2 3 - Type of modules
Company Responses
A Wood Steel
B Wood
C Wood
D Wood
E Counter and Fibber cabins Steel
Q Which types of projects you did so far Table A2 4 - Type f projects
Company Responses
A Residential houses
B Schools Residential houses Commercial buildings
C Residential houses
D Schools Residential houses Hospital Commercial buildings
E Schools Residential houses hospital Commercial buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
103 | P a g e
Q Num of employees num of factories and num of modules build Table A2 5 - Characteristics of production range
Company Responses
A 80 employees 1 factory 200 modsyear
B 130 1 490
C 15
D 50 Employees 2 factories 80 build
E 250 employees 2 factories 100000 m2 prefabricated 5000 containers 1000 cabinets TURKEY
Q What was your motivation to choosework in modular construction Table A2 6 - Motivation for doing modular construction
Company Responses
A High demands in market and lack of provide Innovation
B Economic profit
C Environmental benefits High demands in market and lack of provide Innovation Shorter construction schedule due to need Economic profit
D Shorter construction schedule due to need Innovation
E Economic profit
Q Do you have sup-contracts for your panels or they had built in your factories what
is the reason for this decision Table A2 7 - Panel production conditions
Company Responses A build our own
B PE design and approvals fire suppression design and installation ceramic tile Energy Star design and inspection are all subcontracted
C All built in house in our own workshop We have developed our own unique systems which are not available elsewhere
D build in factory - programme cost
E
EPS isolated panels are produced in our factories The other are being purchased from domestic market Standard is EPS isolation and its fixed costs are lower because of quantity The others are not standard investment in production is not feasible
Q What is the level of automation technologies you use in off-site and on-site
production and assembly Table A2 8 - Level of automation
Company Responses
A Extraordinarily little today investing in this heavily this year want to get to 80
B 20
C Off-site 60 on site 20
D 20
E 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
104 | P a g e
Q Does A modular project have a smaller number of labours Less wages of salary off-
site and on-site due to specialization of workforce Does the more value added in
each hour of work can compensate Table A2 9 - Laboral status
Company Responses
A Fewer labour hours and at less cost per hour 1 hour in the factory is equal to 4 on site
B Prefabricated systems-built modular construction generally has a smaller on-site labour force for a shorter period
C Labour similar but more efficient working off site
D Yes (less no of workers and wages) - no need for special work force
E -
Q Do you have any case of recycle and reuse the structuralnon-structural elements in
your projects Table A2 10 - Recycle and Re-use
Company Responses
A Yes
B Yes
C No
D No
E Yes
Q Do you upgrade the modules with other environmentally friendly technologies such
as solar panels in your projects Please give us some examples Table A2 11 - Innovative technology integration
Company Responses
A Our homes are all self-powered only company in the world to be doing this
B
This factory allows for site installation of solar panels and other energy savings processes on site by the independent builderbuyer of our modular building materials Modular makes the most sense to be used by architects and builders with environmentally friendly tech
C
Modules (flat packed floor wall and roof components) are constructed of ply and highly insulated with non-petroleum-based insulation (recycled glass as a fibre) Solar panels fitted as an add on to completed building
D None yet not been asked
E Solar technology is YES
Q Automation in off-site production generates less or more waste of material There
are some argues about less waste generation in manual activities because of better
sense of material resistance by normal labour (wooden material for instance) Table A2 12 - Automation status on waste generation
Company Responses
A we are not automated yet but believe automation will be much more efficient use of materials
B In our experience as a custom modular manufacturer automation has a significant cost that may not be recoverable for many months if not years- millions of dollars in cost of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
105 | P a g e
components set up and training versus hourly wage and benefits of trained factory workers
C Waste is much reduced and a proportion of the waste is remanufactured to smaller items or sold on to handymen
D Would be less waste but we do not use much automation
E -
Q How much reduction does off-site modular construction has in generating ldquowasterdquo in
comparison with traditional construction methods Table A2 13 - Reduction of waste
Company Responses
A 70 less waste
B I am unable to provide an answer to this question
C
As we are timber people emissions are low regardless of construction methods Steel and concrete use are kept to a minimum and these are the high emission materials
D We are still working on our carbon footprint
E 15 less carbon emission
Q How much reduction has in ldquoenergy consumptionrdquo off-site in comparison with
conventional on-site construction What about during the operation phase Table A2 14 - Energy consumption status
Company Responses
A Our homes are not positive from an energy perspective
B
Energy consumption of a factory is known and relatively constant on a weekly monthly and annual basis The modular components for a two-box ranch style house require 3 workdays on our factory floor and 4 more days in final finish prior to shipment A competent and experienced modular builder can many times finish the entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-built house could require as much as 4 months for the same completion
C Not assessed but doubt there is much difference
D We are still working on our carbon footprint
E 30 energy saving
Q Did you deliver any projects for providing emergency services in Covid-19 period You
can mention the projects in the other section Table A2 15 - Delivery of projects in COVID-19 pandemic period
Company Responses
A No
B No
C No
D No
E Yes
Q Did you construct any projects for world aid organizations and charities You can
mention them in the other section
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
106 | P a g e
Table A2 16 - Aid organization project delivery
Company Responses
A No
B No
C No
D No
E Yes
Q Do you offer post-sale services to your clients Table A2 17 - Post-sale services to client
Company Responses
A Yes
B No
C Yes
D Yes
E Yes
Q How much was your initial costs estimate (Factory set up etc) How long was the
investmentrsquos payback period Table A2 18 - Initial costs
Company Responses
A 20 million Canadian dollar 5-year payback
B What costs Factory set up or cost of modular product sold to builders What about labour engineering transportations etchellip
C The business has been building up over decades so it is not possible to isolate specific costs
D -
E 15 million USD 5 years
Q Which factors can change the initial costs Table A2 19 - Effective factors on initial costs
Company Responses
A Level of automation Product types and production range Less sub-contracts Site location
B Design of modular building- ie roof system high wind heavy snow loads etchellip Product types and production range Site location
C Financing Level of automation Product types and production range Less sub-contracts
D Level of automation Product types and production range Site location
E Level of automation Product types and production range
Q Can component re-use building portability and the life cycle value of materials be
used as a strategy to ldquocompensaterdquo for higher initial construction costs Table A2 20 - Re-use effect on budget
Company Responses
A -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
107 | P a g e
B
We use many lumber cut-offs PVC drainpipes and conduit and dry wall pieces over many modular orders Unusable drywall shingle and PVC pieces are collected and sent out for recycling Wood is collected and recycled into mulch product or used for heating by others
C Not easily Our methods (flat pack) due not lend themselves to building portability
D -
E 50 years life span of the products
Q Which factors did you consider for choosing modular construction over traditional
method Table A2 21 - positive factors about modular construction to be chosen
Company Responses
A traditional construction is broken
B
Speed ease and cost of overall construction Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
C Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
D Transportation costs and boundaries Local salary wages
E Transportation costs and boundaries Local salary wages Environmentally friendly
Q Do use BIM in your projects what are the challenges in using BIM Table A2 22 - Use of BIM in projects
Company Responses
A 100 BIM from conceptual to finished models
B No
C No
D No
E No
Q What effects the production line can have on the design Are there any boundaries
on the architectural design Table A2 23 - Influence of production line on design
Company What effects the production line can have on the design Are there any boundaries on the architectural design
A No you just need to design with our subassemblies in mind
B This factory maximum module dimension capability is 15rsquo9
C Workshop prefabrication gives the architect far more design freedom
D Width of building for transport to make economically viable
E No
Q Is there any lack of knowledge from architects or design engineers in modular industry
about production line processes transportation limitations etc
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
108 | P a g e
Table A2 24 - Lack of knowledge among experts
Company Responses
A Yes
B No
C NA
D Yes
E Yes
Q How state transport regulation and approval can harm the projects in cost and time
Have you experience delays in your schedules because of those Table A2 25 - Transportation regulation effect on projects
Q Does the concept of transportable materials add extra costs on the project Do the
reduction of material waste and multiple discounts can ldquocompensate the lossrdquo Table A2 26 ndash Transportable material choice and its effects
Company
Does the concept of transportable materials add extra costs on the project Do the reduction of material waste and multiple discounts can ldquocompensate the lossrdquo
A Transportation costs are offset by speed of production and reduced financing costs for the project
B Not significantly
C See 26 The reverse applies
D No
E No
Q What are the difficulties in using automation in off-site production processes Table A2 27 - Challenges of using automation
Company Responses
A Codding Integration with advanced software
B Cost
C -
D Integration with advanced software
E Codding Cost Lower salaries of manual processes by labour
Company
How state transport regulation and approval can harm the projects in cost and time Have you experience delays in your schedules because of those
A Yes Some areas are slow to respond
B
Yes Some states in the US are more difficult to ship oversized and ldquosuper loadsrdquo through This adds both time and expense to the projects
C No Our company prefabricates and flat packs so all components are within or close to legal load limits
D No
E Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
109 | P a g e
Q Which problems exist in modular construction in terms of contracts What are the
solutions Table A2 28 - Contract condition in modular industry
Q What are the challenges in defining responsibilities among participants of a project
due to the changing most of the activities to precast solutions Table A2 29 - Participation status in modular projects
Company
What are the common errors than can harm the synchronization of productivity between off-site production transportation and on-site installation progress For instance less demands on-site caused
A Lack of quality partners on site that see the benefits of modular and therefore increase their pricing
B
The builder owns the responsibility to ensure that site work is done on time and correctly Delays in this can result in postponed transport of product and interest through demurrage charges
C Provided control is tight none
D -
E -
Q Considering all components are prefabricated offsite what is the role of an outside
general contractor Table A2 30 - Role of outside general constructor
Company Responses
A will always need some component of site work to complete the project
B
An outside general contractor is the independent builder The modular factory is a material vendor to the general contractor The general contractor is responsible for all site work and permits as well as storage- installation- and finish of the modular product forming the house or structure they are building
C We do not use outside general contractors All stages from earliest concept design to completed building are in house
Q How often advantageous changes must be done in the production line and what are
the challenges
Company Which problems exist in modular construction in terms of contracts What are the solutions
A Every state has a different building code need a universal code
B
In some cases the end home buyer believes the factory to be the builder and the actual independent builder to be a sales agent for the factory Our company addresses this through accuracy in the relationship described on our website and social media as well as requiring the builders customer to sign a disclosure acknowledgement from that describes the relationship in detail
C Banks do not recognise work done until it is erected on site This creates cash flow pressure where bank finance is involved
D -
E Delivery on time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
110 | P a g e
Table A2 31 - Changes in production line and its effects
Company Responses
A Slows down production
B This company incorporates changes to product materials or procedures between orders A change in process will not occur that affects only some of the components of an order
C Not sure I can answer that ion the space All means of production have advantages and challenges We have chosen methods and stick to them
Q Do you have sub-contracted players involved in your project for site preparation and
foundation phase etc why Table A2 32 - Site preparation status
Company Do you have sub-contracted players involved in your project for site preparation and foundation phase etc why
A Yes Because we are selling in many geographic areas we need local representation
B No This is the responsibility of our customer- the general contractorindependent builder
C Yes Under direct supervision Their equipment is expensive and not portable It makes sense to use local contractors for footings
D -
E Yes
Q If the onsite foundation is constructed by an outside general contractor are there
additional challenges at the interface in terms of a technology gap the equipment or
tools used the construction experience of workers or in scheduling and phasing of
construction Table A2 33 - Challenges with sub-contractors for site preparation phase
Q What are the wrong perceptions about modular products among market and public Table A2 34 - Wrong perceptions for modular products
Company What are the wrong perceptions about modular products among market and public
A that their only quality is being cheaper
B
In the USA many people the media and even professional engineers do not understand the capabilities of modular construction Many people continue to confuse this form of construction with HUD on frame products
C With our methods (flat pack) that prefabrication reduces the design options The reverse is the case
Company
If the onsite foundation is constructed by an outside general contractor are there additional challenges at the interface in terms of a technology gap the equipment or tools used the constructionhellip
A we need to educate most local subs on our process and reason for doing things a certain way
B Not that directly affects the factory
C No
D -
E -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
111 | P a g e
Q What strategies are taken among manufacturers to either improve the public
perception of modular construction or to promote its advantages to architects and
potential clients Table A2 35 - Solutions for wrong perceptions
Company
What strategies are taken among manufacturers to either improve the public perception of modular construction or to promote its advantages to architects and potential clients
A Going fast Proving the superior nature of our homes by getting more of them into the world
B
There is some cooperation between builders manufacturers architects and engineers to educate the public The national entity is the Modular Home Builders Association See httpswwwmodularhousingcom
C Nothing specific We advertise our advantages and it is enough
Q Any other challenges and recommended solutions for them that you want to add
please Table A2 36 - Recommendations
Company Responses
A -
B -
C The capital cost of equipment Specialised digital equipment is expensive making it difficult for small and medium companies to enter the market
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Architectural challenges 43
Transportation challenges 44
Wrong perceptions among public and real estate market 45
Integration of advanced software 46
Redefining the contracts 46
Supply chain-transportation-onsite assembly management errors 47
3 Common challenges in modular construction industry by a survey 48
Methodology 48
Objective 48
Role of the researcher 48
Ethical considerations 48
Survey setting 48
Development of questionnaire 49
Participant profile 50
Experience amp professions 50
Data collection 51
General information 51
Economic issues 52
Environmental status 52
Social Benefits 53
Initial costs 54
Design limitations 55
Transportation Limitations 55
Project management challenges 56
Social challenges 57
Data analysis amp conclusions 57
Advantages 57
Challenges discussion 58
4 Decision making based on potential advantages among three modular alternatives and
conventional construction method in a project by MIVES software 60
Methodology 60
Objective 60
What is MIVES 60
Data collection process 60
Case Study references 60
Input data 65
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Final indicators 69
Weights 73
Data analysis 76
Indicators Values 76
Criteria Values 77
Requirement Values 81
Sustainability Values (Final decision) 83
5 Conclusions 84
Decision making process 84
Conclusions and discussion 84
ECONOMIC ndash TIME discussion 84
ENVIRONMENTAL discussion 84
SAFETY AND SOCIAL dominance by modular methods 85
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES 85
Effective external factors on decision 86
Future studies 86
Decision making study on two real projects with the input data of professional
modular and traditional constructors 86
Technological studies about the production line of a modular off-site plant by factory
and on-site visits 86
A survey about challenges in modular construction and its possible solutions to find
adequate solutions 86
Recommendations 87
Cooperation between industrial players and scientific researchers in offsite
construction 87
Education about industrialization in construction and its alternatives 87
Establishing international and regional adequate codes 87
Synchronizing the contract conditions with modular construction conditions 87
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc 88
Changes in financial strategies and adapting them with off-site construction nature 88
6 References 89
Anexo 1 95
Anexo 2 102
1 Survey Q amp A 102
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study 4
Figure 2 2 - UK productivity status (Office for National Statistics -ONS) 5
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS) 5
Figure 2 4 - Value added comparison among industries (ennovacom) 6
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom) 6
Figure 2 6 - Fragmentations between construction industry players and their various productivity
rates (McKinsey 2019) 7
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom) 8
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom) 9
Figure 2 9 - Digital construction organization (wwwbimcommunitycom) 9
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom) 10
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom) 11
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom) 11
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8
meters (modulartch) 12
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau) 13
Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
14
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom) 15
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom) 16
Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom) 17
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom) 17
Figure 2 20 - Production steps of floor cassette to walls and their attachment together
(wwwhowickltdcom) 18
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom) 19
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom) 19
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom) 20
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom) 20
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom) 21
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-
Malec (wmengcom) 21
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo) 22
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
23
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported
module (wwwsteelconstructioninfo) 24
Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the
lower levels (wwwsteelconstructioninfo) 25
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other
metals (vanguardmodularcom) 26
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma
Beton) 26
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction
report MBI 2019) 28
Figure 2 34 - Overlaps of phases in modular construction project 29
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom) 30
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method
(McKinsey amp Company 2019) 31
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom) 33
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom) 33
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes) 34
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom) 34
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk) 35
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images) 36
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site
(wwwcadoltocom) 37
Figure 2 44 - various layers of a module building unit including insulations
(wwwsteelconstructioninfo) 38
Figure 2 45 - Compartment floor at junction with external wall and compartment wall
(wwwsteelconstructioninfo) 39
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use
inside convention centres arenas and temporary structures Image courtesy of HGA and The Boldt
Company (prismpubcom) 40
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The
Boldt Company 40
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction
(archdailycom) 41
Figure 2 49 -Balance between Initial costs and Economical benefits 42
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects
(casasinhauscom) 46
Figure 2 51 - synchronization between supply chain transportation and on-site assembly 47
Figure 3 1 - Online office forms for survey use 49
Figure 3 2 - Questionnaire development 50
Figure 3 3 - Participants motivations to start a modular company 51
Figure 3 4 - Re-use potential 53
Figure 3 5 - Contribution in Covid19 epidemic 53
Figure 3 6 - Post sale services por future clients 54
Figure 3 7 - effective factors in initial investments for start-up companies 54
Figure 3 8 - Lack of knowledge among designers and engineers 55
Figure 3 9 - challenges of using automation in off-site plants 56
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study
(WAHammad 2019) 61
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and
conventional methods (Akbarnezhad 2019) 61
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020) 62
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017) 62
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad
2017) 63
Figure 4 6 - Architectural section of multi-residential building (Aye 2011) 63
Figure 4 7 - Structural elements used in modules (Aye 2011) 64
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012) 64
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES) 65
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM
alternatives 71
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software 74
Figure 4 12 - Possible forms of the value function 75
Figure 4 13 - Value function for total project cost in MIVES 75
Figure 4 14 - Criteria normalized values 77
Figure 4 15 - Project Schedule 78
Figure 4 16 - Waste generation ratios 78
Figure 4 17 - CO2 Emission normalized values 79
Figure 4 18 - Recyclability and re-use potential of alternatives 79
Figure 4 19 - Embodied energy consumption and saving potential by reuse 80
Figure 4 20 - Safety advantage of modular construction over traditional method 80
Figure 4 21 - Social criteria 81
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values
analysed by MIVES 81
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind 82
Figure 4 24 - Modular dominance in safety and social requirements over conventional option 82
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives 83
Figure A1 1 - Injury risks for workers (Hammad 2019) 96
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
96
Figure A1 3 - Co2 amount (Aye 2011) 97
Figure A1 4 - Total project cost (Balasbaneh 2020) 97
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
97
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter) 98
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020) 98
Figure A1 8 - Co2 emission (Aye 2011) 98
Figure A1 9 - Injury risks for workers (Hammad 2019) 100
Figure A1 10 - Noise level (Hammad 2019) 100
Figure A1 11 - Greenhouse gas emission (Aye 2011) 101
Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo) 23
Table 2 2 - Possible benefits in projects scheduling 32
Table 2 3 - Economic benefits in modular method 35
Table 2 4 - Environmental Benefits 37
Table 2 5 - Health and safety amp Social-Laboral advantages 39
Table 3 1 - Participantrsquos profiles 50
Table 4 1 - Requirement tree with all indicators which considered for decision making process 67
Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed
to be done on them 68
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other
studied 68
Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow) 68
Table 4 5 - Qualitative indicators 69
Table 4 6 - First hand data over literature 69
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow) 70
Table 4 8 - First hand data over literature 70
Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue) 70
Table 4 10 - First hand data over literature 70
Table 4 11 - Final indicators for PCM 72
Table 4 12 - TRC first-hand data over literatures 72
Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow) 72
Table 4 14 - Final Quantitative indicators used for decision making process 72
Table 4 15 - Requirement weights 73
Table 4 16 - Weights of criteria 73
Table 4 17 - Value function for indicators in MIVES 76
Table 4 18 - Indicators normalized values 76
Table 4 19 ndash Indicator normalized values 76
Table 4 20 - Criteria normalized values 77
Table 4 21 - Criteria normalized values 77
Table 4 22 - Requirement normalized values for four indicators 81
Table 4 23 - SI (Sustainability Indexes related to four alternatives) 83
Table A1 1 ndash Cost of project PSM (Hammad 2019) 95
Table A1 2 -Time of project PSM (Hammad 2019) 95
Table A1 3 - Energy utilized during construction (Hammad 2019) 95
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 96
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 99
Table A1 6 6 - Projects cost (Hammad 2019) 99
Table A1 7 - Projects schedule (Hammad 2019 99
Table A1 8 - Energy utilised during construction process (Hammad 2019) 100
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011) 101
Table A2 1 - Professional experience of the company 102
Table A2 2 - Personal experience of participant 102
Table A2 3 - Type of modules 102
Table A2 4 - Type f projects 102
Table A2 5 - Characteristics of production range 103
Table A2 6 - Motivation for doing modular construction 103
Table A2 7 - Panel production conditions 103
Table A2 8 - Level of automation 103
Table A2 9 - Laboral status 104
Table A2 10 - Recycle and Re-use 104
Table A2 11 - Innovative technology integration 104
Table A2 12 - Automation status on waste generation 104
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table A2 13 - Reduction of waste 105
Table A2 14 - Energy consumption status 105
Table A2 15 - Delivery of projects in COVID-19 pandemic period 105
Table A2 16 - Aid organization project delivery 106
Table A2 17 - Post-sale services to client 106
Table A2 18 - Initial costs 106
Table A2 19 - Effective factors on initial costs 106
Table A2 20 - Re-use effect on budget 106
Table A2 21 - positive factors about modular construction to be chosen 107
Table A2 22 - Use of BIM in projects 107
Table A2 23 - Influence of production line on design 107
Table A2 24 - Lack of knowledge among experts 108
Table A2 25 - Transportation regulation effect on projects 108
Table A2 26 ndash Transportable material choice and its effects 108
Table A2 27 - Challenges of using automation 108
Table A2 28 - Contract condition in modular industry 109
Table A2 29 - Participation status in modular projects 109
Table A2 30 - Role of outside general constructor 109
Table A2 31 - Changes in production line and its effects 110
Table A2 32 - Site preparation status 110
Table A2 33 - Challenges with sub-contractors for site preparation phase 110
Table A2 34 - Wrong perceptions for modular products 110
Table A2 35 - Solutions for wrong perceptions 111
Table A2 36 - Recommendations 111
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
1 | P a g e
1 Introduction
Motivations
Construction industry is suffering for a poor productivity problem during the past 60 years in
comparison with other industries and industrialization in construction was suggested by the
investigators to improving the construction performance by applying production technologies and
design standardized products to be built in off-site plants By searching over the off-site methods
modular construction was found which is benefiting its high sustainability and productivity in
comparison with traditional construction approaches
One of the motivations of these study is to study the advantages of modular construction in
order to demonstrate the superior nature of modular construction over traditional methods to be
presented as a reasonable solution for productivity problem the However there are various of
opinions and argues about the beneficiary of this method so that it was decided to analyse them more
deeply in construction management perspective and even get into contact with the industry for
professional confirmation
Another motivation of this study was to contribute to development of modular construction
and find what is holding it back from developing by discovering the challenges in the modular
construction industry and find possible solutions to help for growth
Orientation of previous studies
During past two decades fewer studies in comparison with other innovative methods have
focused on this subject to analyse this method in economic environmental and functional areas to
discover the benefits and make comparisons with traditional construction methods where possible
McKinsey amp company report on 2019 had general overview on its potential advantages challenges
and its ability to raise the productivity in construction processes while introducing the benefits by
making comparisons in projectrsquos schedule budget and environmental performance among modular
and traditional methods and finally shedding a light on dark side which are the obstacles of growth in
industry and then suggesting possible solutions for improvements In addition there are numbers of
articles focusing on the environmental performance of modular buildings by doing Lifecycle
assessment (LCA) analysis on emissions waste generations and consumption primary resources etc
(Mohammad Kamali and Kasun Hewage et al 2016)
On the other side there are studies that made comparisons between traditional and modular
methods of construction to build a specific project based on BIM models and professional data bases
which led to great results that showed numbers of advantages (AWA Hammad et al 2019) (L Aye
et al 2011) (Ali Tighnavard Balasbaneh at Springer-Verlag 2020)
Gap of knowledge
Taking into account of existent researches there is a gap of knowledge which leads to few
questions that still have remained without answer
bull Confirmation of these benefits that came from scientific researches by professional
players in the industry
bull Do these advantages effect the final decision to choose modular method over
conventional way
bull What are the needs of the market that could be as motivations to use modular
construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
2 | P a g e
bull What are the challenges in the industry in the professional point of view
bull Do the solutions that suggested by researchers can be applied in real projects What
are their professional solutions
Objectives of the study
The importance of this study is to resolve the mentioned questions by accomplishing the
studyrsquos objectives that are separated to be achieved by two methods which are qualitative and
quantitative
Survey among the professionals in the modular industry by Online Form
bull To confirmcorrect the data from literature reviews about benefits of modular
construction
bull Their motivations and reasons to choose modular method
bull What are the constraints and obstacles that they are facing
bull Recommendations and solutions for these problems
Decision-making among three modular methods and conventional option by MIVES
bull To discover the advantages in real study cases by comparisons between four
alternatives
bull To examinate the functionality of every alternative in several criterions
bull How much effective these benefits can be in the final decision based on the
requirements of market and their priorities
Limitations
Several obstacles were seen during the study that effected the methodology and input data
significantly Here are some examples
Lack of existence of references related to the subject
Because of the subjectrsquos novelty or less focus the quantity of references is not enough to
cover all the dimensions of study therefore few estimation hypothesis (that were proved by the
results at the end) and consultants with experts were used instead to provide the necessary
information In addition many of the scientific reports and articles were published few months or
even days before the studyrsquos conclusions so that it was decided to be used immediately to improve
the studyrsquos liability
Non-accessible information from companies and scientific articles
There are innovative companies that because of their privacy policies and protection of
innovation could not provide the necessary data about their projects by request even for academic
uses
On the other side scientific papers in some cases were protected and did not have open
access not even with educational access permissions as requests have been denied by the authors
Obstacles caused by global lockdown during covid-19 pandemic
One of the unpredicted challenges that happened during the study was the virus pandemic
that affected the world negatively and this study was not an exception From on-site project and off-
site factory visits interviews with experts in the industry etc were cancelled Numbers of regions went
to full shutdown including offices factories etc which resulted in reduction of participations in online
survey form as well Therefore it was decided to select five most suitable participants to be analysed
instead of planed massive quantity of results
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
3 | P a g e
Organization of the thesis
⎯ Chapter two state of the art explaining the productivity problem history types and
phases of modular construction and literature reviews on benefits and challenges
⎯ Chapter three The online survey among modular players in the industry
⎯ Chapter four MIVES multi-criteria decision-making approach
⎯ Chapter five Conclusions and findings
⎯ Chapter six Recommendations
⎯ Chapter seven references
⎯ Anexo A (Input data references)
⎯ Anexo B (Survey QampA) 2
Kewwords Sustainability Modular construction MIVES Productivity rate Prefabrication Lifecycle assessment (LCA)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
4 | P a g e
2 State of the art Productivity problem in construction industry
Status of productivity rate of construction industry among other industries
It has been decades that construction industry is far behind the other industries in terms of
productivity rates Attempts had been done by innovative players in the industry but still the
difference is too enormous which the demands for improvement are needed
Globally construction sector labour-productivity growth averaged 1 percent a year over the
past two decades compared with 28 percent for the total world economy and 36 percent for
manufacturing If construction productivity were to catch up with the total economy the industryrsquos
value added could rise by $16 trillion a year (McKinsey 2019)
It can be said that the building industry is one of the key industries in the general economy
The construction sector typically comprises 8-10 of the Gross Domestic Profit (GDP) of a Western
economy (McGeorge amp Palmer 2002) Therefore only 10 improvement in construction
performance can represent a 25 increase in GDP (McGeorge amp Palmer 2002) Therefore there is
no doubt that improving productivity in the building industry will contribute positively to the general
economy
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The UK has a problem with productivity and the construction sector has poorer productivity
growth rates than any other Simply put productivity is the amount of stuff (whether goods or
services) that is produced by a person in an amount of time UK productivity is lower than it was in
2008 and the construction industry has not seen any significant growth in productivity in the last 20
years (Figure 22)
Figure 2 2 - UK productivity status (Office for National Statistics -ONS)
Not all the regions are struggling at the same rate and the reasons which will be discused
furthermore can be the insterest of regulators to support innovations and new solutions which can
improve the productivity in construction industry(Figure 23)
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS)
The result is that between 70 and 90 of projects exceed the original planned cost and that
the overrun commonly varies between 50 and 100 of budget Construction also suffers from 57
of effort on non-value-added activities compared with 26 within manufacturing (Figure 24)
These productivity rates had experienced severalrises and downs in some periods which is
because of increase of demandas of housing that results a boost in construction industry in order to
provide the needs
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Figure 2 4 - Value added comparison among industries (ennovacom)
Reasons of poor productivity
There are numbers of reasons for this poor performance The industry is extensively
regulated very dependent on public-sector demand and highly cyclical Informality and sometimes
corruption distort the market Moreover poor project management and execution insufficient skills
inadequate design processes and underinvestment in skills development RampD and innovation can
affect the productivity indirectly by decreasing the feasibility and value of the activities and add extra
costs on the project
Another key factor that causes a disruption among construction players which reduces the
average productivity rate is the lack of harmony in productivity between the players In other words
The sector divides mainly in two large-scale players involved in heavy construction such as civil and
industrial work and large-scale housing and a large number of firms engaged in fragmented
specialized trades such as mechanical electrical and plumbing work that act as subcontractors or
work on smaller projects like refurbishing single-family housing The first group manages to have 20
to 40 percent higher productivity than the second However even in the more productive heavy
construction sector there are endemic-potentially structural-challenges in meeting cost and schedule
commitments on megaprojects and players routinely subcontract specialized trades (McKinsey amp
Company 2019) (Figure 26)
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 6 - Fragmentations between construction industry players and their various productivity rates (McKinsey 2019)
Solutions for improvement
Nowadays there are solutions which are being used in construction world such reshaping the
regulation rewiring the contractual framework to reshape industry dynamics rethink design and
engineering processes improve procurement and supply-chain management improve on-site
execution infuse digital technology new materials and advanced automation and reskill the
workforce Each region based on their capabilities potential and Infrastructures would take a decision
which ways can be applied to increase the productivity in construction projects in a short or long
period
bull Redefine regulation Actions include streamlining permitting and approvals processes as
Australia has done reducing informality and corruption and encouraging transparency on cost
and performance as the International Construction Measurement Standards project does Many
governments allocate grants for innovation and training Germanyrsquos Federal Ministry of Transport
and Digital Infrastructure (formerly the Federal Ministry of Transport Building and Urban
Development) for instance supports RampD through studies in building materials Best practice
regulation would include moving toward outcome-based more standardized building codes and
consolidating land to promote scale Examples include Singaporersquos move to allow cross-laminated
timber (CLT) for high-rise structures and Japanrsquos promotion of scale through land pooling
bull Re-arrange the contractual framework Establishing a ldquosingle source of truthrdquo on projects for
monitoring progress early potentially supported by collaborative technology helps to minimize
misalignments and enable joint corrective action The data already exist to fundamentally
improve the accuracy of cost and schedule estimates Where players continue to use traditional
contracts they should introduce incentives that significantly improve performance and alignment
not at a trade or package level but at the project-outcome level To move toward best practices
appropriate alternative contracting models such as integrated project delivery (IPD) help build
long-term collaborative relationships Relational contracts will need to become more prevalent
than transactional contracts Sufficient investments in up-front planning incorporating all partiesrsquo
input have been shown to raise productivity substantially Smart Contracts are another example
of these solutions which during recent years is being identified by the major players A smart
contract is a computer program or a transaction protocol respectively which is intended to
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
8 | P a g e
automatically execute control or document respectively legally relevant events and actions
according to the terms of a contract of an agreement or of a negotiation The objectives of smart
contracts are the reduction of need in trusted intermediators arbitrations and enforcement costs
fraud losses as well as the reduction of malicious and accidental exceptions (Tapscott Don
Tapscott Alex amp Savelyev Alexander 2016)
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom)
bull Off-site production shift The biggest impact on productivity would come from moving toward
thinking about construction as a production system where possible encouraging off-site
manufacture minimizing on-site construction through the extensive use of pre-cast
technology assembling panels in factories and then finishing units onsite
bull Improve on-site execution There are four key approaches that are well known in the industry
but have not been universally adopted First is the introduction of a rigorous planning process
the Last Plannerreg System (LPS) is a useful tool to ensure that key activities are achieved on
time and on budget The use of integrated planning tools on a large-scale oil and gas project
for instance achieved a 70 percent increase in the projectrsquos productivity Second is reshaping
the relationship and interactions between owners and contractors and key performance
indicators (KPIs) being agreed on and used at regular performance meetings at which on-site
issues are resolved Complementing commonly used KPIs with additional forward-looking plan
conformance metrics to identify and subsequently reduce variance is critical Third is
improving the mobilization for new projects by ensuring that all pre-work (for instance
obtaining approvals and developing project milestones) has been completed prior to starting
onsite Finally there is a need for careful planning and coordination of different disciplines
on-site along with the application of lean principles to reduce waste and variability On-site
productivity can be increased by as much as 50 percent by implementing a cloud-based
control tower that rapidly assembles accurate data in near real time that is both backward-
looking and predictive (for example using plan conformance and other variability and
inventory metrics)
bull Introduce digital technology advanced automation Companies can start by making 3D
building information modelling (BIM) universal within the company alongside use of digital
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
9 | P a g e
collaboration tools drones and unmanned aerial vehicles for scanning monitoring and
mapping They can put themselves at the cutting edge by using platforms such as 5D BIM to
establish transparency in design costing and progress visualization (Figure 28)
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom)
Advanced analytics enabled by the Internet of Things to improve on-site monitoring of
materials labour and equipment productivity and digital collaboration and mobility tools (such as
construction management apps loaded on mobile devices) to better track progress and collaborate in
real time (Figure 29)
Figure 2 9 - Digital construction organization (wwwbimcommunitycom)
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Advanced automated equipment and tools such as bricklaying and tiling robots can accelerate
on-site execution The field of digital fabrication (dfab) is quite broad and has many applications Dfab
techniques are based on the combination of computational design methods and automated
construction processes which are typically categorized as subtractive formative or additive
(Kolarevic 2003) The use of subtractive and formative digital fabrication is becoming mainstream in
the prefabrication (off-site) of building parts (eg by using laser cutting CNC milling etc)
In recent years additive fabrication processes especially 3D printing have experienced a
rapid development in many industries As interest in additive fabrication grows research into large-
scale processes begins to reveal potential applications in construction (Labonnote et al 2016)
Existing additive dfab technologies can be classified in two big clusters on-site and off-site
construction technologies On the one hand on-site digital fabrication aims to bring additive
fabrication processes on construction sites
Sousa et al (2016) classified on-site technologies in three main categories large scale robotic
structures mobile robotic arms and flying robotic vehicles A well-known example from first category
is Contour Crafting a robotic structure for 3D printing large-scale construction developed at the
University of Southern California (Khoshnevis 2004)
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom)
bull Reskill the workforce Change in the construction sector cannot be achieved without
investment in retooling a workforce that is aging and changing its makeup through migration
Construction firms and workers need to continuously reskill and train to use the latest
equipment and digital tools In the mix should be apprenticeship programs such as the one
run by Siemens in the United Kingdom training frontline workers in core skills that are
currently underdeveloped and increasing stability in the workforce by breaking seasonality
and cyclicality
Brief on modular construction
History of modular construction
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bull 1800s
In 1830 he first documented prefabricated home was created by London carpenter John
Manning for his son who was moving from England to Australia Manning built a prefabricated house
in pieces then shipped it to the Land Down Under for easy assembly In 1840 Modular construction
made its way to the United States in response to the housing needs of the California Gold Rush The
Crystal Palace was built for Britains Great Exhibition and remains one of the most famous examples
of early modular construction in 1851 Designed in less than two weeks it utilized light and
inexpensive materials such as iron wood and glass it was constructed in only a few months
Afterward the palace was dismantled moved and rebuilt at another location
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom)
bull 1900s
Augustine Taylor a builder in Chicago devised the balloon-frame method (Figure 212)
enabling walls to be built offsite then transported to the intended construction site for speedy
assembly The rise of catalogue houses happened Between 1908 and 1940 when Sears Roebuck and
Co sold more than 500000 prefab homes through its catalogue straight to consumers At the time
these houses cost less than two-thirds of conventionally built homes and many still exist throughout
the United States
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull WWII Housing Boom
Prefab structures continued into World War Two to meet the growing demand for mass
accommodations for military personnel So-called Quonset Huts or Nissen Huts in the UK
comprised of corrugated steel were introduced for domestic military and institutional uses
When soldiers began returning home in the United States there was a need for rapid
construction for new homes to accommodate these expanding families Once again modular
construction serviced those needs because of its efficiency reduced costs and quick construction
Today many of those units are still in use
bull Prefab in Post-war Europe
The situation in Europe was more difficult although millions of people had no place to live on
the Old Continent due to the destruction of the Second World War people were unwilling to accept
prefabricated construction In Germany which had not only lost 25 percent of its entire housing stock
to bombing but also had to integrate 12 million refugees from former German territories in Eastern
Europe one form of prefabricated housing was used extensively the Nissen Hut (similar to the
Quonset hut) An attempt was also made in post-war France to combat housing shortages with the
help of prefabricated houses In 1944 Jean Prouveacute was already commissioned by the Ministry of
Reconstruction and Urban Planning to build 800 houses as emergency shelters that could be easily
disassembled However only 400 of these Maisons agraveportique which were equipped with an axial
steel frame were ever erected Prouveacutes Alba houses developed for the Abbey Pierres homeless
organization in 1956 were also not a success (Peter Goumlssel Arnt Cobbers Oliver Jahn 2012
architectureweekcom)
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8 meters (modulartch)
bull The Pre-fabulous 60s
The 1960s were a period of social transition in which attitudes towards prefabricated housing
also changed During this era which was marked by space travel the moon landing and even childrens
books that predicted weekend trips to distant galaxies prefabricated construction was discovered both
as a form of artistic expression and as a technical means of creating houses to provide a basis for new
lifestyles which seemed to be imminent in a society characterized by an extremely optimistic view of
progress
These approaches supported the idea of creating megastructures out of residential capsules
the architect Moshe Safdie who was only 24 at the time presented his megastructure Habitat 67 at
the Expo 67 in Montreal 158 housing units consisting of 354 concrete modules assembled as a
conglomerate
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The British architectural group Archigram developed building structures made of residential
capsules as an architectural Utopia which could be expanded at will and joined to form entire cities
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau)
bull Eco-conscious 70s
In 1972 the Japanese architect Kisho Kurokawa built the Nakagin Capsule Tower in Tokyo
housing cells were layered around a prefabricated concrete core to form a fourteen-story residential
tower(Figure 215) The idea of residential capsule megastructures was repeatedly revived as in Zvi
Heckers Ramot housing development in Jerusalem in 1974
The ecology movement of the 1970s brought an end to this euphoria regarding technological
progress and futuristic architectural dreams Now highly modern building materials that did not seem
to be in harmony with a return to nature such as plastic or aluminium fell into disrepute A new
perspective of view replaced as a priority to choose the material types which have the minimum
relation with non-renewable resources
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
bull 90s
This was further exacerbated by the fact that prefabricated elements had often been used to
build high-density housing which was now generally viewed negatively Hence prefabricated building
now came to be associated with the aesthetic and social failure of deindividualized megalomaniac
prefabricated slab housing blocks clustered on the periphery of large cities Thus the acceptance of
the prefabricated house in large parts of Europe remained low up until the 1990s
Prefabricated construction only gradually began to again emancipate itself from a homespun
cheap mass-produced image during the 1990s This is mainly due to the use of computer-operated
programs in the design and production processes The prefabricated housing industry now stands at
a juncture reminiscent of the dynamism of the 1920s and 1930s
bull Modern days
For many years now companies like Muji in Japan or BoKlok in Scandinavia and more recently
also in Poland and England have been supplying prefabricated houses in large numbers In Sweden
alone with only nine million inhabitants 14000 units are sold every year Muji offers models designed
by Kengo Kuma and Kazuhiko Namba that are as simple as they are elegant and far more interesting
than the building-kit houses offered by the multinational concerns Mitsubishi Toyota and Panasonic
(deluxemodularcom 2019)
Countries around the world have enlisted prefab and modular construction methods for
decades For example an estimate of all detached homes that are prefabricated in each country
shows a potential for growth off 84 in Sweden 5 in the United States 9 in Germany 20 in the
Netherlands and 28 in Japan
Today prefabrication and modularization are utilized in the construction of hotels apartment
buildings offices hospitals and schools in every major US city Here is a rundown of the percentage
per industry of prefabricated structures that use some form of modular construction
(deluxemodularcom 2019)
bull 49 of healthcare facilities
bull 42 of college buildings and dorms
bull And 42 of manufacturing buildings
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Types of modular product
Module architectural types
The products can be categorized by its functions dimensions material or type of its operation
etc Here they will be introduced by their general characteristics
bull Bathroom pods
Bathroom pods are commonly used in the construction of most hotels and apartment
buildings these days and becoming used more for residential housing The main drivers for choosing
a modular pod method are
o The cost savings that can be made by building repeated designs in a factory
environment
o Higher quality finish
o Rapid installation
o No trades on site
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom)
Pod Construction Process can be various but the most common steps can be as below
(httpswwwhowickltdcom)
Once the bathroom specification has been finalized and the design completed the
machine files are issued and the framing can be produced
The frames are rolled out of the machine ready for assembly
The panels are assembled
The panels are then fitted with the internal boarding and finished with tiles or a
waterproof lining
The walls floor and roof are joined to create the room structure and the joints sealed
The fixtures and fittings can then be installed including
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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o Bath or shower
o Toilets
o Basins
o Lights
o Mirrors
o Cabinets
The plumbing and electrical components are connected
The pods are then subjected to an electrical test and a pressure test to ensure there
are no leaks (Figure 217)
The pods are then sealed to prevent access ready for transportation
Once on site the pods are slid into position and connected to the power and water services
This process greatly reduces the build time as there are no requirements for trades on the site As the
pods are sealed until the building is completed there are reduced chances of them being damaged
during the building construction phase
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom)
bull Kitchen pods
These pods are less common but are also becoming more frequently used All the appliances
and electrics can be fitted in the factory removing the need for work on site Kitchen pods are ideal
for renovating older or industrial buildings as all the electrical services for the building can be
integrated into the pod From student accommodation to residential flats modular kitchen pods are
suitable for a variety of different sectors and uses and because they are designed bespoke to each
clientrsquos exact specifications they can be anything from a fully fitted kitchen to a small kitchenette
Each modular unit is completely customisable from the worktops to the splashbacks and integrated
white goods
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Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom)
bull Volumetric and modular rooms
Volumetric and modular rooms are becoming widely used for buildings that have a repetitive
nature Common structures include
bull Hotels
bull Apartments
bull Student accommodation
bull Schools
bull Hospitals
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The benefits of being able to manufacture the complete unit in the factory (including the
bathrooms and fitting of furniture) are
o No weather delays
o Superior finish quality
o All the electrical and plumbing works are done in a controlled atmosphere
o The rooms are sealed before moving to site restricting unauthorized access
Modular rooms production process can be explained as below
Once the building design has been completed and the individual modules specified the
framing components can be made on a just in time basis for site delivery
A typical assembly process would consist of
The floor cassette is rolled and the flooring boards are attached along with the
required insulation and services
The wall and ceiling frames are assembled
The internal lining is fitted and painted
The wall frames are then attached to the floor cassette (Figure 220)
Figure 2 20 - Production steps of floor cassette to walls and their attachment together (wwwhowickltdcom)
The ceiling frames are then fitted
The bathroom can then be fitted and plumbed as well as the electrical fittings and
wiring
The wall and ceiling insulation is added to the frame
The fit-out can then be completed to the desired specification
A hotel module for example would feature carpets bed bedside furniture desk
wardrobe TV system air-conditioning (either vents from main system or stand-alone
unit) bathroom fittings and fixtures
Once completed the electrics are checked and the plumbing is pressure tested
A protective cover is then added for transport and the unit is delivered to site
On-site the units are craned into position and joined
The services are connected
The building is then roofed and clad to the required specification In some cases the cladding
can be fitted during the module assembly further reducing the on-site work
bull Modular Trailers
Outside of modular homes modular trailers are probably the type of modular building that
people are most familiar with These buildings have a lot of applications and are often used as a
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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temporary space solution These trailers can be relocated for several times and are well-equipped as
well Temporary pre-semester school classes and temporary offices can be two examples of these
trailers uses
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom)
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom)
bull Containers
When looking at modular containers they are structures that are typically used to contain a
shiprsquos cargo When Shipping containers were originally created they were designed with modularity
in mind They were required to withstand all kinds of abuse as they journey through some of the
worldrsquos harshest climates From salt water to freezing temperatures a shipping container is meant to
handle the worst of the worst while protecting some of the worldrsquos most precious cargo Comprised
of Corten steel it is in a shipping containers DNA to protect itself from any corrosion or rust and when
they fall off the ship they can take up to a week to sink With more boxes being imported than
exported we have an opportunity to reuse something that is desperately looking for a new home
There has been a shift recently where after these buildings serve their purpose as shipping containers
they are reused fitted with windows doors HVAC units etc And made into an office environment
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The biggest benefit of these containers is they are cheap very portable and easy to install on site
However since most of the time these buildings are retrofitted and remodelled into modular
buildings they usually do not have a lot of flexibility in layout or their dimensions
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom)
Shipping containers act as the exoskeleton of each module The original structure will frame
the HVAC wiring lighting plumbing appliances and wall finish materials Because containers were
built to be durable and mobile they can be transported by train tractor-trailer boat or in some cases
a powerful pickup truck Forklift pockets and corner castings allow the containers to be moved smaller
distances by crane and forklift Shipping containers empower you to move your modular structures
without sacrificing the structural integrity or damaging the modulersquos contents
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom)
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bull Office Complexes
Office complexes will take several office modules and combine them to assemble a much
larger fully functioning office building Just like all modular construction these modules are
fabricated in a manufacturing environment except when these projects reach the job site they
function more similarly to a full-fledged construction site Generally the module will need a crane to
lift the section from the ground and place it in the correct spot to assemble the building Next the
workers will go through that module and do all things necessary to attach and hook up the piece
Then the next piece is put in place and these steps are repeated and again until the building is
finished
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom)
bull Modular enclosures
For instance one of the major electric utilities in the Northeast using Modular Construction is
Wunderlich Malec Integrated Control Enclosures since 2001 A standard 16times50times11-foot enclosure
with twenty (20) protective relay and control cabinets marshalling cabinets HVAC fire and security
completely installed wired and tested at the factory prior to shipment
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-Malec (wmengcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Module structure types
Modular structure types can be categorized by their materials or structural formation
o Steel Modules
bull 4-sided modules
In this form of construction modules are manufactured with four closed sides to create
cellular type spaces designed to transfer the combined vertical load of the modules above and in-
plane loads (due to wind action) through their longitudinal walls The cellular space provided is limited
by the transportation and installation requirements Depending on location and exposure to wind
action the height of buildings in fully modular construction is in the range of 6 to 10 storeys Modules
are manufactured from a series of 2D panels beginning with the floor cassette to which the four wall
panels and ceiling panel are attached generally by screws The walls transfer vertical loads and
therefore the longitudinal walls of the upper module are designed to sit on the walls of the module
below
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo)
It consists of a modular structure of high strength galvanized steel which is also used as the
basis for building closure Steel physical properties make it one of the most versatile materials for
construction since it is
ELASTIC Steel does not break as it has a great strength and elasticity It is easily workable and it has
a great advantage over traditional construction
RECYCLABLE Steel is 100 recyclable
DURABLE With zinc application it can become galvanized steel which has extraordinary durability
properties
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Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo)
bull Partially open-sided modules
4 sided modules can be designed with partially open sides by the introduction of corner and
intermediate posts and by using a stiff continuous edge beam in the floor cassette The maximum
width of opening is limited by the bending resistance and stiffness of the edge member in the floor
cassette Additional intermediate posts are usually square hollow sections (SHS) so that they can fit
within the wall width
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull Open sided (corner-supported) modules
Modules may be designed to provide fully open sides by transfer of loads through the
longitudinal edge beams to the corner posts The framework of the module is often in the form of hot
rolled steel members such as Square Hollow Section (SHS) columns and Parallel Flange Channel (PFC)
edge beams that are bolted together
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported module
(wwwsteelconstructioninfo)
bull Modules supported by a primary structure
Modular units may be designed to be supported by a primary structure at a podium or
platform level In this case the supporting columns are positioned at a multiple of the width of the
modules (normally 2 or 3 modules) The beams are designed to support the combined loads from the
modules above (normally a maximum of 46 storeys) The supporting structure is designed
conventionally as a steel framework with beams and columns that align with multiples of the module
width and provides open plan space at ground floor and below ground levels This form of construction
is very suitable for mixed retail commercial and residential developments especially for residential
units above commercial areas or car parking etc particularly in urban projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the lower levels
(wwwsteelconstructioninfo)
o Wood structure
Back in the days of the very first modular buildings wood was the modular construction
material of choice and nowadays it overwhelmingly remains the most used for these projects due
to its abundance and cheaper initial costs Wood-framed modular buildings however have several
notable limitations that might give a property developer pause and may even prove more costly in the
long-term repairs
Wood often lacks the strength necessary to support large building projects especially those
of multiple stories Due to this weakness wood-framed buildings are typically no taller than a few
stories a considerable limitation for someone looking to build a hotel or apartment building as
examples
Wood is flammable and vulnerable to fire which could severely damage the structural
integrity of the building requiring replacement or even worse leading to a total collapse
Wood tends to warp over time resulting in a lower quality building in the years after
completion Combined with its susceptibility to pests and mold selecting wood for a modular
structure may prove to be the more expensive choice in the long term considering repair costsmdasheven
despite initial savings
Wood is among the most wasted materials used in modern construction On average 20 of
construction lumber typically ends up in landfills leaving a larger environmental footprint than other
alternatives (httpswwwdeluxemodularcom)
Considering all those negative points mentioned earlier there are numbers of regions that
still are oriented to wooden structures as this type of housing is part of culture of the society because
of traditional architecture etc therefore typical clients prefer to build the type of accommodation
that they trusted for many years as it became the main demand of market Accessible local resources
availability of necessary knowledge for construction and compatibility of labour forces with this
method are other reasons to be chosen over the other alternatives
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other metals
(vanguardmodularcom)
o Concrete modules
Precast concrete is a well-established and efficient manufacturing industry and products
range from hollow-core slabs to beams and columns in structural frames Concrete modules can be
manufactured in two ways either from precast 2D wall floor and ceiling panels or as 3D modular
units which are generally cast with an open base Concrete modules are often used in high-security
applications as they are extremely resistant to damage
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma Beton)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Types of modular buildings based on operation period
bull Relocatable Buildings (RB)
Relocatable modular buildings are designed to be reused or repurposed multiple times and
transported to different sites Relocatable Building as defined in the 2015 International Existing
Building Code a partially or completely assembled building constructed and designed to be reused
multiple times and transported to different building sites
bull Permanent Modular Construction (PMC)
PMC is an innovative sustainable construction delivery method utilizing offsite lean
manufacturing techniques to prefabricate single or multi-story whole building solutions in deliverable
module sections PMC buildings are manufactured in a safe controlled setting and can be constructed
of wood steel or concrete PMC modules can be integrated into site-built projects or stand alone as
a turnkey solution and can be delivered with MEP fixtures and interior finishes in less time with less
waste and higher quality control compared to projects utilizing only traditional site construction
Common uses of modular buildings in the market
o Education
Relocatable buildings have become a critical factor in managing student demographics and
increasing enrolments Relocatable classrooms are also ideal for swing space during new construction
or renovation Convenient flexible cost-effective temporary buildings can be delivered and
operational in as little as 24-hours These classrooms are measured for quality and code compliance
by state or third-party agencies through routine and random inspections testing and certification
services Customers may choose single classrooms or arrange multiple buildings in clusters to create
a campus feel MBI members supply steps decks ramps and even furniture Members also offer
lease purchase and lease-to-purchase financing for a variety of public and private school needs
These classrooms are sometimes referred to as temporary portable or mobile classrooms
o Construction-Site
Relocatable buildings have their roots in construction site trailers where speed temporary
space and relocate-ability are important Used as standard field offices construction site and in-plant
buildings are available for immediate delivery Standard construction is wood but steel units are
available to meet non-combustible requirements In-plant buildings are available as single- or two-
story units for industrial environments with noise reducing insulation and are typically moveable by
forklift and include electrical and communications wiring heating air conditioning and even
plumbing
o Healthcare
Relocatable buildings for healthcare applications are designed and constructed to
uncompromising standards of quality A customerrsquos new clinic hospital extension laboratory
diagnostic centre MRI unit dentist office or other medical facility can be open for business and
serving communities in as little as a few days Is your interest in serving patients as quickly as possible
in the safest and aesthetically pleasing environments available These facilities offer quick quiet safe
and clean buildings with an unlimited choice of interior deacutecor and furniture and equipment leasing
o General Administrative and Sales Office
When production demands increase relocatable buildings can temporarily enlarge a current
facility without permanent alterations to the site Because the space is not permanent many
companies are able to expand without the budget approval process necessary for traditional capital
expenses Relocatable offices can be single- and multi-story buildings configured to include
independent offices conference rooms and large open spaces for cubicles or other partition systems
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
28 | P a g e
Large and small businesses as well as local and state governments are typical users of relocatable
office space
o CommercialRetail
Earlier occupancy means quicker return on investment For retail occupancies this can mean
significant cash flow advantages Standard floorplans are available for immediate delivery while
custom buildings are built to specifications in weeks not months Unique to the modular process is
concurrent construction site-work occurs while buildings are being put together in a quality-
controlled factory Typical retail applications include new home sales centers banks golf pro shops
automobile fleet ownerships college bookstores and concession stands If a clientrsquos emerging
business needs are short-term temporary space will accommodate their financial situation space
requirements and deadlines
o Security
Relocatable buildings can be custom built for a variety of access and control situations Toll
booths tickets sales offices guard stands and weigh stations are common applications One and two-
story wood and steel buildings have straight walls or walls that are tilted to improve views and reduce
glare
o EmergencyDisaster Relief
There is simply no other means of providing fast transitional shelter and basic community
needs following natural disasters than relocatable buildings Relocatable buildings can be quickly and
efficiently deployed for emergency shelter medical and educational needs or to accommodate relief
workers
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction report MBI 2019)
Construction phases
Modular construction is the process of manufacturing multiple building sections in a facility
for assembly at a remote building site The building sections called modules will fit together once
assembled on site with plumbing HVAC and electrical connections running throughout One of the
great advantages in the modular construction process is that many of the processes happen at the
same time which can cut the construction time in half There are six common steps to complete a
modular project Design amp Engineering Permits amp Approvals Site Development Plant Fabrication
Transportation and Installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
29 | P a g e
Figure 2 34 - Overlaps of phases in modular construction project
o Step 1 Design
The design phase of the modular building process creates a description of the building usually
represented by detailed plans and specifications A thorough customer consultation with a Palomar
project manager gathers the information required to develop the building plan Once this information
has been gathered the design team will produce the ideal modular building design to fit the customerrsquos
needs
o Step 2 Engineering
Each building design goes through the engineering department for an engineering review Like
site-built structures modular buildings are subject to a series of national state and local building
codes that ensure the building meets a set of standards for safety and performance State level
building codes can be superseded or augmented by local building code requirements and then must
confirm the design proposal meets all applicable building codes
o Step 3 Permits amp Approvals
A construction permit or building permit is a permit required in most jurisdictions for new
construction or major renovations Typical construction permits required can include
Site plan
Building permit
Mechanical permit
Plumbing permit
Concrete permit
Encroachment permit
Sign permit
Flood district development permit
The building owner is ultimately responsible for securing building permits for work on their
property In practice most building owners appoint the general contractor as an authorized
representative so the contractor can obtain the required permits The building owner is advised to
confirm that the general contractor has secured the proper building permits for their project Failure
to obtain the proper permits can result in significant fines penalties and even demolition of
unauthorized construction
o Step 4 Site Development
One of the advantages inherent in modular construction is that the site development and
building foundation are prepared while the modules are being fabricated at the manufacturing facility
and transported to the job site The site development and building construction processes happen
Permits
Design amp Engineering
Site Development
Plant Fabrication
TransportationOn-site installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
30 | P a g e
concurrently instead of sequentially like site-built construction Projects are developed on a variety of
geographic settings typical site development includes
Surveying
Demolition
Excavation
Grading
Site drainage
Foundation construction
Utility installation
There are two primary modular building foundation classifications on-grade and raised or full
foundation An on-grade foundation is generally for permanent installations and is more expensive A
full foundation can be used for temporary or permanent structures it is less expensive to install and
it is more cost effective to relocate the building later while causing minimal site disturbance
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom)
bull Step 5 Plant Fabrication
There are two scenarios for steel modular constructors There are few numbers of off-site
plant which built their own steel frames inside the plant because of high initial budget and it is
common that it would be cheaper to order the frames from another supplier and transfer to the
factory to assembly with other parts The steel frame is then loaded on the main factory production
line where the sub-floor is insulated and floor decking is assembled atop the steel frame As the
module moves down the production line framed wall sections are fabricated insulated and hoisted
in place The truss roof assembly is built in components at ground level before it is hoisted into place
The module proceeds down the line where mechanical electrical and plumbing services are installed
while the last of the insulation goes into place Interior finishes like drywall painting and flooring are
applied while doors and windows are installed
On the last stop of the production line the exterior finish and trim are applied before the
module is prepared for transportation
During construction at the manufacturing facility a third-party inspection agency is present to
ensure the modules are built in compliance with building code
bull Step 6 Transportation
The fabricated modules are shipped over the road by carriers that specialize in modular
building transportation In most US jurisdictions building shipping limitations are 16rsquo in width and
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
31 | P a g e
between 70rsquo amp 90rsquo in length per module Permissible Maximum Dimensions of Lorries in Europe and
UK for Lorry or Trailer are 4m in height 255m in width and 12m in length (International
Transportation forum)
bull Step 7 Installation
A general contractor often one specializing in modular construction will install the modules
complete any on site finish out and make the final utility connections
The choice of building foundation determines how the building will be installed Permanent
semi-permanent and on grade foundations will require the modules to be set with a crane Raised
foundations typically used for temporary buildings allow the modules to be set in place through
simple mechanical methods
With the modules in place final finish out of the interior and exterior proceeds Finish out can
include electrical and mechanical system connection between modules stairs wheelchair ramps
skirting exterior siding trim and utility connections
Literature review on possible advantages
Modular construction comes with advantages which motivates investors and innovative
constructors to apply this method on their future projects Here these benefits are being classified in
various sections such as schedule economic environmental health and safety and social-laboral
advantages
Scheduling benefits
While on-site constructors are complaining about the slow progression of construction
activities and delays on project deliveries the struggle is still to be continued to find new methods to
improve productivity and progression speed while maintaining the quality at a reasonable level
whether if its achievable or not On the other side modular construction because of numbers of
reasons is making a significant boost in term of time management in many phases As it can be seen
in figure 236 McKinsey amp Company report explains that approximately between 20 - 50
scheduling improvement can be achieved in comparison with traditional on-site construction
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method (McKinsey amp Company
2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
32 | P a g e
To be more specific literature reviews identified numbers of benefits in most of the
constructive activities from design to on-site installation As the table 22 illustrates off-site
manufacturing brings most of the time saving to the project by better coordination precise quality
management and not being affected by the on-site bad conditions Table 2 2 - Possible benefits in projects scheduling
In addition design can the ability to be applied in multiple projects instead of just one which
accelerates the project schedule significantly Various overlaps in modular construction can save lots
of time in projects such as site preparations off-site manufacturing and on-site installation with each
other
The acceleration in design process which would be ideal for schedule-critical projects (for
instance emergency accommodation for people who are affected by natural causes) also Long-lead
items can be stocked Fabrication can start and finish earlier in this case In the real state point of view
in the design phase there is one huge benefit which will be so handy when nearly ldquoshovel-readyrdquo
design documentation is needed for clients and site selectors (wwwmcminnvillebusinesscom)
The simplicity precision and clarity of the design plans in modular projects can increase the
possibility of using advanced software such as BIM which reduce the period time of designing phase
significantly With the increasing the possibility of integration of BIM in construction project
incorporating modular building technologies into project becomes more developed and
manufacturing and construction process could be streamlined (Na Lu and Thomas Korman 2010)
About 90 percent of the build activity takes place indoors which means the building process
is nearly guaranteed to stay on schedule That predictability and reliability enable you to count on
timely project completion If a skilled modular crew only spends half the time building your structure
than a site-built crew would your labour cost also gets cut in half
Because of stability of production location there are numbers of advanced technologies
which are being used in other industries production lines that can be used in these off-site facilities in
order to improve the productivity and reduce the timeline of the activities
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
33 | P a g e
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom)
The nature and outdoor construction have always mutual effects on each other mostly in a
disfavour way Site conditions often cause negative impacts on the activities which lead delays quality
insurances or stop them because of safety matters In result the project schedule can be changed and
most of the times unpredictive delays will take place in the timelines In addition there are sites which
the possibility of on-site construction for most of the year is almost zero percent or if exists would be
limited because of life risks for workforce A reasonable solution for these cases is off-site construction
which in most of them reduce the nature effects Thus factory-based production can make a
revolutionary impact on the project scheduling In modular method 60-90 of the construction work
is completed in a closed factory environment and this mitigates the impact of unfavourable weather
(FLORI MURESAN on ny-engineerscom)
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
34 | P a g e
Machinery equipment can take place in mentioned phase instead of human labour which can
boost the productivity quality as well as the time reduction Robotic assembly is one the efficient
examples of this technology One of the very first EU projects carried out in the Robotics Lab
(httproboticslabuc3mes) located at the Carlos III University named FutureHome-IF7 project The
done research was focused in the robotization and industrialisation of the final stage of the
construction process by mean of modular construction (Martinez 2008)
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes)
Economic benefits
Economic advantages can always attract investors to develop innovations Since in a project
time and cost have a direct and mutual relation with each other most of the benefits which were
mentioned earlier in the schedule section can also make positive impact in projectrsquos economy In
some cases these benefits equal to the initial costs which will be discussed later in challenges As it
was mentioned earlier the design plans can be repeated multiple times in projects because of
similarity of requirements that can save design costs in future budgets
Modular building because of their standardization and classification in design phase can be
more compatible with advanced such as BIM (building information modelling) BIM technology in its
5D phase does cost estimating material quantifications and pricing to be automatically generated
and modified while changes are applied for each building module (Na Lu and Thomas Korman 2010)
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
35 | P a g e
Foundations do not have complexity in modular buildings because of weight of the modules
which have to be manufactured lightly in order to be transported simpler to the location
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk)
Also because of the high quality and precise off-site execution there are fewer reworks in
modular products which can save costs in projects Off-site manufacturing provides more economic
benefits such as reduction of salary wages due to a smaller number of workers and more specialized
ones and adding values to each hour of work by increasing productivity to the activities
Moreover massive orders of Materials to the supplier can bring more quality to the material
multiple discounts on each offer and add more stability in prices of material in instable markets Table 2 3 - Economic benefits in modular method
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
36 | P a g e
Environmental Benefits
A highlight among the modular constructionrsquos benefits is in the environmental point of view
Since the modular buildings are friendly with environment many clients are willing to change their
method to this ecological approach in order to make their projects more sustainable and promote
their product in the market as an innovative constructor in the industry such as ldquoGrupo Consentinordquo
which not only builds modules that are available to use solar panels as energy supplier but recycle
many structural and non-structural elements and reuse them in another projects Waste management
can be applied simply in modular construction by reduction in waste during off-site production recycle
and reuses in elements in several projects use of automation can secure waste reduction at a high
rate It has been proven that modular construction can reduce waste by up to 90 thanks to off-site
construction (JAHNAVI SAJIP ny-engineerscom)
Agostinho Mendonccedila in 2018 did a research about reuse in construction industry which
shows a great improvement in terms of sustainability During 2022 FIFA World Cup in Qatar football
fans will have the opportunity to enjoy the stunning views of Doharsquos skyscrapers and be marvelled at
the unique Ras Abu Abod Stadium Its design concept results in a good cost-efficient arena with an
elegant curved square form
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images)
This innovative stadium will also allow it to be completely disassembled after the World Cup
Precisely many elements of the arena including all 40000 seats the containers and even the roof
will be reused providing valuable infrastructures to sports and non-sports projects elsewhere
Moreover off-site manufacturing can reduce emissions much more than conventional
method In 2009 Al-Hussein et al focused on the construction phase of modular and conventional
buildings and compared their CO2 equivalent emissions They analysed a 42-suite multi-family four-
story residential modular building located in Alberta Canada All the construction activities needed
for this building and a similar conventional building such as material delivery transportation
workforce trips equipment usage and winter heating were identified separately Therefore CO2
emissions from each of these activities were quantified The authorsrsquo analyses showed that modular
processes led to a 43 reduction in CO2 emissions compared to on-site processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
37 | P a g e
Table 2 4 - Environmental Benefits
While the on-site construction disturbs the sitersquos neighbourhood with noise dust congestion
and waste modular construction performs better by providing minimal project site disturbance
(Mohammad Kamali2016) Since most of the construction process takes place offsite there is less
impact on the project surroundings Modular construction reduces the number of vehicles and heavy
equipment required on site which translates into reduced pollution and less site disruption
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site (wwwcadoltocom)
Energy consumption in the occupancy phase of modular buildings dominates the other life
cycle phases This phase alone accounts for more than 70 and up to 98 of energy consumption and
consequent impacts over the life cycle of buildings while the contribution of the construction phase
is relatively small (M Kamali 2016) Sustainable material selection optimum modular factory
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
38 | P a g e
location and availability of labour which lead to less embodied energy consumption are effective
opportunities to reduce the life cycle energy consumption and the subsequent environmental
impacts In addition a smart design of insulation which is advanced in modular buildings can achieve
a high amount of energy use saving during the operation phase
Figure 2 44 - various layers of a module building unit including insulations (wwwsteelconstructioninfo)
Health and security benefits
When it comes to safety modular method can offer advantages for both phases (construction
and operation) to workers and future users Converting possibly dangerous on-site activities to an off-
site plant that there the supervision and control is much higher can reduce the accidents for the
workforces and the products It is obvious that the safety plan can be applied much more efficient in
a factory environment Not only is there a reduced risk of slips trips and falls ndash particularly as work
at height is reduced but there is also a reduction in onsite activity thus ensuring health and safety
always remains a top priority from start to finish
Furthermore if necessary factory operations can continue 247 with less risk of noise and
disruption to workers Work is also unaffected by the weather and other environmental delays which
could result in the project being turned around even quicker
On the other side during the operation phase safety can be improved for instance fire
protection can be designed by using multiple insulations and protectors inside the panels
One of the examples is Actavorsquos plan for Ensuring everyonersquos safety is at the heart of Actavo
what does and in line with this they have developed the HEART (Help Eliminate All Risks Today)
procedure Devised and implemented in the continuous effort to create an accident and incident-free
environment the HEART behavioural safety observation process sets the whole Actavo teamrsquos
expectation every injury is preventable so do not let any happen (Hannah Vickers b4edcom)
Modular construction generally achieves these requirements using fire-resistant plasterboard
conforming to BS EN 520 Alternative materials such as cement particle board and gypsum fibre board
may also be used in combination with plasterboard as the facing layer In residential construction
each dwelling usually forms a separate fire compartment All walls and floors that provide a separating
function between compartments require 60 minutes fire resistance In hotels and other residential
buildings each bedroom may form its own compartment (wwwsteelconstructioninfo)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
39 | P a g e
Figure 2 45 - Compartment floor at junction with external wall and compartment wall (wwwsteelconstructioninfo)
Social-Laboral benefits
Most of the mentioned benefits including economic scheduling environmental and safety
advantages have direct effect on social well-being as well Therefore they can also be named in this
section Future users can benefit from the quality of building energy savings etc which leads to
costumerrsquos satisfaction among the public Due to the shorter on-site schedule there are fewer
negative impacts on local businesses urban beauty image than conventional constructions Also
modular construction demands more skilled workforce and experts which can create more jobs for
these group of labour in the regions that struggle with high unemployment rates
In addition every industry needs to trust innovations in order to improve the science and help
the innovator to break limitations and explore new alternatives to solve problems Modular
construction as it was mentioned can be a great solution for the productivity problem in construction
industry and by applying these method it is possible to even find more solutions in the future which
can increase these rate more or solve other problems that nowadays are common among players of
construction industry Table 2 5 - Health and safety amp Social-Laboral advantages
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
40 | P a g e
Modular Construction role in COIVD-19 Pandemic
Recognizing the urgent need to create modular critical care units for rapidly growing numbers
of COVID-19 patients HGA Architects and Engineers partnered with Boldt Construction to design and
build a new system within a noticeably short timeframe ldquoThe initial idea was to provide rapid
response for hospitals and build a product with off-the-shelf readily available parts because we did
not know what the supply chain would be like Over the course of three weeks we went from concept
to full design and fabrication was underwayrdquo reports Ben Bruns executive vice president of Boldt
Construction in Appleton Wis (Rapid Response by Barbara Horwitz-Bennett 2020) The final product
was a prefabricated modular solution for assembling field hospitals capable of providing airborne
infection isolation rooms
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use inside convention
centres arenas and temporary structures Image courtesy of HGA and The Boldt Company (prismpubcom)
These Strategic Temporary Acuity-Adaptable Treatment (STAAT) units are isolation units with
enough clearance for safe bed transfers and accommodate equipment and a reclining chair These
multifunctional modules can be used as supplemental interior isolation rooms within an existing
system of care as a modular system connected to an existing hospitalrsquos infrastructure or as a self-
sufficient temporary hospital with its own infrastructure
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The Boldt Company
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
41 | P a g e
PCL Construction has come up with a similar solution in collaboration with Thor Plumbing and
Heating f-BLOK Architecture EH Price Industries and P4 Electrical Contractors Called ldquoQuaran-Tin
Podsrdquo the units are emergency response modular isolationcare rooms that provide temporary and
reusable emergency isolation for care and treatment of COVID-19 patients Each unit is self-contained
with built-in power heating and cooling as well as connections for medical gas oxygen and vacuum
Highly scalable and customizable the pod is continuously negatively pressurized and all the exhaust
is HEPA filtered Citizen Care Pod is a smart screening and testing pod that integrates intelligent
technology within a modular design to support a safe responsible recovery for governments
businesses and communities Customizable with the capabilities to enable full-on mobile COVID-19
testing in high-traffic environments the project will help in testing screening and eventually
vaccination on a mass scale (Christele Harrouk on archdailycom)
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction (archdailycom)
The Citizen Care Pod is a turnkey solution that accelerates recovery for businesses and public
institutions such as airports offices sports and entertainment complexes construction sites and
more by rebuilding staff and customer confidence that your organization is equipped to ensure their
safety
Unfortunately the COVID-19 pandemic is only intensifying the housing crisis Further
complicating the issue is the fact that a significant percentage of skilled labour workers will be retiring
within the next couple years which will significantly impact the construction industry As stated in
MBIrsquos ldquoThe US Construction Industry A National Crisis Loomingrdquo there are currently not enough
skilled workers to build all of the projects that need to be built in the same manner in which they have
been built in the past ldquoThere is no other choicerdquo advises Hardiman ldquoIt is now time for our
policymakers to start looking at alternative ways to build everything and we think that modular
construction should be a part of that solutionrdquo Along these lines the COVID-1 Response Page also
includes links to articles illustrating how MBI membersrsquo systems and facilities are currently being used
in housing infrastructure and COVID-19-related projects
Review on common challenges
Initial costs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
42 | P a g e
To start the modular construction method in an area there will be a significant investment
to establish a production plan and then designing team who must work alongside the execution
engineers parallelly in the design phase
factory cost Like any other industry modular construction demands a production line which
is an off-site plan with a supply chain based on 3D volumetric products First the off-site plan must be
designed based on the local requirements amount of demands availability of experts and labours and
budget that manufactures are willing to invest on this technology These factories are mostly
expensive to be build and the issue of production costs will always be a barrier to innovation in
modular construction because both the client and the architect will expect lower fabrication costs
However the art of every industrial innovative player is to study the economic pros and cons
of issued technology and then the industrial expert by doing couple trade-offs between the benefits
and disadvantages can make the decision whether to apply the new method or not Modular
construction is not an exception of this fact A local study can tell the investors if the approach would
be reasonable in all term and not only economic terms for the society or not Thus due to the
economic benefits that were mentioned earlier in numbers of regions which the labour salaries are
higher and the balance between transportation costs primary material access and costs experts
existence local market and their demand of real state and initial costs is more favourable modular
construction can be the best solution to apply On the other hand nowadays there are numbers of
region which the investors of industry are eager to use innovative method with higher costs that have
positive influence on environment and public health in which modular construction is more friendly
than the conventional method
Figure 2 49 -Balance between Initial costs and Economical benefits
First design costs and errors By changing the traditional construction products a change of
design is also demanded Modular design can be based by the production linersquos technologies the
budget of manufacturer and the final products quantity and quality In the earlier discussions about
design phase the complexity of 3D volumetric design had been mentioned and surely in the first
attempts would be expensive for the manufacturer However if the design could focus more on the
standardization of elements repetition in production line and consider integrate with modern design
software in order to provide more executive details and minimize the future errors and reworks the
rework cost can be eliminated and the design sample can be used for numbers of projects as a
catalogue with few changes Therefore by having these advantages the initial design cost can be
recovered soon and even make more benefit by the time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
43 | P a g e
Architectural challenges
One of the main group of experts who have argues about modular buildings are the
architectures who always suffer from limitations that this approach puts on their design process Most
of these challenges are mentioned below
bull Manufacturing technologies effect on the design One of the challenges which the manufacturers
can struggle is to consider a production line that be able to produce a wide range of product so
that there will be fewer limitations on the design phase This goal can often be impossible because
of the predicted budget of investors limited area of production plant and lack of technologies
Thus it is the architect who must be flexible with the production line and its boundaries
Moreover it is the art of the architect which can maintain a balance between ability of production
line and attractivity and innovation of the final product for the market and the industry
bull Transportation boundaries on architecture It is a fact that the transportation of modular
construction have puts limitations on the architectrsquos works The modules must obey the
obligations and regulations of the region that want to be transported in Therefore architects
must design modules which are transportable and minimize negative economic and timing effects
for the project In addition in the designing process environmental aspects which can be
happening during the transportation phase must be considered
bull Regional architecture specializations There are cases in which an off-site production plant ships
same model of modules for numbers of projects which are going to be assembled in variety of
regions with different climate cultural architecture and local construction regulations which can
surely have negative effects on the regionrsquos construction industry real estate market and cultural
architecture aspects For instance the harmony of the angel of sunlight and the windows
formation and dimensions in a residential building located in eastern region and western ones
which reduce or increase the sunlight absorption inside the building for the residents In this case
if the same form of modules will be transported and assembled without of any changes the
unsatisfaction of future users can be increased and in a result the demands can be reduce
significantly which could cause a failure for the real estate and construction industry of the region
In terms of architectural culture modular manufacturers must consider the traditional
architecture of the location in the designs in order to make sure that the harmony will be kept
among the present buildings and modular ones
bull Lack of knowledge about modular buildings among architects Manufacturers argue about the
lack of enough knowledge of architects about the modular fabrication process The third-party
inspections and approval process Transportation methods and its boundaries Onsite assembly
procedures The cross section of a modular structure which can reduce their understandings from
manufacturerrsquos demands of project and result a unsuitable design for the final products These
disagreements come with every innovation in civil engineering society which architect must follow
their lead most of the time The solution for this cause is to educate the architects by planning
workshops by the manufacturers or internships during a project so that architects can improve
their knowledge and gain actual experiences by observe and participating in real projects
bull Unfeasible on-site finishing Common architectural innovative designs focus a lot on finishing
works in order to gain attentions of buyer and improve attractiveness of buildings There are
different views about this subject Some manufacturers think that the finishing process must be
as simple as possible or minimize the schedule and costs on-site to benefit from the project On
the other hand architects believe that the modular buildings are not attractive enough because
of repetition in their design and try to focus on finishing process to make them desirable to the
market or improve the products in architectonic point of view
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
44 | P a g e
Transportation challenges
By transferring most of the construction activity to the off-site plant transportation plays a
vital role in the projects so that in case of poor logistic management can damage numbers of benefits
which were achieved in the factory plant
bull Dimensional and weight barriers based on type of transportation The type and technologies of
every modular constructorrsquos logistics can affect the project from the design phase to the on-site
assembly These effects can change the dimensions weight and structural features of the product
For instance modular structures transported on a flatback trailer will be limited in length width
and weight based on the physical capacity of the truck Components fit into shipping containers
are best suited for projects overseas because the structural integrity of the containers allows for
unorganized stacking However components will be limited by the interior dimensions of the
container in length width and height (Joseph M Schoenborn 2012)
bull Long distance transportation and lack of existence of local factory Off-site plants are not
available for every site location in numbers of states or even regions yet because of poor
development of these method in those regions Therefore in some cases the modules must
shipped even overseas to the site location to be assembled Long distance and its possible
difficulties during ground or marine transportation can bring extra costs for the project which
must be studied economically before the biding process
bull State regulations on structures dimensions and strategic issues Estate laws can always put
boundaries on construction industry and modular constructors are not an exception Every region
has its structural and transportation regulation which limits the final product In addition estate
approval during transportation phase can harm the projectrsquos scheduling program and put delays
on the arrivals or even occasional penalties which causes extra costs in the budget
bull Negative effects from environment on the modules during the transportation While the
modules are being transported to the site these products are in direct exposure to the
environment such as sunlight rain wind and other natural causes By the time possible damages
can be appeared in the modules which in some cases can be too critical that module need to be
repaired or replaced to be used On the other hand ground transportations can cause vibrations
on the trucks and its loads and the intensity of damage generally increases with the roughness of
the road surface which in some creates cracks or more critical damages on the structural element
installations or finishing The solution is to use To minimise transportation difficulties the vehicle
having vibration absorber can be used to minimise damage due to vibration and additional
precautions need to be considered for wider modules while low bed transport vehicles are
preferable for transporting taller modules (W Ferdows 2019) Moreover loading and offloading
processes must be carefully done by precise strategy and adequate equipment in order to avoid
the harms on the products
bull Transportable materials There are two terms which force modular constructors to use advanced
and high-quality materials transportation and design situations Transportation as it mentioned
earlier puts limitations on the final product and force the constructors to use material which have
less weight more against resistance road vibrations and endurance against sunlight and humidity
exposures In one word these materials must be part of a final product which can be
transportable Often these materials add costs on the project because they are more expensive
than the ones which have been used in conventional buildings All properties need to be
structurally sound in situ but units built using offsite construction methods also need to be
structurally sound whilst being raised and lowered throughout the transportation and assembly
stages of the process Key structural elements such as beams columns and potentially walls and
floors must be repeated in three-dimensional modules for transportation purposes This can
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
45 | P a g e
significantly increase material costs depending on the material choice and level of design
optimization (McKinsey amp Company 2019)
On the other hand numerous benefits which modular construction has in terms of material
such as less reworks discount on massive offers no exposure to natural causes and its off-site storage
and less waste during the production can assure the constructors that these challenges can overcome
the fact that modular buildings work better than conventional ones in a material criteria
Wrong perceptions among public and real estate market
Innovation without correct publicity brings wrong perception among people and markets
Also errors bad experiences of users and unprofessional works can change the mindsets quickly by
unsatisfying the users and in result investors During a period in past off-site accommodations were
mostly for temporary uses with low quality material and less functional features The demands of
permanent housing raised after a break such as world wars for those who lost their houses and
refugees that wanted to live abroad Therefore numbers of companies started to modify their off-site
products in order to have more lifetime and serviceability However there were constructors who
could not provide buildings with better functional services and the users became unsatisfied and lost
their trust in these products This wrong perception had been raised even until now that off-site
building such as modular ones will not serve a long lifetime and have low quality material incommode
and unattractive design and a poor functionality Obliviously bad perception of people will reduce the
demands and destroys the market as well
Today the industry recognizes the need for durable construction for even temporary uses
making it possible to move and re-use full buildings So a lack of knowledge among consumers as to
what is possible can prevent design innovation In order to overcome the stigma sometimes associated
with modular construction manufacturers attempt to offer a built product indistinguishable from one
built onsite Therefore the industry advertises a direct alternative to onsite construction In a
comparative analysis of the two processes time savings and worker safety stand out as the primary
advantages of modular construction over onsite construction The building manufacturing process
itself construction in a controlled environment with access to advanced technology is an evolution
of the art of building which is traditionally slow to evolve The modular building industry therefore
should advertise a different building product altogether featuring design innovation and ingenuity
executed through advanced building techniques (Joseph M Schoenborn 2012)
Moreover in order to raise the demands among the public who can be future users a range
of positive publicity about the environmental advantages such as less emission economic savings like
less energy bills cheaper and easier maintenance processes during the operation phase and faster
construction process which help them to be accommodate sooner can create a positive mindset
among the public In addition post-sell services from constructors such as better assurance policies
for buyers maintenance services and offering loans to customers who are in emergency
accommodation needs can change the market significantly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
46 | P a g e
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects (casasinhauscom)
Integration of advanced software
As it mentioned before modular construction can benefit from using innovative software in
their designing phase in order to be more precise on planning and provide detail for the production
line One of these software programs is BIM which can be used in design construction phase on-site
assemble and even operation phase However despite its advantages there will be some challenges
as well The greatest challenge of using BIM in construction project is the implementation process
itself regardless of the software capabilities Development of accurate BIM model requires extensive
resources and in-depth knowledge of construction methods and process Most small or medium firm
could not afford the special team and man hours to aligning BIM (Na Lu and Thomas Korman 2010)
Other than finance and organizational issues the project team has experienced legal challenges as
well The use of BIM technology encourages multi-disciplinary collaboration which contrasts to
defining responsibility to each party and then assigning liability issues among the parties In addition
using BIM models instead of traditional contract documents raises questions on insurance coverage
and confidentiality exposure Ownership and control of the model use and distribution of the model
and intellectual property rights are some of the issues that need to be addressed while BIM
implementation being adopted in construction industry
Redefining the contracts
Due to the changes over the responsibilities of every participants the amount of their
influence on projectrsquos activities and transferring most of the work to the off-site plant a new way to
contracting is needed in order to optimize the relationship between the owner designers and
manufacturers during all phases of the project Here are some of the common types of contracts which
are being used among modular building industry
bull Design-build The architect modular manufacturer and onsite general contractor are
hired as a team and assume the responsibilities of design and construction together DB contract can
be named one of most traditional types of contracts that would create an integration between all the
parties of a project Due to the design-build nature of modular construction a close partnership is
demanding during the project phases
bull Design-bid-build After the architectrsquos design has been approved by the client a
competitive bidding process takes place This results in a greater disconnect between parties The
common gap between participate happen a lot in this type of contract which frequently can cause
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
47 | P a g e
misunderstandings about responsibilities of each expert incomplete information about the project
design or executive details and lack of transparency among the participants
bull Negotiated bid The modular manufacturer is hired first by the client to find the
appropriate architect and onsite general contractor that can be hired within the constraints of a
budget This concept may increase bonding between experts and improve everyonersquos understandings
about many aspects of the project But the budget will decide whether the quality level design
enhancement can meet the clientrsquos requirements or not In addition in case of clientrsquos approval the
question would be the future userrsquos satisfaction can be achieved or not due to the budget limitations
on the project quality level
bull Certified Modular Architect (CMA) A sustained relationship between an architect
and a manufacturer can be developed over multiple projects Therefore a certification process
providing training and continuing education can be introduced to the modular building industry An
architect intimately familiar with modular construction is best suited to handle coordination issues
that arise when work is being done in the factory and onsite simultaneously A it mentioned earlier
architects understanding and knowledges is critical to avoid possible mistakes and unsuitable designs
for modules Therefore this certified education which can be called as a semi-professional internship
for the design team in order to be present at every phase of the project
Supply chain-transportation-onsite assembly management errors
One of the main objectives to use prefabricated elements in construction is to raise the
productivity in execution phase which is mostly happens in off-site plant As it mentioned before there
is a supply chain in manufacturing plant and its productivity is depended to many key factors which
will happen outside of the factory Continuity of assembly operation is one of them which would be
happening in parallel with off-site supply chain After the modules were prepared to be transported
to the site the transportation system must be synchronized with the factory delivery and assembly
demands If any delays may happen during the transportation would affect the both origin and
destination scheduling storage policies and demands
On the other hand assembly line also must on-time and well-communicated with off-site
plant experts because any changes in execution phase can make huge negative impacts on supply
chain productivity Therefore these three important phases must plan based by on-site demands
supply chain productivity execution management and transportation systems
Figure 2 51 - synchronization between supply chain transportation and on-site assembly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
48 | P a g e
3 Common challenges in modular construction industry by a
survey Methodology
Objective
This study used qualitative research and specifically a grounded theory methodology to
uncover more information about advantages of modular construction and its constraints or barriers
to develop this method in the market Qualitative research emphasizes the influence of the researcher
on the data collected
Role of the researcher
In this study I acted as the sole researcher who was responsible to design questions based by
literature reviews and then by creating an online survey form try to collect the data from the
participants
Ethical considerations
To protect the rights and guarantee the safety of participantrsquos information following actions
were done
1) The research objective and process were made clear to the participants
2) The collected data was used for research objectives only
3) Only eligible participants who are modular constructors and manufacturers were
chosen for this survey
4) The access option to the survey information gave to the participants after the
research was finished
5) The anonymity of the participants was maintained
6) The name of the participant and their brand was remained confidential for all roles
even the researcher to obey the law of data protection
Survey setting
Due to the emergency restrictions which caused by a virus pandemic across the world several
options were unavailable to be done such as face to face interviews factory visits and project site
practices Therefore online interview was the only solution which can be happen without any danger
for participants and researcher In most regions construction companies are suffering from a full shut
down on their production line and on-site projects so that access to these participants became even
harder than usual Thus an online survey form by office forms was chosen for this research so that
the participants can answer the form questions at any time and location with ease to answer by
multiple accesses to the formrsquos link (Figure 31)
This survey forms had been sent by email to the official addresses that were mentioned in
their websites for contact The priority in choosing the recipients were the construction managers
project managers and executive engineers so that the information will be collected from the operation
managers who have the most technical experience and have the most knowledge with construction
phases from off-site production to on-site installation This could also help the survey to find the
challenges during the construction that were not able to be visited due to the restrictions of global
pandemic
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
49 | P a g e
Figure 3 1 - Online office forms for survey use
The estimated time was reduced to 13min with the most important questions to improve the
efficiency and be timely reasonable for the participants
Development of questionnaire
After hours of study on numbers of articles which have focused on challenges in modular
construction industry several were found that have lack of scientific scope and recommended
solutions Therefore many of the questions were designed to first shed a light on the potential
advantages which have not been mentioned specific and completely unknown for the industry For
instance the social benefits which came immensely useful during the COVID-19 pandemic for health
centres and medical infrastructure etc Moreover a lack of inconsistency between industry and
science came to notice which shown a massive gap between these two important roles in construction
industry This gap explains that the scientific researchers in some areas have the minimum contact
with industrial players in construction world in comparison with other industries which the opposite
situation is applied To fill this gap questions were designed in a way which have an origin of scientific
researches and direct and first-hand information from the construction industry players which are
constructors modules manufacturers etc
Development path of questions can be explained as critical path to the best details of each
criteria than can obtain useful information from participants In terms of advantages the benefits
which were identified from literatures were ordered and asked form participants to be confirmed and
validated by the industry players in real project cases For instance in an environmental point of view
Reduction in Energy Consumption was identified in literatures and had been asked among participants
to confirm the hypothesis that modular construction can reduce the energy consumption in
comparison with traditional methods (Figure 32)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
50 | P a g e
Figure 3 2 - Questionnaire development
Participant profile
Experience amp professions
As the ldquoTable 31rdquo explains information from five companies have been selected for this
survey with variety of backgrounds from pioneers to well-experienced players in industry with over
than 120 years of experience in the modular construction society as constructors and modular
manufacturers The experts who answered have different roles in the industry from CEO to architect
and sales managers so that the data can have more perspectives of views on the questions such as
sales market and design process to project management Table 3 1 - Participantrsquos profiles
Because of diversity in the influence of challenges between massive international builders and
local players these five companies responds have been compared to each other from company C
which is a local constructor to company E that is currently executing modular projects in 80 countries
with approximately 6000 modules build annually
Types of materials in some cases can have different statistics in results For instance in
modular construction which steel and wood modules are more often used in projects can produce
various amount of CO2 emissions and waste or recycle process can be done with more ease For that
reason these survey all types of materials are considered including steel modules concrete modules
and wood modules There is also an argue that some benefits and challenges cannot be seen in unique
projects with more repetition in production of elements and mass production such as hotels and
schools while in residential projects can exists more than the others To cover all the contrasts of
60 of participants
can acheive a 30-40
reduction energy
consumption
A Our homes are not positive from an energy
perspective
B We can finish a 4 months traditional project in 8-10 weeks and Energy consumption of a factory is known and relatively constant on a weekly
E 30 reduction in energy consumption
Modular construction can
reduce the energy consumption up
to 30 in compariosn with
conventional methods
QsCompany A B C D E
Years of company experience 10-15 10-15 20-30 20-30 30-50
Position of participant CEO Sales Manager Design Architect Quantity Surveyor Foreign Trade Manager
Professional experience 15 13 30 NA 3
No of employeesfactoryModules build annually 801200 1301490 151- 50280 25026000
Type of material(WoodSteelConcrete) W amp S W W W S amp Conter amp fiber cabins
Types of Projects (ResedentialSchoolsHospitalCommercial) R R amp S amp C R R amp S amp C amp H R amp S amp C amp H
Use of BIM Yes No No No No
Level of automation 20 reaching up to 80 20 Off-site 60 On-site 20 20 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
51 | P a g e
information these companies have been selected that are involved in all types of modular building
projects including residential hospitals schools and commercials buildings
As it mentioned before BIM program can advance the projects in many ways however
unfortunately among these participants only company A is able to benefit from this software from 0
to 100 of the project Therefore the further arranged interview focused on BIM Function was
cancelled and may be done in the future investigations
Automation can play an important role in improving the productivity and sustainability of
construction processes as a part of ldquoindustrialization in constructionrdquo movement Among survey
participants the minimum automation level in off-site plants is 20 and maximum of 60 and in on-site
activities can be up to 40 In addition company A claimed that in near future their automation can
reach up to 80 which is an innovative move in construction industry On the other hand company
with over than 6000 modules build annually have a significant 60 of automation in their plant which
shown a massive interest of investment on this technology In addition automation application
difficulty have direct relation with the type of materials used in modules and type of the projects which
as Table 31 illustrates company E with the most variety in project types and materials use have
achieved a huge success in application of automation with a level of 60 which also helped a lot to
expand their market overseas
Data collection
General information
All the received information has been attached in ldquoAnnex 1rdquo where the responds are not
edited and mentioned in the original shape Here are the shorter versions of responds
bull Motivations to choose modular construction over traditional
To bring the attention of investors to an innovative method reasonable motivations are
needed which can be the current demands of market economic profits and environmental benefits
Therefore it was necessary to identify the motivations of these companies to start a modular
construction form Economic advantage for most of these has a priority not just for being profitable
but for being able to develop their dominance in the future On the other hand innovation has an
approximately same amount of interest which explain the reason behind choosing modular method
that is one of the most innovative off-site construction methods in the industry
The fact that mentioned before in literature reviews high demands in the market and the lack
of provide by construction players is one of most important reasons to apply a fast and high-quality
solution for reach the satisfaction of housing market Shorter schedule and environmental benefits
took the next places of priority in motivations for these companies which are also important for sure
Figure 3 3 - Participants motivations to start a modular company
28
9
18
18
27
Economic benefits
Enviromental benefits
Shorter schedule due to the need
High demands of housing in themarket and lack of provide
Innovation
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52 | P a g e
bull Built in factory panelssubcontracted panels used in modules
All five companies are manufacturing the panels that used in modules by their own inside the
off-site plant which as it mentioned earlier the selected participants have a variety of production rates
and by this information that they are able build their own panels it can be said that their production
is 100 off-site However in the case of company E which is a massive international modular player
there are some types of modules that are being provided from domestic market because of economic
feasibility issues
Economic issues
bull No of labourLess wages of salaryAdded value in each hour of workneed of
special workforce
Generally the participants mentioned that there fewer number of workers are needed on and
off site in comparison with traditional method About the amount of salary wages company A
confirms that for each hour of work off-site less amount wages are being paid to workers On the other
hand the shorter schedule of projects in modular projects can reduce the payments as well The fact
that most of the participants are emphasizing is that the efficiency of work and added value of
activities off-site are much more than the on-site traditional projects where company A acclaimed
that in terms of efficiency ldquo1 hour in the factory is equal to 4 hours on-siterdquo
Environmental status
bull Life cycle duration of products and material recycle
Company B acclaimed that they do have multiple solutions for each materials that theyrsquore
using in their modules for instance the unusable drywalls and PVC materials which they send for
recycling or the woods that would use into mulch products or for heating by others
Company E told that their products have a 50 years life span which is the same as a lifetime of
traditional build residential house However company C have some difficulties in recycle and reuse of
their elements because of unportable feature of their products
bull Integration the modules with other innovative technologies
Four of these five companies confirmed that their products have the option to integrate with
other innovative technologies such as self-powered homes by solar panels and also using advanced
insulation technics made by non-petroleum materials in their panels to reduce the energy
consumption during operation phase
bull Waste reduction
Company A acclaimed that their production line generates significant amount of 70 less
waste in comparison with traditional method The rest of the companies focused on carbon footprint
reduction and were able to reduce it 15 less that traditional method by choosing environmentally
friendly technologies in production and wise choice of materials for their products
bull Reuse of structural and non-structural elements in projects
Three of five participants confirmed that they have the ability to re-use their products in the
next projects in order to reduce the waste and energy consumption during the manufacturing
processes Type of the projects and material have the direct relation with the potential of reusability
in elements and due to the variety that the participant have in both criterions the potential is variable
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
53 | P a g e
Figure 3 4 - Re-use potential
bull Reduction in Energy Consumption
Company E mentions that modular construction can achieve a 30 of energy saving in
comparison with traditional site-build method while company A acclaimed that their homes are not
positive from an energy perspective Company B gave more details on energy consumption by making
a comparison between off-site activities and on-site traditional construction and acclaimed that due
to the shorter schedules in off-site production energy consumptions can be reduced up to 50 They
mentioned that ldquoEnergy consumption of a factory is known and relatively constant on a weekly
monthly and annual basis A competent and experienced modular builder can many times finish the
entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-
built house could require as much as 4 months for the same completionrdquo
Social Benefits
bull Delivery of projects for emergency services during COVID-19 Period
As it mentioned earlier due to the virus pandemic that is happening at moment in all around
the world a rapid response is needed more than ever for emergency services for health organizations
and according to this survey one of these companies is providing products for this cause which can be
a good news and accounted as a social benefits for this method of construction
Figure 3 5 - Contribution in Covid19 epidemic
bull Providing post-sale services for clients
In contrast with conventional construction which just have the responsibility until the delivery
of the project modular constructors because of their industrial profile have the ability to offer post-
No40
Yes60
Reuse the structuralnon-structural elements projects
No
Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
54 | P a g e
sale services to the clients such maintenances upgrades etc due to the results of this survey four of
these five companies confirmed the availability of post-sale services for their clients
Figure 3 6 - Post sale services por future clients
Initial costs
bull Initial investment and its Payback period
Company A claims that their initial investment to establish their company was about 20 million
Canadian dollar and its payback period was 5 years Company E had the amount of 15 million USD with
the same 5 years period However company C like many of the older players in modular construction
industry who started way earlier cannot estimate their initial investment
bull Factors that can change the initial costs
There are factors which can make a change in initial costs of companies The participants
prioritized these 6 chosen factors starting with product types and production range with 31 of
importance among others Level of automation took 25 share of the pie chart which has direct
relation with the initial costs Off-site plantrsquos location has 19 of efficiency on starting costs and
furthermore the quantity of sub-contracted players in the projects achieved 13 of the graph Finally
financing and design enhancement have the minimum equal shares of 6 which despite of being the
last factors have the efficiency on initial costs as well
Figure 3 7 - effective factors in initial investments for start-up companies
6
25
31
13
19
6
Factors that effect on initial costs
Design enhancment Level of automation
Product types and production range Less sub-contracted
site location Financing
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
55 | P a g e
Design limitations
bull Design boundaries caused by production line
Company A mentioned the subassemblies as the main element to be considered in design
phase while company D and company B introduce a maximum dimension for their production lines to
be economically viable for transportation costs In addition to those company C and company E
confirmed that there are no boundaries for the designer caused by the production lines because of
their wise choice of prefabrication methods
bull Lack of knowledge from architectsdesign engineers about production processes
transportation limitations etc
One of the main problems of start-up companies and the experts who join the modular
construction industry is the lack of knowledge about off-site processes and transportation limits
Three of five participants confirmed that there is lack of knowledge in these area from designers
Figure 3 8 - Lack of knowledge among designers and engineers
Transportation Limitations
bull Transportation regulation effects on modular projects
Three of five participants confirmed that the regulation by transport administrative can be
harmful for the projects such as extra costs or time delays on schedule Company A mentioned the
time delays in giving permits to the manufacturers and constructors which can damage the
synchronization between production line and on-site installation by reducing the speed of
transportation of elements to the site Company B added information about transportation system of
some states in America which use the term ldquoSuper Loadsrdquo to put limits on oversized shipping that
increases the cost and time on the project On the other side Company C as a strategy to avoid this
problem used legal load limits in their design instructions so that their products will obey the
regulations
bull Transportation boundaries on material choice and project costs
Company B D and E confirmed that the terms of special transportable material will not add
extra costs on the project Company A acclaimed that the extra costs by transportation can be offset
by speed of production and reduced financing costs for the project
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
56 | P a g e
Project management challenges
bull Difficulties in using automation in off-site production
In this survey based on literature reviews 4 main reasons for difficulties of using automation
in off-site production were selected to ask the participants Integration with advanced software and
high expenses of application in production line took approximately 60 of importance among others
Codding problem is another major problem in this subject which have 28 of pie chart In addition
company A demanded ldquoAn international coddingrdquo as a solution for this problem The last section
belongs to ldquolower salaries of manual processesrdquo which has the minimum importance of 14 among
participants
Figure 3 9 - challenges of using automation in off-site plants
bull Contracting problems
Starting with company A which acclaims that every state has its own code and the lack of a
universal code can bring challenges for modular players
Company B explained about the misunderstanding by final client who is the end home buyer
who ldquobelieves the factory to be the builder and the actual independent builder to be a sales agent
for the factoryrdquo Their recommended solution for this problem is to define the relationship between
the participants of projects their responsibilities by social media and requiring the builders customer
to sign a disclosure acknowledgement from that describes the relationship in detail
Company C mentioned a financial challenge caused by the banks in the projects that are
financed by them (Banks) which do not consider the project done until erected on-site This issue
creates pressure on cash flow of project where bank finance is involved The only problem that
company E consider in terms of contracts is lack of timing on project delivery which is generally causes
by constructors or general contractors
bull Lack of synchronization between projectrsquos participants
To begin with company A believes that there is a lack of quality partners on site They explain
that the problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution Company B mentioned that the responsibility of ensuring
28
29
29
14
Difficulties in using automation in off-site production
Codding Integration with advanced software Cost Lower salaries of manual processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
57 | P a g e
that the work is done properly belongs to the builder which any ldquodelays in this can result in postponed
transport of product and interest through demurrage charges
bull Sub-contractor for site planning and foundation phase
Company A uses local subcontractors for their site planning and foundation phases because
of variety of locations of their projects and ease of using local subcontractors Company B have only
the responsibility of modules production and defines the customer (the general
contractorindependent builder) responsibility to execute rest of the project phases have sub-
contractors if needed Company C does have sub-contractors for site-preparations and foundation
phases under direct supervision and the reason to not performing by their own is the high costs of
required equipment and not being portable for each project
bull Technology gap between sub-contractor and modular constructor
The only issue that were mentioned by participant is where company A recommended to ldquoto
educate most local subs on our process and reason for doing things a certain wayrdquo
Company B and C acclaimed that there are no challenges for the off-site production
Social challenges
bull Wrong perceptions among public and market
The only value that the market considers choosing modular method over traditional
construction is to be cheaper Company A says
According to company B experience in USA majority of people the media and even
professional engineers do not understand the capabilities of modular construction Many people
continue to confuse this form of construction with HUD on frame products
Another wrong perception that the publicmarket believes is that the prefabrication methods
limits the design options while Company C believe confirms that the reverse is the case
bull Solutions for resolving the wrong perceptions
Company A believes by using one of the main advantages of modular construction which is
shorter schedule the market can be dominated by modular projects and the more cases they deliver
the more recognised this method would be among the public and at the end the superior nature of
modular approach can be proved Company B addresses a solution in a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Company C acclaimed that advertising the modular advantages
among the public would be enough
Data analysis amp conclusions
The data from this survey can be used as an input data and prioritizations for the next chapter
which is decision-making process between four alternatives The solutions and recommendation will
be repeated at the recommendations at the final chapter as well Here are the conclusions about
advantages and challenges in modular construction mentioned by professional participants
Advantages
Economic benefits Generally apart from the other benefits as the participants mentioned
that there fewer number of workers are needed on and off site in comparison with traditional method
and Due to the shorter schedule of projects in modular projects can reduce the payments wages
Other fact that most of the participants are emphasizing is that the efficiency of work and added value
of activities off-site are much more than the on-site traditional projects
Environmental benefits Due to the variety of solutions for each material that they are using
in their modules there is high potential to send the used elements for recycling or would use into
mulch products A long lifetime span is acclaimed for the products which is close to the traditional
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
58 | P a g e
ones Majority of participants confirmed the literature concept that their products have the option to
integrate with other innovative technologies such as self-powered homes by solar panels and also
using advanced insulation technics made by non-petroleum materials in their panels to reduce the
energy consumption during operation phase In the waste management term there is a possibility for
production lines to generate significant amount of 70 less waste in comparison with traditional
method Moreover about carbon footprint reduction there is ability to reduce it 15 less that
traditional method by choosing environmentally friendly technologies in production and wise choice
of materials for products While there is argue that modular construction can achieve a 30 of energy
saving in comparison with traditional site-build method there are claims that their homes are not
positive from an energy perspective However this idea mentioned that by making a comparison
between off-site activities and on-site traditional construction due to the shorter schedules in off-site
production energy consumptions can be reduced up to 50
Social benefits As it was mentioned in literature reviews there are social benefits in modular
construction that can improve the satisfaction of clients Post-sale services for customers are possible
which is completely opposite to the traditional projectrsquos conditions
Challenges discussion
Initial costs It is obvious that a high amount of investment is needed to stablish an off-site
plant to start prefabrication of construction elements but the payback period is not that long that put
boundaries for start-up future players due to the collected information There are factors which can
make a change in initial costs of companies that are prioritized by the participants starting with
product types and production range level of automation which has direct relation with the initial
costs Off-site plantrsquos location the quantity of sub-contracted players in the projects and finally
financing and design enhancement have the minimum equal shares
Financial aids Financial assists which are crucial for kind of projects that are dependent to
these aids are not harmonized with modular project processes where there are argues that until the
first deliveries of elements to the site location and their assembly these aids are not reachable This
issue creates pressure on cash flow of project where bank finance is involved Changes in contract
conditions and education for financial supporters are recommended solutions to improve the
partnerships in projects
Design boundaries it was mentioned the subassemblies as the main element to be
considered in design phase while some players introduce a maximum dimension for their production
lines to be economically viable for transportation costs However there a possibility to eliminate the
boundaries for the designer by the production lines because by wise choice of prefabrication product
types
Lack of education The idea of lack of education among engineers and architects about off-
site construction methods was proved by the collected information which have to be resolved by
updating the education resources to innovative methods that can improve the productivity rates and
sustainability
Transportation regulations negative effects it is confirmed that the regulation by transport
administrative can be harmful for the projects such as extra costs or time delays on schedule Time
delays in giving permits to the manufacturers and constructors which can damage the synchronization
between production line and on-site installation by reducing the speed of transportation of elements
to the site A strategy to avoid this problem used legal load limits in their design instructions so that
their products will obey the regulations
Choice of transportable material effect In contrast with literature review which mentioned
the idea of extra costs by choices of transportable material this survey confirmed that the term of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
59 | P a g e
special transportable material will not add extra costs on the project Moreover the extra costs by
transportation can be offset by speed of production and reduced financing costs for the project
Automation use challenges Integration with advanced software and high expenses of
application in production line took approximately 60 of importance among others Codding problem
is another major problem in this subject In addition ldquoAn international coddingrdquo was mentioned as a
solution for this problem Every state has its own code and the lack of a universal code can bring
challenges for modular players ldquolower salaries of manual processesrdquo has the minimum importance
Defining responsibilities boundaries There is a misunderstanding by final client who is the
end home buyer who ldquobelieves the factory to be the builder and the actual independent builder to
be a sales agent for the factoryrdquo Their recommended solution for this problem is to define the
relationship between the participants of projects their responsibilities and requiring the builders
customer to sign a disclosure acknowledgement from that describes the relationship in detail
Lack of partnership among projectrsquos participants There is a lack of quality partners on site
The problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution The professionals answered that the responsibility of
ensuring that the work is done properly belongs to the builder which any ldquodelays in this can result in
postponed transport of product and interest through demurrage chargesrdquo
Wrong perception of publicmarket The only value that the market considers choosing
modular method over traditional construction is to be cheaper while majority of people the media
and even professional engineers do not understand the capabilities of modular construction Many
people continue to confuse this form of construction with HUD on frame products Another wrong
perception that the publicmarket believes is that the prefabrication methods limits the design
options while some players believe that the reverse is the case Therefore by using one of the main
advantages of modular construction which is shorter schedule the market can be dominated by
modular projects and the more cases they deliver the more recognised this method would be among
the public and at the end the superior nature of modular approach can be proved Another solution is
a form of cooperation between builders manufacturers architects and engineers to educate the
public by national entities such as Modular Home Builders Association
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
60 | P a g e
4 Decision making based on potential advantages among three
modular alternatives and conventional construction method in a
project by MIVES software Methodology
Objective
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria potential benefits can be recognised However to find out how much practical these benefits
are in the market several trade-offs must be done by professional tools such as project management
software programs which can take decisions based on the input data that receive
The objective of these thesis is to examine the practicality of modular construction by taking
the best decision among 4 alternatives including a conventional armed concrete building with steel
modular concrete modular and timber modular methods and see that the mentioned advantages can
lead the methods to become the best option to choose for building the project as a project
management point of view
What is MIVES
In order to make the most sustainable and reasonable decision among the alternatives a multi-
criteria decision-making program was used called ldquoMIVESrdquo MIVES is the acronym for Modelo
Integrado de Valor para una Evaluacioacuten Sostenible which means Integrated Value Model for a
Sustainable Assessment It is a multi-criteria methodology for decision making It allows transferring
the different characteristics of the objects to be evaluated to a series of homogeneous and
quantifiable parameters which facilitate the objectification of the choice
The MIVES methodology consists of creating a model that defines all the characteristic
features of the elements to be evaluated assigning them a function that allows converting the
different peculiarities of the alternatives into a common unit which we will call value Once the
amount of value for each alternative is obtained it can be used for a sustainable evaluation
(wwwdecaupcedu)
Data collection process
Case Study references
bull Journal of Cleaner Production (WAHammad 2019)
(httpsdoiorg101016jjclepro201904150)
This Fabolous multi-criteria comparison was done between two methods of conventional and
steel modular building in two cases case A which is a normal residential building and case B a school
building to measure the sustainability level of them in economic environmental and social areas The
location of this was considered in Sydney and central coast Australia and four BIM models had been
designed for each alternative in both cases The total floor area of Case A is 63 m2 (87m x 72m)
When adopting modular construction the granny flat is designed from 2 modules each module is
36m x 87m Case A was chosen as the study case to focus on because of type of the project that is
residential building
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
61 | P a g e
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study (WAHammad 2019)
The purpose of this journal is to add sustainability criteria as main factors for constructors to
make a multi-dimension decision whether to use Modular construction for a project or continue with
conventional methods
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and conventional methods
(Akbarnezhad 2019)
bull A comparative life cycle assessment (LCA) of concrete and steel-prefabricated
prefinished volumetric construction structures in Malaysia (Ali Tighnavard
Balasbaneh 2020)
(httpsdoiorg101007s11356-020-10141-3)
This researchrsquos focus is to compare two types of volumetric modules function in terms of cost
and LCA factors such as Greenhouse emission etc on a residential project with the approximate area
of 105m2 located in Malaysia based on local regulations Prefabricated Concrete Modules (PCM) and
Prefabricated Steel Modules (PSM) were considered for this project Recently Malaysian
administrative system has been pushing the companies and researchers to investigate on these types
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
62 | P a g e
of construction methods in order to measure the benefits and obstacles of using them in future project
and try to resolve the productivity problem in construction industry The construction industry in
Malaysia has been labelled ldquounproductiverdquo for its reliance on a large labour force and its use of non-
prefabricated strategies at a proper scale (Balasbaneh 2020)
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020)
bull Modular vs Conventional Construction A Multi-Criteria Framework Approach
published at ISARC 2017 (AWA Hammada and A Akbarnezhad 2017)
This paper did a comparative analysis in cost time and carbon emissions by BIM models
Material and equipment libraries and existent databases on a project in the North-West of Sydney
involves the construction of a granny flat with dimensions 14 m by 16 m
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017)
The framework of this papers based on the BIM model analysis with input data project actual
projectrsquos budget material and equipment used in the construction and environmental information in
database and then a comparative study on emissions during constructionmanufacturing schedule
and costs of project for crew material and equipment (Figure 45)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
63 | P a g e
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad 2017)
bull Life cycle greenhouse gas emissions and energy analysis of prefabricated reusable
building modules published on Energy and Building (Lu Aye 2011)
(httpsdoiorg101016jenbuild201111049)
Aye and his team did a LCA study on three alternatives PSM PCM and PTM which were used
in a multi-residential building with 63 apartment units with area of 63 m2
Figure 4 6 - Architectural section of multi-residential building (Aye 2011)
The modules in this study were categorized in 4 main elements Exterior walls with insulation
panels Interior walls used for internal separation which mostly build with timber frames and plaster
boards Floors with plywood material on topping in all alternatives and ceilings with thick plaster
boards and steel concrete and timber parts as main elements (Figure 47)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
64 | P a g e
Figure 4 7 - Structural elements used in modules (Aye 2011)
bull Comparing Environmental Impacts of Building Modular and Conventional Homes in
the United States published at Construction Matters (John Quale 2012)
(httpsdoiorg101111j1530-9290201100424x)
Quale did also a comparative analysis focused on Environmental emissions on two PTM and
Conventional Timber building Three residential modular companies generally representative of the
eastern US modular industry supplied data on completed projects for this study including utility
bills worker commuting information building materials and waste procedures construction
schedules employee schedules and other relevant information (Quale 2012) 186 m2 two-story
home that is a model for one of the companies involved in the study
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
65 | P a g e
Input data
4221 Alternatives
Four alternatives were selected for these study which are one conventional armed concrete
(Reinforced concrete RC) structure prefabricated steel modules (PSM) prefabricated concrete
modules (PCM) and prefabricated timber modules(PTM) that are most common solutions used by
contractors in the construction industry
4222 Requirement tree
These are groups of criteria which define a function to be evaluated A requirement usually
has several criteria Five requirements were selected based by literature review and the expertrsquos
opinions collected by survey among industrial players who were the participants of this questionnaire
Economic R1 time R2 environmental R3 safety R4 and social R5 requirements arranged in a way that
can examine the advantages adequately Time requirement were separated from economic one
because of importance due to high priority that have in the market to be chosen by the constructors
and clients In other words some clients and private builders choose the prefabrication methods such
as modular construction to save more time due to tight schedule that the project have Social and
safety requirements usually not being considered in sustainable decision-making processes but on this
study were included because the sustainability is not the only factor in project management
4223 Criteria
For each requirement a series of criteria are defined Criteria are the specific concepts that
the indicators contain the minimum unit to be quantified (wwwdecaupcedu) Each criterion was
chosen based on the importance among others efficiency on the project and availability of actual
amount and quantities in real cases over literature resources In other words the both advantages
and their functionality that modular construction have in comparison with traditional methods were
the main drivers to choose a criterion for each requirement as it mentioned earlier For economic
requirement cost of the project R1C1 was the only criteria that was considered which in the literatures
is expected to save 20 by choosing modular method in final cost (McKinsey amp Company 2019) while
experts in survey believe that the cost of transportation of prefabricated elements to the site can
compensate the difference with traditional method To examine these two opinions these criteria was
chosen In Time section the projectrsquos schedule R2C1 was only criteria to measure the important
advantage that the modular construction has Both literatures and expert agreed the time saving that
modular approach can bring to the project which is about 50
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES)
R1 - Economic
R1C1 - Project cost
R2 - Time
R2C1 - Project schedule
R3 - Environmental
R3C1 - Energy consumption
R3C2 - Waste generation
R3C3 - Material consumption
R3C4 - Noise Polution
R3C5 - Greenhouse gas emission
R3C6 - Recycle
R3C7 - Embodied energy
R4 - Saftey
R4C1 - Injury risks
R4C2 - Protection from natural cuases
R5 - Social
R5C1 - Job status
R5C2 - Quality
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
66 | P a g e
Seven criteria were chosen to cover the environmental requirements for this decision-making
process based on the available data in literatures However in this section not only advantages of
modular methods were considered but in some areas conventional reinforced concrete showed
better results and this fact can improve the liability and practicality of final decision For instance the
embodied energy of steel modular building is 30 more than the conventional during the construction
but the saving caused by re-useability of element in modular method can almost compensate the gap
between these two methods Energy consumption R3C1 which is the energy consumed during the
constructionfabrication amount of Waste generated R3C2 in all alternatives Material consumption
R3C3 in each method Noise pollution R3C4 Greenhouse gas emission R3C5 Recycle of elements R3C6
and Embodied energy for each method were chosen in this section
Safety issue as it has mentioned before was added to decide further than sustainability
concept boundaries which include two criteria Injury risk for workers R4C1 and Protection of project
from nature causes R4C2
Finally Social benefits which are not as main factors to be considered by construction players
to use the modular methods but are important enough to pay attention and were compared as well
by two criteria Job status R5C1 and Quality R5C2
4224 Indicators
The indicators for this study came directly from scientific articles which most of them were
published few months ago and it can be said that the data which were used for this study is updated
with the latest achievements in modular construction industry
To begin with for economic measurements two indicators for the project cost were selected
total project cost R1C1I1 and costs stability R1C1R2 Total project cost R1C1I1 for conventional RC
alternative means the final cost of construction including all the activities until the delivery of building
In modular alternatives PSM PCM and PTM includes the module fabrication in off-site plants
transportation installation on-site and final finishing of building after the assembly phase All
indicators are based on ldquoAustralian dollarsrdquo units (AUSD) because of the recourse quantities that was
used for this study which will be discussed more later Second indicator which is the costs stability
(R1C1R2) was chosen because of the common off-site production economic advantage that is
stabilizing the costs for the projectrsquos budget because of high quality of product more repetition of
elements and more accurate supervision on activities which leads to less reworks and less extra costs
etc
Total project schedule R2C1I1 is the first indicator for time requirement which include the
amount of time to fabricate transport and final assembly of the modules on-site in modular
alternatives and the final schedule of the conventional project during construction activities until the
delivery of the building which all are based on ldquodaysrdquo it was mentioned earlier that in off-site
production the project schedule can be estimated and controlled more adequately so that second
indicator which is time stability R2C1I2 was introduced to the study
Environmental requirement was studied in various features as it said before in 7 criteria which
shows the complexity of comparisons between alternatives First indicator is the Energy utilized during
construction R3C1I1 based on ldquoMJrdquo units Solid Waste R3C2I1 is the only indicator for Waste
generation criteria that focuses on the amount () of waste which was produced during
constructionfabrication activities in all four activities In material consumption criteria the total
amount of materials that was used for constructionfabrication of elements R3C3I1 is appointed as an
indicator to compare the benefits in each alternative based on ldquoKgrdquo Noise reduction in off-site
construction is another benefit that it has and to discuss this fact among the alternatives Average A-
weighted equivalent sound level of each construction equipment R3C4I1 based on ldquodBrdquo units was
focused on Greenhouse gas emission among alternatives was measured in CO2 that was produced
during constructionfabrication activities R3C5I1 based on ldquoKGrdquo units Two indicators were introduced
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
67 | P a g e
for recycle criteria between four alternatives recyclability or possibility of recycling of elements
R3C6I1 and Re-use of elements (Products) in projects R3C6I2 based on Percentages Embodied energy
was the last criteria which was focused on with two indicators Embodied energy used R3C7I1 in ldquoGjrdquo
units and Embodied energy saved by re-use of elements in percentages among alternatives
For safety measurements two indicators were selected for two criteria which are injury risk
level R4C1I1 for injury risk criteria and Protection level R4C2I1 for protection from nature causes both
in a qualitative unit
Job stability R5C1I1 for comparing the job status in terms of security of jobs among two
methods and new job creation R5C1I2 to analyse the possibility of providing new job positions which
is crucial in these era in construction industry were chosen in qualitative unit
The last criteria in social requirement which is quality of projects was presented with one
indicator of quality satisfaction of client R5C2I1 in qualitative unit to compare the clientrsquos satisfaction
level between alternatives Table 4 1 - Requirement tree with all indicators which considered for decision making process
Requirements Criteria Indicators
(R1) Economic (R1C1) Project Cost (R1C1I1) Total Project Cost
(R1C1I2) Cost Stability
(R2) Time (R2C1) Project schedule (R2C1I1) Total Project Schedule
(R2C1I2) Time Stability
(R3) Environmental
(R3C1) Energy Consumption (R3C1I1) Energy Utilized during construction
(R3C2) Waste Generation (R3C2I1) Solid Waste
(R3C3) Material Consumption (R3C3I1) Material Consumed in project
(R3C4) Noise Pollution (R3C4I1) Average A-weighted Equivalent sound Level of each instrument
(R3C5) Greenhouse Gas Emission (R3C5I1) Co2 in constructionfabrication
(R3C6) Recycle (R3C6I1) Recyclability of Elements
(R3C6I2) Re-use of elements
(R3C7) Embodied Energy (R3C7I1) Embodied Energy Used
(R3C7I2) Embodied Energy Saved
(R4) Safety (R4C1) Injury Risks (R4C1I1) Injury Risk Level
(R4C2) Protection from Nature Causes (R4C2I1) Protection Level
(R5) Social (R5C1) Job Status
(R5C1I1) Job Stability
(R5C1I2) New Job Creation
(R5C2) Quality (R5C2I1) Quality Satisfaction of Client
The input data for indicators are categorized in 4 types direct data calculated data estimated
data and qualitative data The reason for not having only direct data is the lack of enough literature
researches on this subject and in some cases the data were published two months before the date of
this study The variety of alternatives which is the first time that a study is going to analyse 3 modular
alternatives and a traditional method added difficulty to find useful data to do the decision making
reliable Moreover 5 articles were used for finding the correct data which each of them focused on
different alternatives The orientation of this study is the Cleaner Production journal by professor
Hammad that was published in 2019 which was mentioned earlier The reason of this orientation is
that most of the data came from this article and is more updated than the others
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
68 | P a g e
bull Direct Data
The direct data were the information that was related precisely to the alternatives without
any needs to change For instance the cost of the construction in Hammadrsquos article which can be used
without any changes The green parts on the Table 42 shows the direct data which are related to the
Hammadrsquos article Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed to be done on them
bull Calculated Data
In many indicators because of lack of existence in directly related data for alternatives a sort
of calculations were needed to change the data from other articles that related to alternatives that
are not focused in main case (Hammadrsquos article) to actual data based on the area of main article by
using accurate coefficients and ratios For instance in Hammadrsquos article CO2 was not estimated for
Prefabricated Steel Modules (PSM) alternative but Ayersquos CO2 data which is for total area of 3943m2
with 63 apartments each area of 628 m2 (close to 625 m2 area of Hammadrsquos granny flat) was used
by dividing on 63 apartments units so that results 54079 kg of CO2 for steel modular equivalent for
main case The yellow parts show the calculated data for indicators
3407000119896119892 1198881199002 divide 63 119906119899119894119905119904 (6251198982) = 54079119896119892 1198881199002 for steel modules in main case
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other studied
bull Estimated Data
Third type of input data were the necessary data which are not existed on any of literatures
of have to be estimated based on the qualitative information professional survey which have been
done before the decision making process (Chapter 3) and researcherrsquos opinions Fortunately in many
areas the data could be applied on other alternatives because of similarity of activities off-site and
onsite For instance for PCM alternative the noise and Injury risk level are approximately the same
the indicators of PSM case that have mentioned in Hammadrsquos article which are shown in green parts
in Table 42 because of similarity of off and on site activities during construction
The blue parts are the estimated data that were considered for PCM alternative based on
mentioned resources For instance the time indicator can be predicted 24 days few days more the
steel modules which is around 22 days because of the fact that concrete modules are heavier than
steel ones and has more complexity in structure for being produced that adds difficulties on
transportation process which leads to more delays on the schedule Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow)
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
69 | P a g e
bull Qualitative Data
This data was added because of two reasons first the lack of existence of direct data on
literatures and improve the literatures background on this subject and secondly to have more
influence from variety of benefits that modular construction has on the decision making process
Numbers of literatures insisted on advantages that can affect the decision making but did not
included on their data analyses at the end and this research decided to include these data and see
that how much functional can be in the decision making between alternatives in point of project
management view For instance cost stability which is better coordinated in off-site construction and
can be considered as an advantage to the decision making is not included in the literatures during
analysis and in this study is a vital factor for the economic criteria In order to add this indicator a
qualitative range was considered from 0 to 10 and four alternatives based on their functionality in cost
stability in project budget were compared to each other Traditional reinforced concrete building
which because of common reworks etc have less stability in final budget estimation On the other
side PSM and PTM which have the most repetition in manufacturing processes and ease of production
because of material type have the maximum cost stability of 9 out 10 among the others and PCM that
has less ease in production have less cost stability than other modular alternatives with 8 out of 10 Table 4 5 - Qualitative indicators
Final indicators
bull Prefabricated Steel Modules indicators (PSM)
As it mentioned before the direct data which are shown in green at table 46 do not need any
changes as they belong to the main case study while other indicators are still needed to be calculated
estimated and often considered qualitatively Aye case study have the closest data to the main case
study because of similarity of project type and dimensions so that the necessary indicators such as
material consumption waste generation percentage re-use amount and embodied energy indicators
can be calculated from this analytical study (For more information about indicators resources please
see Annex 1-A) Table 4 6 - First hand data over literature
A simple calculation is needed and that is dividing the CO2 emission Material
consumption and Embodied energy used amounts in Aye project on 63 apartment units with the
same area of 625 as main case in Hammads residential flat ldquoWaste amountrdquo ldquore-use of elementsrdquo
and ldquoembodied energy savedrdquo can be applied on the main case because of similarity of material
choices
IndicatorsAltertanives TRC PSM PCM PTM
Cost stability 6 9 8 9
Time stability 6 9 8 9
Recycleability of elements 3 8 7 9
Protection level 2 9 9 9
Job stability 5 8 8 8
New job creation 3 8 8 8
Quality satisfaction 5 9 8 9
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
70 | P a g e
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow)
bull Prefabricated Timber Modules indictors (PTM)
As it can be seen in table 48 there are no enough data over literature in many areas and due
to the necessities for this study a range of calculations and estimation have to be made based on the
similarity of projects among study cases and survey information Table 4 8 - First hand data over literature
Starting with Cost of the project which an ldquoestimationrdquo based on literature review information
and qualitative comparisons (John quale 2012) (Lu Aye2011) that is approximately 45000 AUD
because it proved that the cost of Timer modules is even cheaper than Steel Modules due to simplicity
of material choice and structure design The schedule of PTM building is shorter than the other
alternative because of numbers of reasons such as less weight of elements which can lead to faster
transportation loading and offload in assembly process on-site In addition the manufacturing lines
are simpler than other modular alternatives because of high repetitions and simplicity in design
For ldquocarbon emissionrdquo and ldquomaterial consumptionrdquo Aye project was used by diving on 63
apartment units which have the same area of 625 m2 as main case In terms of ldquowaste generationrdquo a
unique article was used (by Doyoon 2008) which did a LCA study on Timber modular building and the
amount of wastematerial consumed was about 9 The Noise level and Injury risk can be applied
from other modular alternative because of similarity of construction activities and equipment used
for fabrication Energy utilized during construction of Timer modules have the minimum amount in
comparison with other alternatives because of simplicity of material choice and design enhancement
so that was estimated 80MJ which is slightly less than steel modules with 86 MJ
Re-use of elements in timber modular elements was confirmed by survey among the
constructors over than 70 with a life span of 50 years Embodied Energy used was collected from
Aye case study dividing on 63 apartments units as same as other cases which equals to 65671 GJ
(Table 49) Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue)
bull Prefabricated Concrete Modules indicators (PCM)
The least focus on modular alternative was on Concrete Modules which is because of few uses
that this method has among the projects Balasbaneh study focused on a comparison between Steel
modules and Concrete modules in total project cost and LCA Table 4 10 - First hand data over literature
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury risk Energy utilized Re-use Embodied energy Emb saved
Aye 2500000 996 356 41373 691
Quale 13600
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 45000 20 39375 1580952 9 645 163 80 70 65671 691
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Balasbaneh 239380 8264
Units MLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
71 | P a g e
However the currency of this economic analysis is not as AUD (Australian Dollars) as the main
study Therefore to calculate the cost and CO2 footprint corresponding to main study case a ratio
was obtained between concrete modules amounts and steel modules in Balasbaneh study and then
multiplied to the steel modules quantities in Hammadrsquos main case and resulted project cost of
5188603 AUD and 46442 kg of CO2 emissions
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM alternatives
239380 divide 222580 = 1075478 119862119900119904119905 119903119886119905119894119900 (Balasbaneh study case)
482446 times 1075478 = 5188603 119860119880119863 Total project cost of PCM
8264 divide 9623 = 085877 1198621198742 119903119886119905119894119900
54079 times 085877 = 46442 119896119892 CO2 of PCM
The time indicator was estimated based on steel modules but with this difference that
concrete modules weight more than steel ones so that puts pressure on the transportation and
assembly phases and causes delays in the schedule as a result 24 days was predicted to finish the
project
There is no available information on the literature with specific quantitative details however
based on the qualitative structural information prefabricated concrete modules PCM because of their
similarity of material choice to conventional model have a massive material use in comparison with
Steel and Timber alternatives so that an estimated total material consumed of 20000kg assigned for
this indicator (Aye 2011) (Balasbaneh 2020)
Waste generation have a higher ratio in this alternative because of material choices which
generate more waste than other modular alternatives With this fact in mind the waste ratio
considered slightly more than steel kind with 10 (Aye 2011)
Noise level and Injury risk can be applied from other types because of similarity of equipment
and construction activities in all three modular alternatives (Hammad 2019)
Energy utilized during construction in PCM Alternative can be estimated more than steel ones
because of types of materials used in these modules and their high weight with value of 90MJ (Aye
2011)
The structural elements are ldquonotrdquo built in material which have a high recyclability potential so
that decreases the Re-use ratio to 20 approximately in comparison with other modular alternatives
(Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
72 | P a g e
Embodied energy used amount and its potential saving have the minimum value in a
qualitative comparison with other alternatives which respectively values of 800GJ and 60 were
estimated for them (Aye 2011) Table 4 11 - Final indicators for PCM
bull Traditional Reinforced Concrete (TRC) final indicators
The highest focus over the literature is to make a comparison between one of the modular
options and a traditional method which results more availability for direct data for Traditional method
The main case study is not an exception with almost half of the value are available directly such as
Project cost Time Noise level Injury risk and Energy utilized during construction which are shown in
green at table 412 (Hammad 2019) Table 4 12 - TRC first-hand data over literatures
Nevertheless still there are values that must be calculated over literature Green gas emission
indicator and Embodied Energy used were calculated form Ayersquos case study by dividing the values on
63 apartment units which results 3620635kg Co2 emission and 6033 GJ of 625 m2 area as same as
main case study (Aye 2011) (Hammad 2019)
Material consumption have the same methodology as carbon footprint with final value of
626825kg which is massively higher from modular alternatives (Aye 2011) (Hammad 2019)
Waste generation was calculated qualitatively from a literature resource called ldquoModular
Construction for Multifamily Affordable Housingrdquo by WSP which acclaims that the conventional site-
built method produces around 25 times more construction waste (WSP 2018) Thus TRC waste
generation is more than 25 times of modular ones with the value of 15
Two values of Re-use and Embodied energy saved by Re-use of elements were obtained from
Ayersquos case study respectively 22 and 322 (Aye 2011) Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow)
In general the table 414 shows the References and final indicator values that were used for decision
making process (Direct data are shown in Green Calculated data in yellow and estimated data in
blue)
Table 4 14 - Final Quantitative indicators used for decision making process
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 812298 6598 71 217 198
Akbarnejad 120000 67 84672
Aye 2281000 3949 22 38008 322
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
PSM 482446 2131 54079 138254 5 645 163 8593 50 9012 813
PTM 45000 20 39375 1580952 9 645 163 80 70 65671 691
PCM 5188603 24 46442 20000 10 645 163 90 20 800 60
TRC 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrence Ham Aye Balas Hammad Balas Aye Aye Doyoon WSP Aye Hammad Hammad Hammad Aye Aye Aye
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
73 | P a g e
Weights
The Weights (Pesos in MIVES) which are one of the most important factors in decision making
process have be assigned on the data in a way that the priority of each section in terms of efficiency
and importance can decide which value will have among the others AHP method was used to assign
weights on the data In AHP you get the weights through the subjective importance of each element
with respect to the others (Alejandro Josa 2012)
bull Weights of requirments
The importance of requirmenets was assumed based on proffessional survey among
constructors architects sales agents and clients in order to know the demands of market and make
the decision rely on what market expects from a innovative method According to the survey time
reduction is the first priority for choosing the modular methods by constructors and future clients so
than acheived 30 of weight Economic issues came after the time factor because of unconsistency
between responds about cost saving on the budget or offseting the expenses gap by tarnsportation
extra costs on the project Economic requirement has 27 of weight In some regions the priority of
choosing an innovative method are environmental emissions waste generation and recycleability of
products Therefore environmental requirement came after the economic one with 25 of weight
As it mentioned before Social and safety advantages are included in this decision making
process with respectly weights of 13 and 5 because of their less priorities among clients and market
players Table 4 15 - Requirement weights
Requirement Economic Time Environmental Safety Social
Weights 27 30 25 13 5
bull Weights of criteria
In cost and time of project which are single criteria have 100 of weights However for
instance in environmental and AHP method must be used to assign the weights based on the
importance in an environmental consideration The amount of emission that construction activities
can produce and the amount of negative effect on the global environment have been considered for
AHP method in weight assignment process Energy consumption and material consumption have the
priority to consider in LFA analysis because the consumption of primary resources have to be
minimized in a project at the first step and then the emission have to be reduced by changing the
processes etc Finally the ability to re-use and recycle and elements must be improved (Mohammad
Kamali 2017) (John Quale 2012) (Marta Gangolells 2014) Therefore Energy Consumption and
Material consumption have the most weight of 17 Embodied energy with 16 and waste generation
Greenhouse Gas emission and Recycle achieved 15 of weight At last noise Pollution took the least
priority of weights with 5 Table 4 16 - Weights of criteria
bull Weights of Indicators
Both of Economic and Time indicators divided to two sub-categories project cost and time and
their stability ratios with 80 and 20 weights by AHP method
Criteria that are single indicator obviously have 100 of weights However there are two
indicators in recycle criteria Recyclability and Re-use of elements with 40 and 60 weight
respectively Moreover Embodied Energy have is divided to Embodied energy used which is more
CriteriaEnergy
consumption
Waste
generation
Material
Consumption
Noise
pollution
Greenhouse
gas emissionRecycle
Embodied
energy
Weights 17 15 17 5 15 15 16
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
74 | P a g e
important than the other that is saving in embodied energy by re-use because as it mentioned before
in the first place the use have to be minimized and then actions such as re-use of elements have to be
done 70 of weight for Embodied energy use and 30 for Saved Embodied energy are assigned Job
stability and New job creation with weights of 50 each are the Job status indicators (Figure 411)
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software
Value function play an important role on deciding which comparative final value can each
indicator have among the other indicators for each alternative To evaluate the sustainability index
(Is) of each alternative solution value functions assigned and were used (Alarcon et al 2011) The
generic form of a value function is represented by Table 417 which allows to assess the sustainability
(satisfaction) associated with each indicator by transforming the physical units to a dimensionless
value between 00 and 10
Equation 4 1 - Functionality of value function elements
In Eq (41) B is the value of indicator(Iind) for Xmin Xmin is the minimum abscissa value in the
indicator interval assessed X is the abscissa value for the indicator assessed Pi is a shape factor which
defines whether the curve is concave (Pi lt 1) convex (Pi gt 1) linear (Pi = 1) or S-shaped (Pi gt 1) (see
figure 412) Ci approximates the abscissa at the inflexion point Ki tends towards (Iind) at the inflexion
point B the factor that prevents the function from exceeding the range (0 1) is obtained by Eq (42)
Xmax being the abscissa value of the indicator that gives a response value of 1 for increasing value
functions
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
75 | P a g e
Equation 4 2 - B value equation
Figure 4 12 - Possible forms of the value function
Due to the lack of existence of resources for assigning the specific value functions for modular
alternatives some hypotheses that can increase the feasibility and sustainability of project were
considered for the shape P K and C values to select the best form of abacus
In the other side maximum and minimum satisfaction points were selected on the
expectations of a project management view For instance in total project cost indicator case
minimum satisfaction point is 82000 AUD that is slightly more than the traditional reinforced concrete
alternative project cost (812298 AUD) because of the fact that those alternatives should be
considered as a reasonable options which can make saving in final budget Moreover the same rule
can be applied for maximum satisfaction point which is close to the Timber Modular alternative (45000
AUD) to minimize the final budget as much as possible The shape of the abacus was selected as
Convex shape (Convexa in MIVES) because even the least economic saving that an alternative can
achieve have a positive effect on the satisfaction of project and can be given any positive points in a
scale of ldquo0 to 10rdquo But the more the curve closes to the traditional alternative budget the les
satisfaction it can receive (Figure 413)
Figure 4 13 - Value function for total project cost in MIVES
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
76 | P a g e
The following Table 417 includes the value functions which were used for the rest of the
indicators Table 4 17 - Value function for indicators in MIVES
Data analysis
Indicators Values
Indicator data were translated to general normalized values shown in Table 418 amp 419 based
on the given value functions that earlier assigned This step is crucial for next analyses which will be
done to result the criteria and requirement values which lead to sustainability Indexes that can take
the multi-criteria decision As it can be seen these values have the same range of 0 to 1 so that can be
compared in with a common unit Comparisons are obvious in this level because of single value
orientation of each indicator however on following analysis there will be multi-criteria comparisons
which can achieve useful data for future decision-making process Table 4 18 - Indicators normalized values
Table 4 19 ndash Indicator normalized values
Indicators Lower limit Upper limit Max satisfaction Min satisfaction P K C Shape
Total Project Cost 30000 90000 43000 82000 05 05 79900 Concave
Cost stability 0 10 10 5 05 05 55 Concave
Total Project Time 20 75 20 68 05 05 632 Concave
Time stability 0 10 10 5 05 05 55 Concave
Energy Utilized 75 220 80 205 05 05 1925 Concave
Solid Waste 0 100 0 18 08 05 162 Concave
Material Consum 10000 70000 12000 63000 05 05 57900 Concave
Noise Level 58 78 62 72 05 05 71 Concave
CO2 32000 60000 32000 55000 05 05 52700 Concave
Recyclability 0 10 10 0 05 05 1 Concave
Re-use 0 100 60 0 05 05 20 Concave
Embodied energy 600 950 600 915 05 05 8835 Concave
Embodied saved 0 100 90 30 05 05 36 Concave
Injury risk 0 4 155 22 05 05 2135 Concave
Protection level 0 10 10 0 1 001 1 Lineal
Job stability 0 10 9 4 1 001 45 Lineal
New job creation 0 10 10 0 05 05 5 Concave
Quality Satisfaction 0 10 10 0 1 001 5 Lineal
R1C1I1 R1C1I2 R2C1I1 R2C1I2 R3C1I1 R3C2I1 R3C3I1 R3C4I1 R3C5I1
TRC 016 051 024 051 027 029 01 034 092
PSM 094 092 098 092 098 082 099 088 023
PCM 09 081 097 081 097 059 093 088 065
PTM 098 092 1 092 1 064 097 088 085
R3C6I1 R3C6I2 R3C7I1 R3C7I2 R4C1I1 R4C2I1 R5C1I1 R5C1I2 R5C2I1
TRC 073 026 1 024 024 021 02 063 05
PSM 095 094 023 095 094 09 08 092 09
PCM 092 068 064 077 094 09 08 092 08
PTM 098 084 092 085 094 09 08 092 09
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
77 | P a g e
Criteria Values
MIVES analysed each criterion by single or multi-indicator normalized values and resulted
values with a same range of 0 to 1 for following comparisons Table 4 20 - Criteria normalized values
Table 4 21 - Criteria normalized values
To begin with Project Cost (R1C1) criteria values shows that Almost three modular
alternatives performed 3 times more than the traditional method positively caused by hugely less total
project cost (R1C1I1) and great cost stability (R1C1I2) in project final budget The minimum value
belongs to PTM with 097 and slightly more than PSM and PCM is the next alternative with a value of
088 and at last TRC with 023 (Figure 414)
Figure 4 14 - Criteria normalized values
The comparison between modular alternatives in terms of which one can save time on the
schedule is close and it can be said that all three can make the project executed more than 3 times
shorter than traditional approach Timber steel and concrete options with respectively 098 097 and
094 values were compared to the conventional concrete method with 029 value (Figure 415)
R1C1 R2C1 R3C1 R3C2 R3C3 R3C4
TRC 023 029 028 029 009 032
PSM 094 097 099 083 099 088
PCM 088 094 096 059 094 088
PTM 097 098 101 064 096 088
R3C5 R3C6 R3C7 R4C1 R4C2 R5C1 R5C2
TRC 091 045 083 024 021 040 052
PSM 024 096 048 095 090 088 092
PCM 064 077 072 095 090 088 080
PTM 085 091 096 095 090 088 092
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
78 | P a g e
Figure 4 15 - Project Schedule
ldquoEnergy saving potentialrdquo in modular methods are close to the maximum satisfaction point
with timber solution and steel modules while concrete option is on the chase with 096 While
Traditional alternative only have 28 of satisfaction level
ldquoWaste generationrdquo among the alternatives have a different attitude while traditional method
with value of 029 has the most ratio of material waste production modular alternatives are
performing better where steel option have the most reduction with value of 083 and follow to that
timber and concrete options respectively 064 and 054 values PCM alternative as it said before
because of similarity of material choice to TRC have the minimum performance among the other
three (Figure 416)
Figure 4 16 - Waste generation ratios
ldquoMaterial consumptionrdquo criteria are dominated by modular methods which have a high
satisfaction with over than 09 normalized values while TRC performance can be concerning for the
primary resources with 01 normalized value
Previously on this report the fact was mentioned that off-site construction can benefit the
environment with noise reduction during construction activities based on literatures and this study
confirms this advantage by 088 values of all three modular alternatives and 032 value of traditional
RC which is less than half of modular options
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
79 | P a g e
A highlight of this study is about the comparison of CO2 Emissions of alternatives during the
constructionfabrication activities which traditional method have the minimum contamination with a
value of 091 and follow to that Timber option with 085 which is close to the TRC method Later to
that Concrete modules have a value of 064 and the minimum satisfaction belongs to the steel
modules with 024 normalized value This result bring uncertainty to the fact that modular
construction can reduce the Greenhouse gas emission to 30 over the literature review
Figure 4 17 - CO2 Emission normalized values
This study shows that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options with a value of 096 because of the material choice
repetition in element manufacturing and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution have 091 value that can confirm the concept of
recyclability for wooden modules which was mentioned by participants in professional survey as well
Figure 4 18 - Recyclability and re-use potential of alternatives
There is a discussion about the amount of embodied energy used during the lifetime of each
alternative and the potential of future saving by re-use of elements in projects which effect the total
embodied energy consumption in construction
As the Figure 419 explains traditional method has the maximum satisfaction level in terms
of consumption while steel modules have the least satisfaction of life cycle embodied energy used of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
80 | P a g e
023 PTM have a better value of 091 which shows that Timber solution can be reliable among the
others
However this study resulted that the most re-use value belongs to steel option with 095
value that and other two timber and concrete modules respectively with 085 and 077 can
compensate the gap with traditional method that has only 024 Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction total value of 096 Later
traditional reinforced concrete method with 088 still proves its abilities over other two modular
alternatives
Figure 4 19 - Embodied energy consumption and saving potential by reuse
In terms of safety modular alternatives because of their off-site nature can provide a high
satisfaction level with values of 095 in injury risks for workers and 090 protection from nature causes
which confirms the theory of safety advantage of modular construction over traditional methods from
literature studies (Figure 420)
Figure 4 20 - Safety advantage of modular construction over traditional method
Social benefits which were mentioned in literature review section also had been examined in MIVES
system and the job stability and job creation in modular construction can benefits the construction
society in significant way among the regions that have employability ratio problem
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
81 | P a g e
Figure 4 21 - Social criteria
Requirement Values
After analysis on criteria functions general values of each requirement were related to
alternatives achieved which can examinate all four construction methods to know which option is
more suitable in terms of Economic time environmental safety and social issues
The Table 422 below demonstrates the Requirements normalized values for each alternative Table 4 22 - Requirement normalized values for four indicators
bull Economic and Time requirements
As the graph illustrates Modular methods have a significant performance in economic and
time terms with the maximum values of 097 and 094 in Time and 098 and o97 in Economic
requirement for Timber and then Steel modules-based methods respectively Traditional reinforced
concrete option showed a poor functionality in cost and time of project with minimum values of o29
and 023 in order (Figure 422)
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values analysed by MIVES
Requirements Economic Time Environmental Safety Social
TRC 023 029 045 022 046
PSM 094 097 075 093 088
PCM 088 094 078 093 084
PTM 097 098 088 093 088
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
82 | P a g e
bull Environmental requirement
Generally all three modular approaches have beaten the traditional method with almost
double of normalized values in comparison
Despite the poor performance of steel modules in Greenhouse gas emissions and Embodied
Energy used in construction in total numbers proved that can provide the environmental demands
better than traditional option with a value of 075 which is third modular alternative in overall
Prefabricated Timber modules obtained the maximum value of 088 which claims not only
most economic option but environmentally friendly among other relatives and following to that
Concrete modules with value of 078 shows its liability to be chosen in case of need while the
traditional concrete method which includes most of the used materials n PCM but in a on-site plant
only can achieve a satisfaction value of 045 among the others (Figure 423)
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind
bull Safety and social requirements
The dominance of Modular construction in safety and social requirements over conventional
option can be seen in Figure 424 which can raise the possibility of modular methods to be the best
decision over the traditional option to construct this residential project As it was mentioned before
these two criteria must be considered in any decision-making process because of their high
importance in construction industry
Figure 4 24 - Modular dominance in safety and social requirements over conventional option
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
83 | P a g e
Sustainability Values (Final decision)
Finally the sustainability Indexes can be obtained to claim which alternative will be decided
as the most sustainable option for the main studyrsquos project to be build The needs of market such as
short project schedule cheaper budget reduction in environment emissions and ability to
recyclereuse safety measures and social benefits put effects on this decision as previously
mentioned
Table 423 explains that Prefabricated Timber Modules (PTM) is most sustainable alternative
among the other with a perfect normalized value of 094This could be because of its shorter schedule
of construction lowest total budget and excellency in environmental performance among the other
alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative Table 4 23 - SI (Sustainability Indexes related to four alternatives)
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This fact explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives
TRC PSM PCM PTM
SI 032 090 088 094
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
84 | P a g e
5 Conclusions Decision making process
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria etc However to find out how much practical these benefits are in the market several trade-
offs must be done by professional tools such as project management software programs which can
take decisions based on the input data that receive MIVES software was used in this study to
examinate these benefits The resources for this type of studies are limited due to the lack of focus or
newfound nature of this subject and only five of them were selected because of their variety of their
criterion studies reliability and accuracy of data Requirements criteria indicators and weights that
were used in MIVES had been selected based on demands of market and professional opinions
received from the survey and availability of data over references After assigning the value functions
which are related to satisfaction level on each criterion (For instance cost reduction time saving and
minimization of emissions) normalized values were achieved that can be compared between
alternatives with range of 0 to 1
Conclusions and discussion
ECONOMIC ndash TIME discussion
bull Decision-making result
Generally all three modular alternatives have beaten the traditional method with almost
double of normalized values Modular methods had a significant performance in economic and time
terms with the maximum values in Time and Economic requirements for Timber and then Steel
modules Traditional reinforced concrete option showed a poor functionality in cost and time of
project with minimum values
Literature reviews information
These Results confirm the 50 of time saving in projectrsquos schedule (McKinsey amp Company
report 2019) and 20 of cost reduction on the budget which was mentioned also in numbers of
literatures
Professional survey confirmation
In addition the claims from professional participants in survey about the 50 cost reduction
due to the added value of every hour of work in comparison with traditional stick and build on-site
method can be approved even far more those expectations
ENVIRONMENTAL discussion
bull Recyclability and re-use potential
This study showed that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options because of the material choice repetition of
elements in manufacturing line and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution can confirm the concept of recyclability for wooden
modules which was mentioned by participants in professional survey as well
bull Embodied energy used and saving by re-use
There is a discussion over the literature and survey participants about the amount of
embodied energy used during the lifetime of each alternative and the potential of future saving by re-
use of elements in projects which effect the total embodied energy consumption in construction
where one of the companies acclaims that ldquoour homes are not positive in energy consumption
aspectrdquo Traditional method has the maximum satisfaction level in terms of consumption while steel
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
85 | P a g e
modules have the least satisfaction of life cycle embodied energy used PTM have a better value of
091 which shows that Timber solution can be reliable among the others However this study resulted
that the most re-use value belongs to steel option and other two timber and concrete modules
respectively can compensate the gap with traditional method Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction Later traditional reinforced
concrete method still proves its abilities over other two modular alternatives
bull Greenhouse gas emission
Despite the poor performance of steel modules (PSM) in Greenhouse gas emissions that bring
uncertainty to the fact that modular construction can reduce the Greenhouse gas emission to 30
over the literature review and Embodied Energy used in construction proved that can provide the
environmental demands better than traditional option which is third modular alternative in overall
comparison
bull Most environmentally friendly alternative
Prefabricated Timber modules obtained the maximum value which achieves not only most
economic option but environmentally friendly among other relatives Following to that Concrete
modules shows its liability to be chosen in case of need while the traditional concrete method which
includes most of the used materials of PCM but in an on-site plant only can achieve the minimum
value
Comparison with literature review information and survey outputs
This comparison explains the truth about the concept of being environmentally friendly about
modular construction that have been mentioned in various scientific articles (McKinsey amp Company
report 2019) (M Kamali 2016) and the survey results which confirmed the concept in real cases at
the market over years of experience
SAFETY AND SOCIAL dominance by modular methods
The dominance of Modular construction in safety and social requirements over conventional
option was resulted which can raise the possibility of modular methods to be the best decision over
the traditional option to construct this residential project As it was mentioned before these two
criteria must be considered in any decision-making process because of their high importance in
construction industry Social benefits which were mentioned in literature review section also had been
examined in MIVES system and the job stability and job creation in modular construction can benefits
the construction society in significant way among the regions that have employability ratio problem
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES
Prefabricated Timber Modules (PTM) is most sustainable alternative among the other with a
perfect normalized value of 094This could be because of its shorter schedule of construction lowest
total budget and excellency in environmental performance among the other alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This result explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
86 | P a g e
Effective external factors on decision
The decision was made for the best alternative in terms of sustainability for a specific
residential case located in Sydney Australia among three modular options and one traditional
method However there are factors which can affect the final decision obviously Such as the location
of the project which the availability of primary resources can change the or alternatives or number of
indicators The local market and their demands for specific products can be crucial for choosing the
best method which affect the priorities of weights Regulation of every regions as it was mentioned
before can change the project requirements and indicators
The type of the project was a residential building that has its own characteristics but for
instance a school or hospital project would demand a higher functionality and lifetime because of their
distinctive operation kind and evidentially can be considerable in decision-making process to the end
step Special project due to their unique requirements often do not consider all criterions For
instance emergency health stations demanded during the Virus pandemic period have their own
material choose design enhancement and priorities on requirements
Future studies
Due to novelty of this subject there are numbers of studies still remained without coverage
which might be studied in future
Decision making study on two real projects with the input data of professional
modular and traditional constructors
Due to the lack of information over literature there were so many elements that have been
estimated by hypothesis and survey information therefore it is crucial to find these data in order to
do a precise study with real numbers These data can be obtained by requests to industry players to
have access of real project details including budget schedule material consumptions etc By this
action the liability of the study can be improved and accurate results can be achieved Thus a
decision-making process can be done to find out which alternative can be more sustainable
Technological studies about the production line of a modular off-site plant by factory
and on-site visits
There are still uncertainties about the status of use of automation productivity rate etc which
have to be analysed closely Modular construction was suggested as an example of industrialization in
construction industry to improve the productivity rate but corresponding to past survey the majority
of constructors are not benefiting from automation in their production lines and assembly processes
A study is needed on different phases of a project that have to be monitored and analysed scientifically
in order to find challenges errors and possible solutions to make this method even more sustainable
A survey about challenges in modular construction and its possible solutions to find
adequate solutions
Challenges have to focused more on this method because its players are still suffering from
the incompatibility of construction industry and the projectrsquos old conditions with innovative solutions
Series of interviews with experts factory visits etc have to be done to hear the voices of them and
then researchers to find solutions to update the industry and help them for growth
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
87 | P a g e
Recommendations
Cooperation between industrial players and scientific researchers in offsite
construction
Numbers of contrasts where found in the data and results among literatures professional
participants of survey and the decision-making study which shows a poor status of cooperation
between scientific researchers and professional players in the construction industry It is obvious that
the real data from the constructors designers etc in real projects are more reliable than scientific
estimation which in this case were based on BIM models and approximate calculations without any
interruption effects of common challenges in industry There were few participants who did not want
to share their project details in public or even education purposes or in a case one of the most
innovative players in modular industry responded their lack of available time to respond the survey
by direct email These attitudes can increase the gap between two vital elements for improvement
which are science and industry in construction society and to reduce it cooperation must be increased
specially in off-site society
Education about industrialization in construction and its alternatives
The idea of lack of education among engineers and architects who enter the professional
society about off-site construction methods was proved by the collected information from survey
participants which can cause problems in the projectrsquos design coordination and execution processes
These series of errors must be resolved by updating the education resources about innovative
methods such as off-site construction industrialization in construction concept rather than traditional
on-site methods that still occupy most of the educational courses these actions can improve the
common challenges in construction industry such as productivity problem and sustainability rate by
encouraging the researchers even far beyond the boundaries of investigations and make the way
possible to find more innovative solutions such as robotic fabrication 3D concrete printing etc
Establishing international and regional adequate codes
Use of automation is suggested by the researchers and industry players to raise the
productivity and sustainability in construction as the other industries which resulted positively
However constructors and manufacturers are suffering from a lack of exitance of international united
codding for their production line and boundaries and uncertainties by local regulations
To resolve these issues participants addressed an international code similar to what on-site
traditional methods have which the responsibility of creation of these codes are on the shoulders of
researchers and professional experts with a mutual partnership that is only possible with cooperation
of industry with science as it mentioned before
Synchronizing the contract conditions with modular construction conditions
There are numbers of problems in terms of contract conditions such as misunderstanding by
final client who is the end home buyer who ldquobelieves the factory to be the builder and the actual
independent builder to be a sales agent for the factoryrdquo one of the participants mentioned A
recommended solution for this problem is to define the relationships between the participants of
projects their responsibilities For instance requiring the builders customer to sign a disclosure
acknowledgement from that describes the relationship in detail In addition there is a lack of quality
partners on site The problem starts when on-site participants realize the advantages of modular
construction they tend to increase their prices for services which can increase the final prices of
project Another challenge which modular projects can face is the lack of delivery of project on agreed
time with an unacceptable quality of on-site execution The professionals answered that the
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
88 | P a g e
responsibility of ensuring that the work is done properly belongs to the builder which any ldquodelays in
this can result in postponed transport of product and interest through demurrage chargesrdquo
These problems must be solved by defining unique types of contracts that are adapted with
the off-stie construction nature and be obeyed by all the participants globally
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc
The only value that the market considers choosing modular method over traditional
construction is to be cheaper while majority of people the media and even professional engineers do
not understand the capabilities of modular construction Many people continue to confuse this form
of construction with HUD on frame products Another wrong perception that the publicmarket
believes is that the prefabrication methods limits the design options while some players believe that
the reverse is the case Therefore by using one of the main advantages of modular construction which
is shorter schedule the market can be dominated by modular projects and the more cases they
deliver the more recognised this method would be among the public and at the end the superior
nature of modular approach can be proved Another solution is a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Many of these wrong perception and misunderstandings can be
clarified by well-organized advertisements about several advantages that modular construction have
in comparison with conventional methods
Changes in financial strategies and adapting them with off-site construction nature
Financial assists which are crucial for kind of projects that are dependent to these aids are
not harmonized with modular project processes where there are argues that until the first deliveries
of elements to the site location and their assembly these aids will not be reachable This issue creates
pressure on cash flow of project where bank finance is involved Changes in contract conditions and
education for financial supporters are recommended solutions to improve the partnerships in
projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
89 | P a g e
6 References 1) Balasbaneh AT Ramli MZ A comparative life cycle assessment (LCA) of concrete and
steel-prefabricated prefinished volumetric construction structures in Malaysia Environ Sci
Pollute Res (2020) httpsdoiorg101007s11356-020-10141-3
2) Doran D and Giannakis M (2011) An examination of a modular supply chain a
construction sector perspective Supply Chain Management Vol 16 No 4 pp 260-
270 httpsdoiorg10110813598541111139071
3) Lawson RM Ogden RG Bergin R 2012 Application of modular construction in high-rise
buildings Journal of Architectural Engineering httpsdoi101061(ASCE)AE1943-
55680000057
4) Diez R et al (2007) lsquoAUTMOD3 The Integration of Design and Planning Tools for Automatic
Modular Constructionrsquo International Journal of Advanced Robotic Systems httpsdoi
1057725671
5) Lee J Park M Lee H ampamp Hyun H (2019) Classification of Modular Building
Construction Projects Based on Schedule-Driven Approach Journal of Construction
Engineering and Management 145(5) 04019031 httpsdoi101061(asce)co1943-
78620001656
6) Barbosa F Woetzel J Mischke J Ribeirinho M Sridhar M Parsons M Brown S
(2018 July 09) Reinventing construction through a productivity revolution Retrieved
September 28 2020 from httpswwwmckinseycomindustriescapital-projects-and-
infrastructureour-insightsreinventing-construction-through-a-productivity-revolution
7) Quale J Eckelman MJ Williams KW Sloditskie G and Zimmerman JB (2012)
Construction Matters Comparing Environmental Impacts of Building Modular and
Conventional Homes in the United States Journal of Industrial Ecology 16 243-253
httpsdoi101111j1530-9290201100424x
8) Horwitz-Bennett Barbara (2020) Rising to the challenge sl Modular Building Institute
(MBI)
9) Lu N amp Korman TM (2010) Implementation of Building Information Modeling (BIM) in
Modular Construction Benefits and Challenges
10) Institute Modular Building 2019 Permanent Modular Construction Canada Modular
Building Institute
11) Josa A (2012) Introduccioacuten a MIVES y el anaacutelisis multicriterio Jornada sobre la Importancia
de un meacutetodo para la toma de decisiones modelo MIVES para una ingenieriacutea sostenible
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
90 | P a g e
12) Aye L Ngo T Crawford R H Gammampila R amp Mendis P (2012) Life cycle greenhouse
gas emissions and energy analysis of prefabricated reusable building modules Energy and
buildings 47 159-168
13) Kamali M amp Hewage K (2016) Life cycle performance of modular buildings A critical
review Renewable and sustainable energy reviews 62 1171-1183
14) Lawson M Ogden R Goodier C (2014) Design in Modular Construction London CRC
Press httpsdoiorg101201b16607
15) Generalova E M Generalov V P amp Kuznetsova A A (2016) Modular buildings in modern
construction Procedia engineering 153 167-172
16) Thompson J (2019) Modular Construction A Solution to Affordable Housing Challenges
Cornell Real Estate Review 17(1) 21
17) Modular construction for multifamily affordable housing (2018) WSP
httpscdnymawscomwwwnibsorgresourceresmgrosccepa-modular-construction-
forpdf
18) Hammad A W A amp Akbarnezhad A (2017) Modular vs conventional construction a
multi-criteria framework approach In ISARC Proceedings of the International Symposium on
Automation and Robotics in Construction (Vol 34) IAARC Publications
19) Ferdous W Bai Y Ngo T D Manalo A amp Mendis P (2019) New advancements
challenges and opportunities of multi-storey modular buildingsndashA state-of-the-art review
Engineering Structures 183 883-893
20) Bertram N Fuchs S Mischke J Palter R Strube G amp Woetzel J (2019) Modular
construction From projects to products McKinsey amp Company Capital Projects amp
Infrastructure 1-34
21) Hsu P Y Aurisicchio M amp Angeloudis P (2020) Optimal logistics planning for modular
construction using multi-stage stochastic programming Transportation Research Procedia
46 245-252
22) Rausch C Nahangi M Perreault M Haas C T amp West J (2017) Optimum assembly
planning for modular construction components Journal of computing in civil engineering
31(1) 04016039
23) Connor G Jones C E amp Finney S J (2014) Easing future low voltage congestion with an
AC chopper voltage regulator httpsdoi 101061(ASCE)CO1943-78620001001
24) Ahn Y H amp Kim K T (2014) Sustainability in modular design and construction a case
study of lsquoThe Stackrsquo International Journal of Sustainable Building Technology and Urban
Development 5(4) 250-259
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
91 | P a g e
25) Gunawardena D Mendis P Ngo D Aye L amp Alfano J (2014) Sustainable prefabricated
modular buildings httpsdoi 10131402148473920
26) Olearczyk J Al-Hussein M Bouferguene A amp Telyas A (2009) Virtual construction
automation for modular assembly operations In Construction Research Congress 2009
Building a Sustainable Future (pp 406-415)
27) Woźniak-Szpakiewicz E (2016) EU migrant crisis and increasing demand for modular
construction modular social housing complex for refugees in Munich In Back to the Sense
of the City International Monograph Book (pp 921-931) Centre de Poliacutetica de Sogravel i
Valoracions
28) Wunderlich-Malec 2019 The Modular Solution to Reduce Total Construction Costs
httpswwwslidesharenetJoelGil2wuderlich-malec-engineering-modular-construction
29) HAMMAD AWA AKBARNEZHAD A WU P WANG X and HADDAD A 2019 Building
information modelling-based framework to contrast conventional and modular construction
methods through selected sustainability factors Journal of Cleaner Production [en liacutenea] vol
228 pp 1264ndash1281 ISSN 0959-6526 DOI httpsdoiorg101016jjclepro201904150
Disponible en httpwwwsciencedirectcomsciencearticlepiiS0959652619312296
30) HONG J SHEN GQ LI Z ZHANG B and ZHANG W 2018 Barriers to promoting
prefabricated construction in China A costndashbenefit analysis Journal of Cleaner Production
[en liacutenea] vol 172 pp 649ndash660 ISSN 0959-6526 DOI
httpsdoiorg101016jjclepro201710171 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS0959652617324782
31) LOPEZ D and FROESE TM 2016 Analysis of Costs and Benefits of Panelized and Modular
Prefabricated Homes Procedia Engineering [en liacutenea] vol 145 pp 1291ndash1297 ISSN 1877-
7058 DOI httpsdoiorg101016jproeng201604166 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS1877705816301734
32) NEELAMKAVIL J 2009 Automation in the Prefab and Modular Construction Industry [en
liacutenea] Sl sn DOI 1022260ISARC20090018 Disponible en
httpwwwiaarcorgpublicationsproceedings_of_the_26th_isarcautomation_in_the_pref
ab_and_modular_construction_industryhtml
33) SANTIAGO M ALBERTO J MARIA NJ and PATRICIA G 2008 Building industrialization
robotized assembly of modular products En M ONORI (ed) Assembly Automation [en
liacutenea] vol 28 no 2 pp 134ndash142 ISSN 0144-5154 DOI 10110801445150810863716
Disponible en httpsdoiorg10110801445150810863716
34) McGeorge D amp Zou P X (2012) Construction management new directions John Wiley amp
Sons
35) Fieldwire (2018) Why the Construction Industry Is Stuck in the Past
httpswwwfieldwirecomblogis-construction-stuck-in-the-1960s
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
92 | P a g e
36) Construction industry - Office for National Statistics (2019) ONS
httpswwwonsgovukbusinessindustryandtradeconstructionindustry
37) Timmer M P O Mahony M amp Van Ark B (2007) EU KLEMS growth and productivity
accounts an overview International Productivity Monitor 14 71
38) Smith A (2011 September 22) Agile and Lean for Construction SlideshareNet
httpswwwslidesharenetadrianlsmithagile-and-lean-for-construction-9384237
39) The massive opportunity of digitization in Engineering amp Construction (2019)
JourneyappsCom httpsjourneyappscomblogmassive-opportunity-digitization-
engineering
40) Tapscott D amp Tapscott A (2018) Blockchain Revolution How the Technology Behind
Bitcoin and Other Cryptocurrencies Is Changing the World (Reprint ed) Portfolio
41) Can Blockchain Fix the Construction Industryrsquos Productivity Problem (2018) Enstoa
httpsenstoacomblogcan-blockchain-fix-construction-industrys-productivity-problem
42) Itanola M (2019 June 5) Hey Quantity Surveyor is BIM going to take your job Blaze
Threads httpswwwblazethreadcomhey-quantity-surveyor
43) BIM Community (2017) Remodeling Construction Industry with Digitization BIM and
Reality Capture httpswwwbimcommunitycomnewsload563remodeling-
construction-industry-with-digitization-bim-and-reality-capture
44) Kolarevic B (2003) Digital production Architecture in the digital age design and
manufacturing 38-63
45) Labonnote N Roslashnnquist A Manum B amp Ruumlther P (2016) Additive construction State-
of-the-art challenges and opportunities Automation in construction 72 347-366
46) Kapoutsis A C Chatzichristofis S A Doitsidis L de Sousa J B Pinto J Braga J amp
Kosmatopoulos E B (2016) Real-time adaptive multi-robot exploration with application to
underwater map construction Autonomous robots 40(6) 987-1015
47) Khoshnevis B (2004) Automated construction by contour craftingmdashrelated robotics and
information technologies Automation in construction 13(1) 5-19
48) R Alice (2019) CRYSTAL PALACE SHOWER TALK httpsbloginoxstylecomencrystal-
palace
49) Eba (2014) HISTORY ldquoballoon framingrdquo the first prefabricated building system (US)
Architecture for the 99 httpslikemyplacewordpresscom20140214history-balloon-
framing-the-first-prefabricated-building-system-us
50) Peter Goumlssel Arnt Cobbers Oliver Jahn (2012) A Brief History of Prefab ArchitectureWeek
httpwwwarchitectureweekcom20121003design_1-1html
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
93 | P a g e
51) Merin G (2018) AD Classics Habitat 67 Safdie Architects ArchDaily
httpswwwarchdailycom404803ad-classics-habitat-67-moshe-safdie
52) Sveiven M (2018) AD Classics Nakagin Capsule Tower Kisho Kurokawa ArchDaily
httpswwwarchdailycom110745ad-classics-nakagin-capsule-tower-kisho-kurokawa
53) Modular Building Experience | Deluxe Modular (2020)
httpswwwdeluxemodularcomexperience
54) Applications | Modular Construction | Bathroom Pods (2020) Howick Ltd
httpswwwhowickltdcomapplicationsmodular-constructionbathroom-pods
55) Project types (2018) Panel built httpswwwpanelbuiltcomblogmodular-building-types
56) Mobile Mini Merger - WillScot (nd) Willscot httpswwwwillscotcomAboutMobile-
Mini-Merger
57) Teague L (2017) Urbantainer breaks down the negative stereotypes of modular building
Frameweb httpsframewebcomarticleurbantainer-breaks-down-the-negative-
stereotypes-of-modular-building
58) Modular construction (nd) SteelconstructionInfo
httpswwwsteelconstructioninfoModular_construction
59) Modular V (2020) What Is Modular Building Construction Your Ultimate Guide Vanguard
httpsvanguardmodularcomabout-modular
60) Permanent Modular Construction Annual Report 2019 | Modular Building Institute (2019)
MBI httpswwwmodularorgHtmlPageaspxname=pmc-2019-home
61) Modular Construction Foundation (2020) Triumph Modular
httpswwwtriumphmodularcomabout-triumphour-servicesconstruction-
managementfoundations
62) Weights and Dimensions (2020) ITF httpswwwitf-oecdorgweights-and-dimensions
63) Sajip J (2019) Modular Construction A Sustainable Building Method NY-Engineers
httpswwwny-engineerscomblogmodular-construction-a-sustainable-building-
methodWeights and Dimensions (2020 August 28) ITF httpswwwitf-oecdorgweights-
and-dimensions
64) Muresan F (2019) What is Modular Construction NY-Engineers httpswwwny-
engineerscomblogwhat-is-modular-construction
65) ADVANTAGES of using SurePods prefabricated modular bathroom pods (nd) SurePods
httpswwwsurepodscomspeed
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
94 | P a g e
66) EasyPads - The easy-to-use foundation system for modular buildings (2019 March 23)
EasyPads - Foundation System httpseasypadscouk
67) Honrubia M amp Mendonccedila A (2019 June 18) The Benefits of Reusable and Modular
Constructions Ennomotive httpswwwennomotivecomreusable-modular-
constructions
68) Cosentino (2020) Discover Cosentino and all the characteristics of its materials
httpswwwcosentinocom
69) Al-Hussein M Manrique J D amp Mah D (2009) North Ridge CO2 analysis report
comparison between modular and on-site construction University of Alberta Canada
70) Vickers H (2017) Modular construction 4 health and safety benefits Building 4 Education
httpsb4edcomArticlefour-health-and-safety-benefits-of-modular-construction
71) PRISM (2020) HGA and The Boldt Company build STAAT ModTM critical care units to
address the COVID-19 hospital bed shortage PRISM Modular construction 4 health and
safety benefits Building 4 Education httpsb4edcomArticlefour-health-and-safety-
benefits-of-modular-construction
72) Harrouk C (2020 September 28) Mayor of London Launches Housing Design App to
Transform Construction ArchDaily httpswwwarchdailycomauthorchristele-harrouk
73) Schoenborn J (2012) A case study approach to identifying the constraints and barriers to
design innovation for modular construction (Doctoral dissertation Virginia Tech)
74) Casas prefabricadas inHAUS (nd) servicio post-venta casa modular archivos InHAUS
httpscasasinhauscomfranceestagservicio-post-venta-casa-modular
75) Catalunya U U P (nd) MIVES mdash Departamento de Ingenieriacutea Civil y Ambiental mdash UPC
Universitat Politegravecnica de Catalunya UPC httpsdecaupceduesproyectosmives
76) Kim D (2008) Preliminary Life Cycle Analysis of Modular and Conventional Housing in
Benton Harbor MI (Doctoral dissertation)
77) Gangolells M Casals M Forcada N amp Macarulla M (2014) Analysis of the
implementation of effective waste management practices in construction projects and sites
Resources conservation and recycling 93 99-111
78) Alarcon B Aguado A Manga R amp Josa A (2010) A Value Function for Assessing
Sustainability Application to Industrial Buildings Sustainability 3(1) 35ndash50
httpsdoi103390su3010035
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
95 | P a g e
Anexo 1
a) Indicators resources
o Prefabricated Steel Modular (PSM)
Table A1 1 ndash Cost of project PSM (Hammad 2019)
Table A1 2 -Time of project PSM (Hammad 2019)
Table A1 3 - Energy utilized during construction (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
96 | P a g e
Figure A1 1 - Injury risks for workers (Hammad 2019)
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
97 | P a g e
Figure A1 3 - Co2 amount (Aye 2011)
o Prefabricated Concrete Modular (PCM)
Figure A1 4 - Total project cost (Balasbaneh 2020)
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
98 | P a g e
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter)
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020)
o Prefabricated Timber Modular (PTM)
Figure A1 8 - Co2 emission (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
99 | P a g e
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
o Traditional Reinforced Concrete (TRC)
Table A1 6 6 - Projects cost (Hammad 2019)
Table A1 7 - Projects schedule (Hammad 2019
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
100 | P a g e
Table A1 8 - Energy utilised during construction process (Hammad 2019)
Figure A1 9 - Injury risks for workers (Hammad 2019)
Figure A1 10 - Noise level (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
101 | P a g e
Figure A1 11 - Greenhouse gas emission (Aye 2011)
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
102 | P a g e
Anexo 2 1 Survey Q amp A
Q How many years of experience do your company have in modular construction
industry Table A2 1 - Professional experience of the company
Company Responses
A 10-15
B 10-15
C 20-30
D 20-30
E 30-50
Q How many years of experience do you have in the modulartraditional construction
and what is your job position Table A2 2 - Personal experience of participant
Company Responses
A 15 years
B 13 years sales manager
C 30 years of which the last 25 have been as design architect
D Quantity Surveyor
E 3 years Foreign Trade Manager
Q What types of modules your company products in terms of material Table A2 3 - Type of modules
Company Responses
A Wood Steel
B Wood
C Wood
D Wood
E Counter and Fibber cabins Steel
Q Which types of projects you did so far Table A2 4 - Type f projects
Company Responses
A Residential houses
B Schools Residential houses Commercial buildings
C Residential houses
D Schools Residential houses Hospital Commercial buildings
E Schools Residential houses hospital Commercial buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
103 | P a g e
Q Num of employees num of factories and num of modules build Table A2 5 - Characteristics of production range
Company Responses
A 80 employees 1 factory 200 modsyear
B 130 1 490
C 15
D 50 Employees 2 factories 80 build
E 250 employees 2 factories 100000 m2 prefabricated 5000 containers 1000 cabinets TURKEY
Q What was your motivation to choosework in modular construction Table A2 6 - Motivation for doing modular construction
Company Responses
A High demands in market and lack of provide Innovation
B Economic profit
C Environmental benefits High demands in market and lack of provide Innovation Shorter construction schedule due to need Economic profit
D Shorter construction schedule due to need Innovation
E Economic profit
Q Do you have sup-contracts for your panels or they had built in your factories what
is the reason for this decision Table A2 7 - Panel production conditions
Company Responses A build our own
B PE design and approvals fire suppression design and installation ceramic tile Energy Star design and inspection are all subcontracted
C All built in house in our own workshop We have developed our own unique systems which are not available elsewhere
D build in factory - programme cost
E
EPS isolated panels are produced in our factories The other are being purchased from domestic market Standard is EPS isolation and its fixed costs are lower because of quantity The others are not standard investment in production is not feasible
Q What is the level of automation technologies you use in off-site and on-site
production and assembly Table A2 8 - Level of automation
Company Responses
A Extraordinarily little today investing in this heavily this year want to get to 80
B 20
C Off-site 60 on site 20
D 20
E 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
104 | P a g e
Q Does A modular project have a smaller number of labours Less wages of salary off-
site and on-site due to specialization of workforce Does the more value added in
each hour of work can compensate Table A2 9 - Laboral status
Company Responses
A Fewer labour hours and at less cost per hour 1 hour in the factory is equal to 4 on site
B Prefabricated systems-built modular construction generally has a smaller on-site labour force for a shorter period
C Labour similar but more efficient working off site
D Yes (less no of workers and wages) - no need for special work force
E -
Q Do you have any case of recycle and reuse the structuralnon-structural elements in
your projects Table A2 10 - Recycle and Re-use
Company Responses
A Yes
B Yes
C No
D No
E Yes
Q Do you upgrade the modules with other environmentally friendly technologies such
as solar panels in your projects Please give us some examples Table A2 11 - Innovative technology integration
Company Responses
A Our homes are all self-powered only company in the world to be doing this
B
This factory allows for site installation of solar panels and other energy savings processes on site by the independent builderbuyer of our modular building materials Modular makes the most sense to be used by architects and builders with environmentally friendly tech
C
Modules (flat packed floor wall and roof components) are constructed of ply and highly insulated with non-petroleum-based insulation (recycled glass as a fibre) Solar panels fitted as an add on to completed building
D None yet not been asked
E Solar technology is YES
Q Automation in off-site production generates less or more waste of material There
are some argues about less waste generation in manual activities because of better
sense of material resistance by normal labour (wooden material for instance) Table A2 12 - Automation status on waste generation
Company Responses
A we are not automated yet but believe automation will be much more efficient use of materials
B In our experience as a custom modular manufacturer automation has a significant cost that may not be recoverable for many months if not years- millions of dollars in cost of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
105 | P a g e
components set up and training versus hourly wage and benefits of trained factory workers
C Waste is much reduced and a proportion of the waste is remanufactured to smaller items or sold on to handymen
D Would be less waste but we do not use much automation
E -
Q How much reduction does off-site modular construction has in generating ldquowasterdquo in
comparison with traditional construction methods Table A2 13 - Reduction of waste
Company Responses
A 70 less waste
B I am unable to provide an answer to this question
C
As we are timber people emissions are low regardless of construction methods Steel and concrete use are kept to a minimum and these are the high emission materials
D We are still working on our carbon footprint
E 15 less carbon emission
Q How much reduction has in ldquoenergy consumptionrdquo off-site in comparison with
conventional on-site construction What about during the operation phase Table A2 14 - Energy consumption status
Company Responses
A Our homes are not positive from an energy perspective
B
Energy consumption of a factory is known and relatively constant on a weekly monthly and annual basis The modular components for a two-box ranch style house require 3 workdays on our factory floor and 4 more days in final finish prior to shipment A competent and experienced modular builder can many times finish the entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-built house could require as much as 4 months for the same completion
C Not assessed but doubt there is much difference
D We are still working on our carbon footprint
E 30 energy saving
Q Did you deliver any projects for providing emergency services in Covid-19 period You
can mention the projects in the other section Table A2 15 - Delivery of projects in COVID-19 pandemic period
Company Responses
A No
B No
C No
D No
E Yes
Q Did you construct any projects for world aid organizations and charities You can
mention them in the other section
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
106 | P a g e
Table A2 16 - Aid organization project delivery
Company Responses
A No
B No
C No
D No
E Yes
Q Do you offer post-sale services to your clients Table A2 17 - Post-sale services to client
Company Responses
A Yes
B No
C Yes
D Yes
E Yes
Q How much was your initial costs estimate (Factory set up etc) How long was the
investmentrsquos payback period Table A2 18 - Initial costs
Company Responses
A 20 million Canadian dollar 5-year payback
B What costs Factory set up or cost of modular product sold to builders What about labour engineering transportations etchellip
C The business has been building up over decades so it is not possible to isolate specific costs
D -
E 15 million USD 5 years
Q Which factors can change the initial costs Table A2 19 - Effective factors on initial costs
Company Responses
A Level of automation Product types and production range Less sub-contracts Site location
B Design of modular building- ie roof system high wind heavy snow loads etchellip Product types and production range Site location
C Financing Level of automation Product types and production range Less sub-contracts
D Level of automation Product types and production range Site location
E Level of automation Product types and production range
Q Can component re-use building portability and the life cycle value of materials be
used as a strategy to ldquocompensaterdquo for higher initial construction costs Table A2 20 - Re-use effect on budget
Company Responses
A -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
107 | P a g e
B
We use many lumber cut-offs PVC drainpipes and conduit and dry wall pieces over many modular orders Unusable drywall shingle and PVC pieces are collected and sent out for recycling Wood is collected and recycled into mulch product or used for heating by others
C Not easily Our methods (flat pack) due not lend themselves to building portability
D -
E 50 years life span of the products
Q Which factors did you consider for choosing modular construction over traditional
method Table A2 21 - positive factors about modular construction to be chosen
Company Responses
A traditional construction is broken
B
Speed ease and cost of overall construction Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
C Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
D Transportation costs and boundaries Local salary wages
E Transportation costs and boundaries Local salary wages Environmentally friendly
Q Do use BIM in your projects what are the challenges in using BIM Table A2 22 - Use of BIM in projects
Company Responses
A 100 BIM from conceptual to finished models
B No
C No
D No
E No
Q What effects the production line can have on the design Are there any boundaries
on the architectural design Table A2 23 - Influence of production line on design
Company What effects the production line can have on the design Are there any boundaries on the architectural design
A No you just need to design with our subassemblies in mind
B This factory maximum module dimension capability is 15rsquo9
C Workshop prefabrication gives the architect far more design freedom
D Width of building for transport to make economically viable
E No
Q Is there any lack of knowledge from architects or design engineers in modular industry
about production line processes transportation limitations etc
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
108 | P a g e
Table A2 24 - Lack of knowledge among experts
Company Responses
A Yes
B No
C NA
D Yes
E Yes
Q How state transport regulation and approval can harm the projects in cost and time
Have you experience delays in your schedules because of those Table A2 25 - Transportation regulation effect on projects
Q Does the concept of transportable materials add extra costs on the project Do the
reduction of material waste and multiple discounts can ldquocompensate the lossrdquo Table A2 26 ndash Transportable material choice and its effects
Company
Does the concept of transportable materials add extra costs on the project Do the reduction of material waste and multiple discounts can ldquocompensate the lossrdquo
A Transportation costs are offset by speed of production and reduced financing costs for the project
B Not significantly
C See 26 The reverse applies
D No
E No
Q What are the difficulties in using automation in off-site production processes Table A2 27 - Challenges of using automation
Company Responses
A Codding Integration with advanced software
B Cost
C -
D Integration with advanced software
E Codding Cost Lower salaries of manual processes by labour
Company
How state transport regulation and approval can harm the projects in cost and time Have you experience delays in your schedules because of those
A Yes Some areas are slow to respond
B
Yes Some states in the US are more difficult to ship oversized and ldquosuper loadsrdquo through This adds both time and expense to the projects
C No Our company prefabricates and flat packs so all components are within or close to legal load limits
D No
E Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
109 | P a g e
Q Which problems exist in modular construction in terms of contracts What are the
solutions Table A2 28 - Contract condition in modular industry
Q What are the challenges in defining responsibilities among participants of a project
due to the changing most of the activities to precast solutions Table A2 29 - Participation status in modular projects
Company
What are the common errors than can harm the synchronization of productivity between off-site production transportation and on-site installation progress For instance less demands on-site caused
A Lack of quality partners on site that see the benefits of modular and therefore increase their pricing
B
The builder owns the responsibility to ensure that site work is done on time and correctly Delays in this can result in postponed transport of product and interest through demurrage charges
C Provided control is tight none
D -
E -
Q Considering all components are prefabricated offsite what is the role of an outside
general contractor Table A2 30 - Role of outside general constructor
Company Responses
A will always need some component of site work to complete the project
B
An outside general contractor is the independent builder The modular factory is a material vendor to the general contractor The general contractor is responsible for all site work and permits as well as storage- installation- and finish of the modular product forming the house or structure they are building
C We do not use outside general contractors All stages from earliest concept design to completed building are in house
Q How often advantageous changes must be done in the production line and what are
the challenges
Company Which problems exist in modular construction in terms of contracts What are the solutions
A Every state has a different building code need a universal code
B
In some cases the end home buyer believes the factory to be the builder and the actual independent builder to be a sales agent for the factory Our company addresses this through accuracy in the relationship described on our website and social media as well as requiring the builders customer to sign a disclosure acknowledgement from that describes the relationship in detail
C Banks do not recognise work done until it is erected on site This creates cash flow pressure where bank finance is involved
D -
E Delivery on time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
110 | P a g e
Table A2 31 - Changes in production line and its effects
Company Responses
A Slows down production
B This company incorporates changes to product materials or procedures between orders A change in process will not occur that affects only some of the components of an order
C Not sure I can answer that ion the space All means of production have advantages and challenges We have chosen methods and stick to them
Q Do you have sub-contracted players involved in your project for site preparation and
foundation phase etc why Table A2 32 - Site preparation status
Company Do you have sub-contracted players involved in your project for site preparation and foundation phase etc why
A Yes Because we are selling in many geographic areas we need local representation
B No This is the responsibility of our customer- the general contractorindependent builder
C Yes Under direct supervision Their equipment is expensive and not portable It makes sense to use local contractors for footings
D -
E Yes
Q If the onsite foundation is constructed by an outside general contractor are there
additional challenges at the interface in terms of a technology gap the equipment or
tools used the construction experience of workers or in scheduling and phasing of
construction Table A2 33 - Challenges with sub-contractors for site preparation phase
Q What are the wrong perceptions about modular products among market and public Table A2 34 - Wrong perceptions for modular products
Company What are the wrong perceptions about modular products among market and public
A that their only quality is being cheaper
B
In the USA many people the media and even professional engineers do not understand the capabilities of modular construction Many people continue to confuse this form of construction with HUD on frame products
C With our methods (flat pack) that prefabrication reduces the design options The reverse is the case
Company
If the onsite foundation is constructed by an outside general contractor are there additional challenges at the interface in terms of a technology gap the equipment or tools used the constructionhellip
A we need to educate most local subs on our process and reason for doing things a certain way
B Not that directly affects the factory
C No
D -
E -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
111 | P a g e
Q What strategies are taken among manufacturers to either improve the public
perception of modular construction or to promote its advantages to architects and
potential clients Table A2 35 - Solutions for wrong perceptions
Company
What strategies are taken among manufacturers to either improve the public perception of modular construction or to promote its advantages to architects and potential clients
A Going fast Proving the superior nature of our homes by getting more of them into the world
B
There is some cooperation between builders manufacturers architects and engineers to educate the public The national entity is the Modular Home Builders Association See httpswwwmodularhousingcom
C Nothing specific We advertise our advantages and it is enough
Q Any other challenges and recommended solutions for them that you want to add
please Table A2 36 - Recommendations
Company Responses
A -
B -
C The capital cost of equipment Specialised digital equipment is expensive making it difficult for small and medium companies to enter the market
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Final indicators 69
Weights 73
Data analysis 76
Indicators Values 76
Criteria Values 77
Requirement Values 81
Sustainability Values (Final decision) 83
5 Conclusions 84
Decision making process 84
Conclusions and discussion 84
ECONOMIC ndash TIME discussion 84
ENVIRONMENTAL discussion 84
SAFETY AND SOCIAL dominance by modular methods 85
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES 85
Effective external factors on decision 86
Future studies 86
Decision making study on two real projects with the input data of professional
modular and traditional constructors 86
Technological studies about the production line of a modular off-site plant by factory
and on-site visits 86
A survey about challenges in modular construction and its possible solutions to find
adequate solutions 86
Recommendations 87
Cooperation between industrial players and scientific researchers in offsite
construction 87
Education about industrialization in construction and its alternatives 87
Establishing international and regional adequate codes 87
Synchronizing the contract conditions with modular construction conditions 87
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc 88
Changes in financial strategies and adapting them with off-site construction nature 88
6 References 89
Anexo 1 95
Anexo 2 102
1 Survey Q amp A 102
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study 4
Figure 2 2 - UK productivity status (Office for National Statistics -ONS) 5
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS) 5
Figure 2 4 - Value added comparison among industries (ennovacom) 6
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom) 6
Figure 2 6 - Fragmentations between construction industry players and their various productivity
rates (McKinsey 2019) 7
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom) 8
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom) 9
Figure 2 9 - Digital construction organization (wwwbimcommunitycom) 9
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom) 10
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom) 11
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom) 11
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8
meters (modulartch) 12
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau) 13
Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
14
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom) 15
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom) 16
Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom) 17
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom) 17
Figure 2 20 - Production steps of floor cassette to walls and their attachment together
(wwwhowickltdcom) 18
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom) 19
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom) 19
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom) 20
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom) 20
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom) 21
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-
Malec (wmengcom) 21
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo) 22
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
23
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported
module (wwwsteelconstructioninfo) 24
Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the
lower levels (wwwsteelconstructioninfo) 25
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other
metals (vanguardmodularcom) 26
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma
Beton) 26
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction
report MBI 2019) 28
Figure 2 34 - Overlaps of phases in modular construction project 29
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom) 30
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method
(McKinsey amp Company 2019) 31
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom) 33
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom) 33
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes) 34
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom) 34
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk) 35
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images) 36
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site
(wwwcadoltocom) 37
Figure 2 44 - various layers of a module building unit including insulations
(wwwsteelconstructioninfo) 38
Figure 2 45 - Compartment floor at junction with external wall and compartment wall
(wwwsteelconstructioninfo) 39
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use
inside convention centres arenas and temporary structures Image courtesy of HGA and The Boldt
Company (prismpubcom) 40
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The
Boldt Company 40
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction
(archdailycom) 41
Figure 2 49 -Balance between Initial costs and Economical benefits 42
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects
(casasinhauscom) 46
Figure 2 51 - synchronization between supply chain transportation and on-site assembly 47
Figure 3 1 - Online office forms for survey use 49
Figure 3 2 - Questionnaire development 50
Figure 3 3 - Participants motivations to start a modular company 51
Figure 3 4 - Re-use potential 53
Figure 3 5 - Contribution in Covid19 epidemic 53
Figure 3 6 - Post sale services por future clients 54
Figure 3 7 - effective factors in initial investments for start-up companies 54
Figure 3 8 - Lack of knowledge among designers and engineers 55
Figure 3 9 - challenges of using automation in off-site plants 56
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study
(WAHammad 2019) 61
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and
conventional methods (Akbarnezhad 2019) 61
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020) 62
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017) 62
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad
2017) 63
Figure 4 6 - Architectural section of multi-residential building (Aye 2011) 63
Figure 4 7 - Structural elements used in modules (Aye 2011) 64
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012) 64
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES) 65
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM
alternatives 71
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software 74
Figure 4 12 - Possible forms of the value function 75
Figure 4 13 - Value function for total project cost in MIVES 75
Figure 4 14 - Criteria normalized values 77
Figure 4 15 - Project Schedule 78
Figure 4 16 - Waste generation ratios 78
Figure 4 17 - CO2 Emission normalized values 79
Figure 4 18 - Recyclability and re-use potential of alternatives 79
Figure 4 19 - Embodied energy consumption and saving potential by reuse 80
Figure 4 20 - Safety advantage of modular construction over traditional method 80
Figure 4 21 - Social criteria 81
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values
analysed by MIVES 81
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind 82
Figure 4 24 - Modular dominance in safety and social requirements over conventional option 82
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives 83
Figure A1 1 - Injury risks for workers (Hammad 2019) 96
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
96
Figure A1 3 - Co2 amount (Aye 2011) 97
Figure A1 4 - Total project cost (Balasbaneh 2020) 97
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
97
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter) 98
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020) 98
Figure A1 8 - Co2 emission (Aye 2011) 98
Figure A1 9 - Injury risks for workers (Hammad 2019) 100
Figure A1 10 - Noise level (Hammad 2019) 100
Figure A1 11 - Greenhouse gas emission (Aye 2011) 101
Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo) 23
Table 2 2 - Possible benefits in projects scheduling 32
Table 2 3 - Economic benefits in modular method 35
Table 2 4 - Environmental Benefits 37
Table 2 5 - Health and safety amp Social-Laboral advantages 39
Table 3 1 - Participantrsquos profiles 50
Table 4 1 - Requirement tree with all indicators which considered for decision making process 67
Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed
to be done on them 68
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other
studied 68
Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow) 68
Table 4 5 - Qualitative indicators 69
Table 4 6 - First hand data over literature 69
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow) 70
Table 4 8 - First hand data over literature 70
Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue) 70
Table 4 10 - First hand data over literature 70
Table 4 11 - Final indicators for PCM 72
Table 4 12 - TRC first-hand data over literatures 72
Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow) 72
Table 4 14 - Final Quantitative indicators used for decision making process 72
Table 4 15 - Requirement weights 73
Table 4 16 - Weights of criteria 73
Table 4 17 - Value function for indicators in MIVES 76
Table 4 18 - Indicators normalized values 76
Table 4 19 ndash Indicator normalized values 76
Table 4 20 - Criteria normalized values 77
Table 4 21 - Criteria normalized values 77
Table 4 22 - Requirement normalized values for four indicators 81
Table 4 23 - SI (Sustainability Indexes related to four alternatives) 83
Table A1 1 ndash Cost of project PSM (Hammad 2019) 95
Table A1 2 -Time of project PSM (Hammad 2019) 95
Table A1 3 - Energy utilized during construction (Hammad 2019) 95
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 96
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use
amount (Aye 2011) 99
Table A1 6 6 - Projects cost (Hammad 2019) 99
Table A1 7 - Projects schedule (Hammad 2019 99
Table A1 8 - Energy utilised during construction process (Hammad 2019) 100
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011) 101
Table A2 1 - Professional experience of the company 102
Table A2 2 - Personal experience of participant 102
Table A2 3 - Type of modules 102
Table A2 4 - Type f projects 102
Table A2 5 - Characteristics of production range 103
Table A2 6 - Motivation for doing modular construction 103
Table A2 7 - Panel production conditions 103
Table A2 8 - Level of automation 103
Table A2 9 - Laboral status 104
Table A2 10 - Recycle and Re-use 104
Table A2 11 - Innovative technology integration 104
Table A2 12 - Automation status on waste generation 104
Modular Construction potential advantages and common challenges | Masoud Veiskarami
Table A2 13 - Reduction of waste 105
Table A2 14 - Energy consumption status 105
Table A2 15 - Delivery of projects in COVID-19 pandemic period 105
Table A2 16 - Aid organization project delivery 106
Table A2 17 - Post-sale services to client 106
Table A2 18 - Initial costs 106
Table A2 19 - Effective factors on initial costs 106
Table A2 20 - Re-use effect on budget 106
Table A2 21 - positive factors about modular construction to be chosen 107
Table A2 22 - Use of BIM in projects 107
Table A2 23 - Influence of production line on design 107
Table A2 24 - Lack of knowledge among experts 108
Table A2 25 - Transportation regulation effect on projects 108
Table A2 26 ndash Transportable material choice and its effects 108
Table A2 27 - Challenges of using automation 108
Table A2 28 - Contract condition in modular industry 109
Table A2 29 - Participation status in modular projects 109
Table A2 30 - Role of outside general constructor 109
Table A2 31 - Changes in production line and its effects 110
Table A2 32 - Site preparation status 110
Table A2 33 - Challenges with sub-contractors for site preparation phase 110
Table A2 34 - Wrong perceptions for modular products 110
Table A2 35 - Solutions for wrong perceptions 111
Table A2 36 - Recommendations 111
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
1 | P a g e
1 Introduction
Motivations
Construction industry is suffering for a poor productivity problem during the past 60 years in
comparison with other industries and industrialization in construction was suggested by the
investigators to improving the construction performance by applying production technologies and
design standardized products to be built in off-site plants By searching over the off-site methods
modular construction was found which is benefiting its high sustainability and productivity in
comparison with traditional construction approaches
One of the motivations of these study is to study the advantages of modular construction in
order to demonstrate the superior nature of modular construction over traditional methods to be
presented as a reasonable solution for productivity problem the However there are various of
opinions and argues about the beneficiary of this method so that it was decided to analyse them more
deeply in construction management perspective and even get into contact with the industry for
professional confirmation
Another motivation of this study was to contribute to development of modular construction
and find what is holding it back from developing by discovering the challenges in the modular
construction industry and find possible solutions to help for growth
Orientation of previous studies
During past two decades fewer studies in comparison with other innovative methods have
focused on this subject to analyse this method in economic environmental and functional areas to
discover the benefits and make comparisons with traditional construction methods where possible
McKinsey amp company report on 2019 had general overview on its potential advantages challenges
and its ability to raise the productivity in construction processes while introducing the benefits by
making comparisons in projectrsquos schedule budget and environmental performance among modular
and traditional methods and finally shedding a light on dark side which are the obstacles of growth in
industry and then suggesting possible solutions for improvements In addition there are numbers of
articles focusing on the environmental performance of modular buildings by doing Lifecycle
assessment (LCA) analysis on emissions waste generations and consumption primary resources etc
(Mohammad Kamali and Kasun Hewage et al 2016)
On the other side there are studies that made comparisons between traditional and modular
methods of construction to build a specific project based on BIM models and professional data bases
which led to great results that showed numbers of advantages (AWA Hammad et al 2019) (L Aye
et al 2011) (Ali Tighnavard Balasbaneh at Springer-Verlag 2020)
Gap of knowledge
Taking into account of existent researches there is a gap of knowledge which leads to few
questions that still have remained without answer
bull Confirmation of these benefits that came from scientific researches by professional
players in the industry
bull Do these advantages effect the final decision to choose modular method over
conventional way
bull What are the needs of the market that could be as motivations to use modular
construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
2 | P a g e
bull What are the challenges in the industry in the professional point of view
bull Do the solutions that suggested by researchers can be applied in real projects What
are their professional solutions
Objectives of the study
The importance of this study is to resolve the mentioned questions by accomplishing the
studyrsquos objectives that are separated to be achieved by two methods which are qualitative and
quantitative
Survey among the professionals in the modular industry by Online Form
bull To confirmcorrect the data from literature reviews about benefits of modular
construction
bull Their motivations and reasons to choose modular method
bull What are the constraints and obstacles that they are facing
bull Recommendations and solutions for these problems
Decision-making among three modular methods and conventional option by MIVES
bull To discover the advantages in real study cases by comparisons between four
alternatives
bull To examinate the functionality of every alternative in several criterions
bull How much effective these benefits can be in the final decision based on the
requirements of market and their priorities
Limitations
Several obstacles were seen during the study that effected the methodology and input data
significantly Here are some examples
Lack of existence of references related to the subject
Because of the subjectrsquos novelty or less focus the quantity of references is not enough to
cover all the dimensions of study therefore few estimation hypothesis (that were proved by the
results at the end) and consultants with experts were used instead to provide the necessary
information In addition many of the scientific reports and articles were published few months or
even days before the studyrsquos conclusions so that it was decided to be used immediately to improve
the studyrsquos liability
Non-accessible information from companies and scientific articles
There are innovative companies that because of their privacy policies and protection of
innovation could not provide the necessary data about their projects by request even for academic
uses
On the other side scientific papers in some cases were protected and did not have open
access not even with educational access permissions as requests have been denied by the authors
Obstacles caused by global lockdown during covid-19 pandemic
One of the unpredicted challenges that happened during the study was the virus pandemic
that affected the world negatively and this study was not an exception From on-site project and off-
site factory visits interviews with experts in the industry etc were cancelled Numbers of regions went
to full shutdown including offices factories etc which resulted in reduction of participations in online
survey form as well Therefore it was decided to select five most suitable participants to be analysed
instead of planed massive quantity of results
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 1 Introduction
3 | P a g e
Organization of the thesis
⎯ Chapter two state of the art explaining the productivity problem history types and
phases of modular construction and literature reviews on benefits and challenges
⎯ Chapter three The online survey among modular players in the industry
⎯ Chapter four MIVES multi-criteria decision-making approach
⎯ Chapter five Conclusions and findings
⎯ Chapter six Recommendations
⎯ Chapter seven references
⎯ Anexo A (Input data references)
⎯ Anexo B (Survey QampA) 2
Kewwords Sustainability Modular construction MIVES Productivity rate Prefabrication Lifecycle assessment (LCA)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
4 | P a g e
2 State of the art Productivity problem in construction industry
Status of productivity rate of construction industry among other industries
It has been decades that construction industry is far behind the other industries in terms of
productivity rates Attempts had been done by innovative players in the industry but still the
difference is too enormous which the demands for improvement are needed
Globally construction sector labour-productivity growth averaged 1 percent a year over the
past two decades compared with 28 percent for the total world economy and 36 percent for
manufacturing If construction productivity were to catch up with the total economy the industryrsquos
value added could rise by $16 trillion a year (McKinsey 2019)
It can be said that the building industry is one of the key industries in the general economy
The construction sector typically comprises 8-10 of the Gross Domestic Profit (GDP) of a Western
economy (McGeorge amp Palmer 2002) Therefore only 10 improvement in construction
performance can represent a 25 increase in GDP (McGeorge amp Palmer 2002) Therefore there is
no doubt that improving productivity in the building industry will contribute positively to the general
economy
Figure 2 1 - Productivity status among other industries (wwwfieldwirecom) MGI study
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
5 | P a g e
The UK has a problem with productivity and the construction sector has poorer productivity
growth rates than any other Simply put productivity is the amount of stuff (whether goods or
services) that is produced by a person in an amount of time UK productivity is lower than it was in
2008 and the construction industry has not seen any significant growth in productivity in the last 20
years (Figure 22)
Figure 2 2 - UK productivity status (Office for National Statistics -ONS)
Not all the regions are struggling at the same rate and the reasons which will be discused
furthermore can be the insterest of regulators to support innovations and new solutions which can
improve the productivity in construction industry(Figure 23)
Figure 2 3 - Comparison of construction productivity in regions (EUKLEMS)
The result is that between 70 and 90 of projects exceed the original planned cost and that
the overrun commonly varies between 50 and 100 of budget Construction also suffers from 57
of effort on non-value-added activities compared with 26 within manufacturing (Figure 24)
These productivity rates had experienced severalrises and downs in some periods which is
because of increase of demandas of housing that results a boost in construction industry in order to
provide the needs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
6 | P a g e
Figure 2 4 - Value added comparison among industries (ennovacom)
Reasons of poor productivity
There are numbers of reasons for this poor performance The industry is extensively
regulated very dependent on public-sector demand and highly cyclical Informality and sometimes
corruption distort the market Moreover poor project management and execution insufficient skills
inadequate design processes and underinvestment in skills development RampD and innovation can
affect the productivity indirectly by decreasing the feasibility and value of the activities and add extra
costs on the project
Another key factor that causes a disruption among construction players which reduces the
average productivity rate is the lack of harmony in productivity between the players In other words
The sector divides mainly in two large-scale players involved in heavy construction such as civil and
industrial work and large-scale housing and a large number of firms engaged in fragmented
specialized trades such as mechanical electrical and plumbing work that act as subcontractors or
work on smaller projects like refurbishing single-family housing The first group manages to have 20
to 40 percent higher productivity than the second However even in the more productive heavy
construction sector there are endemic-potentially structural-challenges in meeting cost and schedule
commitments on megaprojects and players routinely subcontract specialized trades (McKinsey amp
Company 2019) (Figure 26)
Figure 2 5 - Poor productivity reason( Leon van Heerden on journeyappscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
7 | P a g e
Figure 2 6 - Fragmentations between construction industry players and their various productivity rates (McKinsey 2019)
Solutions for improvement
Nowadays there are solutions which are being used in construction world such reshaping the
regulation rewiring the contractual framework to reshape industry dynamics rethink design and
engineering processes improve procurement and supply-chain management improve on-site
execution infuse digital technology new materials and advanced automation and reskill the
workforce Each region based on their capabilities potential and Infrastructures would take a decision
which ways can be applied to increase the productivity in construction projects in a short or long
period
bull Redefine regulation Actions include streamlining permitting and approvals processes as
Australia has done reducing informality and corruption and encouraging transparency on cost
and performance as the International Construction Measurement Standards project does Many
governments allocate grants for innovation and training Germanyrsquos Federal Ministry of Transport
and Digital Infrastructure (formerly the Federal Ministry of Transport Building and Urban
Development) for instance supports RampD through studies in building materials Best practice
regulation would include moving toward outcome-based more standardized building codes and
consolidating land to promote scale Examples include Singaporersquos move to allow cross-laminated
timber (CLT) for high-rise structures and Japanrsquos promotion of scale through land pooling
bull Re-arrange the contractual framework Establishing a ldquosingle source of truthrdquo on projects for
monitoring progress early potentially supported by collaborative technology helps to minimize
misalignments and enable joint corrective action The data already exist to fundamentally
improve the accuracy of cost and schedule estimates Where players continue to use traditional
contracts they should introduce incentives that significantly improve performance and alignment
not at a trade or package level but at the project-outcome level To move toward best practices
appropriate alternative contracting models such as integrated project delivery (IPD) help build
long-term collaborative relationships Relational contracts will need to become more prevalent
than transactional contracts Sufficient investments in up-front planning incorporating all partiesrsquo
input have been shown to raise productivity substantially Smart Contracts are another example
of these solutions which during recent years is being identified by the major players A smart
contract is a computer program or a transaction protocol respectively which is intended to
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
8 | P a g e
automatically execute control or document respectively legally relevant events and actions
according to the terms of a contract of an agreement or of a negotiation The objectives of smart
contracts are the reduction of need in trusted intermediators arbitrations and enforcement costs
fraud losses as well as the reduction of malicious and accidental exceptions (Tapscott Don
Tapscott Alex amp Savelyev Alexander 2016)
Figure 2 7 - Block chain and smart contracts functionality in construction (enstoacom)
bull Off-site production shift The biggest impact on productivity would come from moving toward
thinking about construction as a production system where possible encouraging off-site
manufacture minimizing on-site construction through the extensive use of pre-cast
technology assembling panels in factories and then finishing units onsite
bull Improve on-site execution There are four key approaches that are well known in the industry
but have not been universally adopted First is the introduction of a rigorous planning process
the Last Plannerreg System (LPS) is a useful tool to ensure that key activities are achieved on
time and on budget The use of integrated planning tools on a large-scale oil and gas project
for instance achieved a 70 percent increase in the projectrsquos productivity Second is reshaping
the relationship and interactions between owners and contractors and key performance
indicators (KPIs) being agreed on and used at regular performance meetings at which on-site
issues are resolved Complementing commonly used KPIs with additional forward-looking plan
conformance metrics to identify and subsequently reduce variance is critical Third is
improving the mobilization for new projects by ensuring that all pre-work (for instance
obtaining approvals and developing project milestones) has been completed prior to starting
onsite Finally there is a need for careful planning and coordination of different disciplines
on-site along with the application of lean principles to reduce waste and variability On-site
productivity can be increased by as much as 50 percent by implementing a cloud-based
control tower that rapidly assembles accurate data in near real time that is both backward-
looking and predictive (for example using plan conformance and other variability and
inventory metrics)
bull Introduce digital technology advanced automation Companies can start by making 3D
building information modelling (BIM) universal within the company alongside use of digital
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
9 | P a g e
collaboration tools drones and unmanned aerial vehicles for scanning monitoring and
mapping They can put themselves at the cutting edge by using platforms such as 5D BIM to
establish transparency in design costing and progress visualization (Figure 28)
Figure 2 8 - BIM 5D model for cost and time estimation (wwwblazethreadcom)
Advanced analytics enabled by the Internet of Things to improve on-site monitoring of
materials labour and equipment productivity and digital collaboration and mobility tools (such as
construction management apps loaded on mobile devices) to better track progress and collaborate in
real time (Figure 29)
Figure 2 9 - Digital construction organization (wwwbimcommunitycom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
10 | P a g e
Advanced automated equipment and tools such as bricklaying and tiling robots can accelerate
on-site execution The field of digital fabrication (dfab) is quite broad and has many applications Dfab
techniques are based on the combination of computational design methods and automated
construction processes which are typically categorized as subtractive formative or additive
(Kolarevic 2003) The use of subtractive and formative digital fabrication is becoming mainstream in
the prefabrication (off-site) of building parts (eg by using laser cutting CNC milling etc)
In recent years additive fabrication processes especially 3D printing have experienced a
rapid development in many industries As interest in additive fabrication grows research into large-
scale processes begins to reveal potential applications in construction (Labonnote et al 2016)
Existing additive dfab technologies can be classified in two big clusters on-site and off-site
construction technologies On the one hand on-site digital fabrication aims to bring additive
fabrication processes on construction sites
Sousa et al (2016) classified on-site technologies in three main categories large scale robotic
structures mobile robotic arms and flying robotic vehicles A well-known example from first category
is Contour Crafting a robotic structure for 3D printing large-scale construction developed at the
University of Southern California (Khoshnevis 2004)
Figure 2 10 - Professor Behrokh Khoshnevis the inventor of contour crafting (inhabitatcom)
bull Reskill the workforce Change in the construction sector cannot be achieved without
investment in retooling a workforce that is aging and changing its makeup through migration
Construction firms and workers need to continuously reskill and train to use the latest
equipment and digital tools In the mix should be apprenticeship programs such as the one
run by Siemens in the United Kingdom training frontline workers in core skills that are
currently underdeveloped and increasing stability in the workforce by breaking seasonality
and cyclicality
Brief on modular construction
History of modular construction
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
11 | P a g e
bull 1800s
In 1830 he first documented prefabricated home was created by London carpenter John
Manning for his son who was moving from England to Australia Manning built a prefabricated house
in pieces then shipped it to the Land Down Under for easy assembly In 1840 Modular construction
made its way to the United States in response to the housing needs of the California Gold Rush The
Crystal Palace was built for Britains Great Exhibition and remains one of the most famous examples
of early modular construction in 1851 Designed in less than two weeks it utilized light and
inexpensive materials such as iron wood and glass it was constructed in only a few months
Afterward the palace was dismantled moved and rebuilt at another location
Figure 2 11 - Crystal palace located in London was built in 1851 (bloginoxstylecom)
bull 1900s
Augustine Taylor a builder in Chicago devised the balloon-frame method (Figure 212)
enabling walls to be built offsite then transported to the intended construction site for speedy
assembly The rise of catalogue houses happened Between 1908 and 1940 when Sears Roebuck and
Co sold more than 500000 prefab homes through its catalogue straight to consumers At the time
these houses cost less than two-thirds of conventionally built homes and many still exist throughout
the United States
Figure 2 12 - Balloon-frame walls by Augustine Taylor (likemyplacewordpresscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull WWII Housing Boom
Prefab structures continued into World War Two to meet the growing demand for mass
accommodations for military personnel So-called Quonset Huts or Nissen Huts in the UK
comprised of corrugated steel were introduced for domestic military and institutional uses
When soldiers began returning home in the United States there was a need for rapid
construction for new homes to accommodate these expanding families Once again modular
construction serviced those needs because of its efficiency reduced costs and quick construction
Today many of those units are still in use
bull Prefab in Post-war Europe
The situation in Europe was more difficult although millions of people had no place to live on
the Old Continent due to the destruction of the Second World War people were unwilling to accept
prefabricated construction In Germany which had not only lost 25 percent of its entire housing stock
to bombing but also had to integrate 12 million refugees from former German territories in Eastern
Europe one form of prefabricated housing was used extensively the Nissen Hut (similar to the
Quonset hut) An attempt was also made in post-war France to combat housing shortages with the
help of prefabricated houses In 1944 Jean Prouveacute was already commissioned by the Ministry of
Reconstruction and Urban Planning to build 800 houses as emergency shelters that could be easily
disassembled However only 400 of these Maisons agraveportique which were equipped with an axial
steel frame were ever erected Prouveacutes Alba houses developed for the Abbey Pierres homeless
organization in 1956 were also not a success (Peter Goumlssel Arnt Cobbers Oliver Jahn 2012
architectureweekcom)
Figure 2 13 - Jean Prouveacute built various modular buildings with steel porticos with a width of 8 meters (modulartch)
bull The Pre-fabulous 60s
The 1960s were a period of social transition in which attitudes towards prefabricated housing
also changed During this era which was marked by space travel the moon landing and even childrens
books that predicted weekend trips to distant galaxies prefabricated construction was discovered both
as a form of artistic expression and as a technical means of creating houses to provide a basis for new
lifestyles which seemed to be imminent in a society characterized by an extremely optimistic view of
progress
These approaches supported the idea of creating megastructures out of residential capsules
the architect Moshe Safdie who was only 24 at the time presented his megastructure Habitat 67 at
the Expo 67 in Montreal 158 housing units consisting of 354 concrete modules assembled as a
conglomerate
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The British architectural group Archigram developed building structures made of residential
capsules as an architectural Utopia which could be expanded at will and joined to form entire cities
Figure 2 14 - Moshe Safdies Habitat 67 multi-capsule project (coastlineminigaragecomau)
bull Eco-conscious 70s
In 1972 the Japanese architect Kisho Kurokawa built the Nakagin Capsule Tower in Tokyo
housing cells were layered around a prefabricated concrete core to form a fourteen-story residential
tower(Figure 215) The idea of residential capsule megastructures was repeatedly revived as in Zvi
Heckers Ramot housing development in Jerusalem in 1974
The ecology movement of the 1970s brought an end to this euphoria regarding technological
progress and futuristic architectural dreams Now highly modern building materials that did not seem
to be in harmony with a return to nature such as plastic or aluminium fell into disrepute A new
perspective of view replaced as a priority to choose the material types which have the minimum
relation with non-renewable resources
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 15 - Nakagin Capsule Tower in Tokyo another example of capsule concept (archdailycom)
bull 90s
This was further exacerbated by the fact that prefabricated elements had often been used to
build high-density housing which was now generally viewed negatively Hence prefabricated building
now came to be associated with the aesthetic and social failure of deindividualized megalomaniac
prefabricated slab housing blocks clustered on the periphery of large cities Thus the acceptance of
the prefabricated house in large parts of Europe remained low up until the 1990s
Prefabricated construction only gradually began to again emancipate itself from a homespun
cheap mass-produced image during the 1990s This is mainly due to the use of computer-operated
programs in the design and production processes The prefabricated housing industry now stands at
a juncture reminiscent of the dynamism of the 1920s and 1930s
bull Modern days
For many years now companies like Muji in Japan or BoKlok in Scandinavia and more recently
also in Poland and England have been supplying prefabricated houses in large numbers In Sweden
alone with only nine million inhabitants 14000 units are sold every year Muji offers models designed
by Kengo Kuma and Kazuhiko Namba that are as simple as they are elegant and far more interesting
than the building-kit houses offered by the multinational concerns Mitsubishi Toyota and Panasonic
(deluxemodularcom 2019)
Countries around the world have enlisted prefab and modular construction methods for
decades For example an estimate of all detached homes that are prefabricated in each country
shows a potential for growth off 84 in Sweden 5 in the United States 9 in Germany 20 in the
Netherlands and 28 in Japan
Today prefabrication and modularization are utilized in the construction of hotels apartment
buildings offices hospitals and schools in every major US city Here is a rundown of the percentage
per industry of prefabricated structures that use some form of modular construction
(deluxemodularcom 2019)
bull 49 of healthcare facilities
bull 42 of college buildings and dorms
bull And 42 of manufacturing buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Types of modular product
Module architectural types
The products can be categorized by its functions dimensions material or type of its operation
etc Here they will be introduced by their general characteristics
bull Bathroom pods
Bathroom pods are commonly used in the construction of most hotels and apartment
buildings these days and becoming used more for residential housing The main drivers for choosing
a modular pod method are
o The cost savings that can be made by building repeated designs in a factory
environment
o Higher quality finish
o Rapid installation
o No trades on site
Figure 2 16 - Bathroom pods built offsite full equipped (wwwhowickltdcom)
Pod Construction Process can be various but the most common steps can be as below
(httpswwwhowickltdcom)
Once the bathroom specification has been finalized and the design completed the
machine files are issued and the framing can be produced
The frames are rolled out of the machine ready for assembly
The panels are assembled
The panels are then fitted with the internal boarding and finished with tiles or a
waterproof lining
The walls floor and roof are joined to create the room structure and the joints sealed
The fixtures and fittings can then be installed including
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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o Bath or shower
o Toilets
o Basins
o Lights
o Mirrors
o Cabinets
The plumbing and electrical components are connected
The pods are then subjected to an electrical test and a pressure test to ensure there
are no leaks (Figure 217)
The pods are then sealed to prevent access ready for transportation
Once on site the pods are slid into position and connected to the power and water services
This process greatly reduces the build time as there are no requirements for trades on the site As the
pods are sealed until the building is completed there are reduced chances of them being damaged
during the building construction phase
Figure 2 17 - Plumbing testing off-site before transportation to the location (wwwhowickltdcom)
bull Kitchen pods
These pods are less common but are also becoming more frequently used All the appliances
and electrics can be fitted in the factory removing the need for work on site Kitchen pods are ideal
for renovating older or industrial buildings as all the electrical services for the building can be
integrated into the pod From student accommodation to residential flats modular kitchen pods are
suitable for a variety of different sectors and uses and because they are designed bespoke to each
clientrsquos exact specifications they can be anything from a fully fitted kitchen to a small kitchenette
Each modular unit is completely customisable from the worktops to the splashbacks and integrated
white goods
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 18 - Production line of kitchen modules (wwwhowickltdcom)
bull Volumetric and modular rooms
Volumetric and modular rooms are becoming widely used for buildings that have a repetitive
nature Common structures include
bull Hotels
bull Apartments
bull Student accommodation
bull Schools
bull Hospitals
Figure 2 19 - Student accommodation made by modular rooms (wwwhowickltdcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The benefits of being able to manufacture the complete unit in the factory (including the
bathrooms and fitting of furniture) are
o No weather delays
o Superior finish quality
o All the electrical and plumbing works are done in a controlled atmosphere
o The rooms are sealed before moving to site restricting unauthorized access
Modular rooms production process can be explained as below
Once the building design has been completed and the individual modules specified the
framing components can be made on a just in time basis for site delivery
A typical assembly process would consist of
The floor cassette is rolled and the flooring boards are attached along with the
required insulation and services
The wall and ceiling frames are assembled
The internal lining is fitted and painted
The wall frames are then attached to the floor cassette (Figure 220)
Figure 2 20 - Production steps of floor cassette to walls and their attachment together (wwwhowickltdcom)
The ceiling frames are then fitted
The bathroom can then be fitted and plumbed as well as the electrical fittings and
wiring
The wall and ceiling insulation is added to the frame
The fit-out can then be completed to the desired specification
A hotel module for example would feature carpets bed bedside furniture desk
wardrobe TV system air-conditioning (either vents from main system or stand-alone
unit) bathroom fittings and fixtures
Once completed the electrics are checked and the plumbing is pressure tested
A protective cover is then added for transport and the unit is delivered to site
On-site the units are craned into position and joined
The services are connected
The building is then roofed and clad to the required specification In some cases the cladding
can be fitted during the module assembly further reducing the on-site work
bull Modular Trailers
Outside of modular homes modular trailers are probably the type of modular building that
people are most familiar with These buildings have a lot of applications and are often used as a
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
19 | P a g e
temporary space solution These trailers can be relocated for several times and are well-equipped as
well Temporary pre-semester school classes and temporary offices can be two examples of these
trailers uses
Figure 2 21 - Modular trailers for temporary uses (wwwpanelbuiltcom)
Figure 2 22 - 68 X 56 Portable modular classrooms (wwwwillscotcom)
bull Containers
When looking at modular containers they are structures that are typically used to contain a
shiprsquos cargo When Shipping containers were originally created they were designed with modularity
in mind They were required to withstand all kinds of abuse as they journey through some of the
worldrsquos harshest climates From salt water to freezing temperatures a shipping container is meant to
handle the worst of the worst while protecting some of the worldrsquos most precious cargo Comprised
of Corten steel it is in a shipping containers DNA to protect itself from any corrosion or rust and when
they fall off the ship they can take up to a week to sink With more boxes being imported than
exported we have an opportunity to reuse something that is desperately looking for a new home
There has been a shift recently where after these buildings serve their purpose as shipping containers
they are reused fitted with windows doors HVAC units etc And made into an office environment
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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The biggest benefit of these containers is they are cheap very portable and easy to install on site
However since most of the time these buildings are retrofitted and remodelled into modular
buildings they usually do not have a lot of flexibility in layout or their dimensions
Figure 2 23 - Common Ground by Urbantainer (wwwframewebcom)
Shipping containers act as the exoskeleton of each module The original structure will frame
the HVAC wiring lighting plumbing appliances and wall finish materials Because containers were
built to be durable and mobile they can be transported by train tractor-trailer boat or in some cases
a powerful pickup truck Forklift pockets and corner castings allow the containers to be moved smaller
distances by crane and forklift Shipping containers empower you to move your modular structures
without sacrificing the structural integrity or damaging the modulersquos contents
Figure 2 24 - Modular accommodations made from shipping containers (wwwpanelbuiltcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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bull Office Complexes
Office complexes will take several office modules and combine them to assemble a much
larger fully functioning office building Just like all modular construction these modules are
fabricated in a manufacturing environment except when these projects reach the job site they
function more similarly to a full-fledged construction site Generally the module will need a crane to
lift the section from the ground and place it in the correct spot to assemble the building Next the
workers will go through that module and do all things necessary to attach and hook up the piece
Then the next piece is put in place and these steps are repeated and again until the building is
finished
Figure 2 25 - An example of office complexes (wwwpanelbuiltcom)
bull Modular enclosures
For instance one of the major electric utilities in the Northeast using Modular Construction is
Wunderlich Malec Integrated Control Enclosures since 2001 A standard 16times50times11-foot enclosure
with twenty (20) protective relay and control cabinets marshalling cabinets HVAC fire and security
completely installed wired and tested at the factory prior to shipment
Figure 2 26 - A Northeast utility used Power Distribution Centers (PDC) delivered by Wunderlich-Malec (wmengcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
22 | P a g e
Module structure types
Modular structure types can be categorized by their materials or structural formation
o Steel Modules
bull 4-sided modules
In this form of construction modules are manufactured with four closed sides to create
cellular type spaces designed to transfer the combined vertical load of the modules above and in-
plane loads (due to wind action) through their longitudinal walls The cellular space provided is limited
by the transportation and installation requirements Depending on location and exposure to wind
action the height of buildings in fully modular construction is in the range of 6 to 10 storeys Modules
are manufactured from a series of 2D panels beginning with the floor cassette to which the four wall
panels and ceiling panel are attached generally by screws The walls transfer vertical loads and
therefore the longitudinal walls of the upper module are designed to sit on the walls of the module
below
Figure 2 27 - Details of 4 sided modules showing recessed corners with additional angle sections
(wwwsteelconstructioninfo)
It consists of a modular structure of high strength galvanized steel which is also used as the
basis for building closure Steel physical properties make it one of the most versatile materials for
construction since it is
ELASTIC Steel does not break as it has a great strength and elasticity It is easily workable and it has
a great advantage over traditional construction
RECYCLABLE Steel is 100 recyclable
DURABLE With zinc application it can become galvanized steel which has extraordinary durability
properties
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Table 2 1 - 4 sided dimensional details (wwwsteelconstructioninfo)
bull Partially open-sided modules
4 sided modules can be designed with partially open sides by the introduction of corner and
intermediate posts and by using a stiff continuous edge beam in the floor cassette The maximum
width of opening is limited by the bending resistance and stiffness of the edge member in the floor
cassette Additional intermediate posts are usually square hollow sections (SHS) so that they can fit
within the wall width
Figure 2 28 - Layout of apartments using partially open sided modules alternate modules are shaded
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
24 | P a g e
bull Open sided (corner-supported) modules
Modules may be designed to provide fully open sides by transfer of loads through the
longitudinal edge beams to the corner posts The framework of the module is often in the form of hot
rolled steel members such as Square Hollow Section (SHS) columns and Parallel Flange Channel (PFC)
edge beams that are bolted together
Figure 2 29 - corner supported module end view amp Longitudinal edge beams of a corner supported module
(wwwsteelconstructioninfo)
bull Modules supported by a primary structure
Modular units may be designed to be supported by a primary structure at a podium or
platform level In this case the supporting columns are positioned at a multiple of the width of the
modules (normally 2 or 3 modules) The beams are designed to support the combined loads from the
modules above (normally a maximum of 46 storeys) The supporting structure is designed
conventionally as a steel framework with beams and columns that align with multiples of the module
width and provides open plan space at ground floor and below ground levels This form of construction
is very suitable for mixed retail commercial and residential developments especially for residential
units above commercial areas or car parking etc particularly in urban projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Figure 2 30 - Modules supported by long spanning cellular beams to create open plan space at the lower levels
(wwwsteelconstructioninfo)
o Wood structure
Back in the days of the very first modular buildings wood was the modular construction
material of choice and nowadays it overwhelmingly remains the most used for these projects due
to its abundance and cheaper initial costs Wood-framed modular buildings however have several
notable limitations that might give a property developer pause and may even prove more costly in the
long-term repairs
Wood often lacks the strength necessary to support large building projects especially those
of multiple stories Due to this weakness wood-framed buildings are typically no taller than a few
stories a considerable limitation for someone looking to build a hotel or apartment building as
examples
Wood is flammable and vulnerable to fire which could severely damage the structural
integrity of the building requiring replacement or even worse leading to a total collapse
Wood tends to warp over time resulting in a lower quality building in the years after
completion Combined with its susceptibility to pests and mold selecting wood for a modular
structure may prove to be the more expensive choice in the long term considering repair costsmdasheven
despite initial savings
Wood is among the most wasted materials used in modern construction On average 20 of
construction lumber typically ends up in landfills leaving a larger environmental footprint than other
alternatives (httpswwwdeluxemodularcom)
Considering all those negative points mentioned earlier there are numbers of regions that
still are oriented to wooden structures as this type of housing is part of culture of the society because
of traditional architecture etc therefore typical clients prefer to build the type of accommodation
that they trusted for many years as it became the main demand of market Accessible local resources
availability of necessary knowledge for construction and compatibility of labour forces with this
method are other reasons to be chosen over the other alternatives
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
26 | P a g e
Figure 2 31 - Wooden modular structure which as an insulator wood is superior to steel or other metals
(vanguardmodularcom)
o Concrete modules
Precast concrete is a well-established and efficient manufacturing industry and products
range from hollow-core slabs to beams and columns in structural frames Concrete modules can be
manufactured in two ways either from precast 2D wall floor and ceiling panels or as 3D modular
units which are generally cast with an open base Concrete modules are often used in high-security
applications as they are extremely resistant to damage
Figure 2 32 - Mounting of the first precast units for the Zaanstad penitentiary building (Haitsma Beton)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
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Types of modular buildings based on operation period
bull Relocatable Buildings (RB)
Relocatable modular buildings are designed to be reused or repurposed multiple times and
transported to different sites Relocatable Building as defined in the 2015 International Existing
Building Code a partially or completely assembled building constructed and designed to be reused
multiple times and transported to different building sites
bull Permanent Modular Construction (PMC)
PMC is an innovative sustainable construction delivery method utilizing offsite lean
manufacturing techniques to prefabricate single or multi-story whole building solutions in deliverable
module sections PMC buildings are manufactured in a safe controlled setting and can be constructed
of wood steel or concrete PMC modules can be integrated into site-built projects or stand alone as
a turnkey solution and can be delivered with MEP fixtures and interior finishes in less time with less
waste and higher quality control compared to projects utilizing only traditional site construction
Common uses of modular buildings in the market
o Education
Relocatable buildings have become a critical factor in managing student demographics and
increasing enrolments Relocatable classrooms are also ideal for swing space during new construction
or renovation Convenient flexible cost-effective temporary buildings can be delivered and
operational in as little as 24-hours These classrooms are measured for quality and code compliance
by state or third-party agencies through routine and random inspections testing and certification
services Customers may choose single classrooms or arrange multiple buildings in clusters to create
a campus feel MBI members supply steps decks ramps and even furniture Members also offer
lease purchase and lease-to-purchase financing for a variety of public and private school needs
These classrooms are sometimes referred to as temporary portable or mobile classrooms
o Construction-Site
Relocatable buildings have their roots in construction site trailers where speed temporary
space and relocate-ability are important Used as standard field offices construction site and in-plant
buildings are available for immediate delivery Standard construction is wood but steel units are
available to meet non-combustible requirements In-plant buildings are available as single- or two-
story units for industrial environments with noise reducing insulation and are typically moveable by
forklift and include electrical and communications wiring heating air conditioning and even
plumbing
o Healthcare
Relocatable buildings for healthcare applications are designed and constructed to
uncompromising standards of quality A customerrsquos new clinic hospital extension laboratory
diagnostic centre MRI unit dentist office or other medical facility can be open for business and
serving communities in as little as a few days Is your interest in serving patients as quickly as possible
in the safest and aesthetically pleasing environments available These facilities offer quick quiet safe
and clean buildings with an unlimited choice of interior deacutecor and furniture and equipment leasing
o General Administrative and Sales Office
When production demands increase relocatable buildings can temporarily enlarge a current
facility without permanent alterations to the site Because the space is not permanent many
companies are able to expand without the budget approval process necessary for traditional capital
expenses Relocatable offices can be single- and multi-story buildings configured to include
independent offices conference rooms and large open spaces for cubicles or other partition systems
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
28 | P a g e
Large and small businesses as well as local and state governments are typical users of relocatable
office space
o CommercialRetail
Earlier occupancy means quicker return on investment For retail occupancies this can mean
significant cash flow advantages Standard floorplans are available for immediate delivery while
custom buildings are built to specifications in weeks not months Unique to the modular process is
concurrent construction site-work occurs while buildings are being put together in a quality-
controlled factory Typical retail applications include new home sales centers banks golf pro shops
automobile fleet ownerships college bookstores and concession stands If a clientrsquos emerging
business needs are short-term temporary space will accommodate their financial situation space
requirements and deadlines
o Security
Relocatable buildings can be custom built for a variety of access and control situations Toll
booths tickets sales offices guard stands and weigh stations are common applications One and two-
story wood and steel buildings have straight walls or walls that are tilted to improve views and reduce
glare
o EmergencyDisaster Relief
There is simply no other means of providing fast transitional shelter and basic community
needs following natural disasters than relocatable buildings Relocatable buildings can be quickly and
efficiently deployed for emergency shelter medical and educational needs or to accommodate relief
workers
Figure 2 33 - Contribution of different use cases in the US market (Permanent Modular Construction report MBI 2019)
Construction phases
Modular construction is the process of manufacturing multiple building sections in a facility
for assembly at a remote building site The building sections called modules will fit together once
assembled on site with plumbing HVAC and electrical connections running throughout One of the
great advantages in the modular construction process is that many of the processes happen at the
same time which can cut the construction time in half There are six common steps to complete a
modular project Design amp Engineering Permits amp Approvals Site Development Plant Fabrication
Transportation and Installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
29 | P a g e
Figure 2 34 - Overlaps of phases in modular construction project
o Step 1 Design
The design phase of the modular building process creates a description of the building usually
represented by detailed plans and specifications A thorough customer consultation with a Palomar
project manager gathers the information required to develop the building plan Once this information
has been gathered the design team will produce the ideal modular building design to fit the customerrsquos
needs
o Step 2 Engineering
Each building design goes through the engineering department for an engineering review Like
site-built structures modular buildings are subject to a series of national state and local building
codes that ensure the building meets a set of standards for safety and performance State level
building codes can be superseded or augmented by local building code requirements and then must
confirm the design proposal meets all applicable building codes
o Step 3 Permits amp Approvals
A construction permit or building permit is a permit required in most jurisdictions for new
construction or major renovations Typical construction permits required can include
Site plan
Building permit
Mechanical permit
Plumbing permit
Concrete permit
Encroachment permit
Sign permit
Flood district development permit
The building owner is ultimately responsible for securing building permits for work on their
property In practice most building owners appoint the general contractor as an authorized
representative so the contractor can obtain the required permits The building owner is advised to
confirm that the general contractor has secured the proper building permits for their project Failure
to obtain the proper permits can result in significant fines penalties and even demolition of
unauthorized construction
o Step 4 Site Development
One of the advantages inherent in modular construction is that the site development and
building foundation are prepared while the modules are being fabricated at the manufacturing facility
and transported to the job site The site development and building construction processes happen
Permits
Design amp Engineering
Site Development
Plant Fabrication
TransportationOn-site installation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
30 | P a g e
concurrently instead of sequentially like site-built construction Projects are developed on a variety of
geographic settings typical site development includes
Surveying
Demolition
Excavation
Grading
Site drainage
Foundation construction
Utility installation
There are two primary modular building foundation classifications on-grade and raised or full
foundation An on-grade foundation is generally for permanent installations and is more expensive A
full foundation can be used for temporary or permanent structures it is less expensive to install and
it is more cost effective to relocate the building later while causing minimal site disturbance
Figure 2 35 - Pre-cast blocks are often referred to as ldquocinderrdquo blocks (wwwtriumphmodularcom)
bull Step 5 Plant Fabrication
There are two scenarios for steel modular constructors There are few numbers of off-site
plant which built their own steel frames inside the plant because of high initial budget and it is
common that it would be cheaper to order the frames from another supplier and transfer to the
factory to assembly with other parts The steel frame is then loaded on the main factory production
line where the sub-floor is insulated and floor decking is assembled atop the steel frame As the
module moves down the production line framed wall sections are fabricated insulated and hoisted
in place The truss roof assembly is built in components at ground level before it is hoisted into place
The module proceeds down the line where mechanical electrical and plumbing services are installed
while the last of the insulation goes into place Interior finishes like drywall painting and flooring are
applied while doors and windows are installed
On the last stop of the production line the exterior finish and trim are applied before the
module is prepared for transportation
During construction at the manufacturing facility a third-party inspection agency is present to
ensure the modules are built in compliance with building code
bull Step 6 Transportation
The fabricated modules are shipped over the road by carriers that specialize in modular
building transportation In most US jurisdictions building shipping limitations are 16rsquo in width and
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
31 | P a g e
between 70rsquo amp 90rsquo in length per module Permissible Maximum Dimensions of Lorries in Europe and
UK for Lorry or Trailer are 4m in height 255m in width and 12m in length (International
Transportation forum)
bull Step 7 Installation
A general contractor often one specializing in modular construction will install the modules
complete any on site finish out and make the final utility connections
The choice of building foundation determines how the building will be installed Permanent
semi-permanent and on grade foundations will require the modules to be set with a crane Raised
foundations typically used for temporary buildings allow the modules to be set in place through
simple mechanical methods
With the modules in place final finish out of the interior and exterior proceeds Finish out can
include electrical and mechanical system connection between modules stairs wheelchair ramps
skirting exterior siding trim and utility connections
Literature review on possible advantages
Modular construction comes with advantages which motivates investors and innovative
constructors to apply this method on their future projects Here these benefits are being classified in
various sections such as schedule economic environmental health and safety and social-laboral
advantages
Scheduling benefits
While on-site constructors are complaining about the slow progression of construction
activities and delays on project deliveries the struggle is still to be continued to find new methods to
improve productivity and progression speed while maintaining the quality at a reasonable level
whether if its achievable or not On the other side modular construction because of numbers of
reasons is making a significant boost in term of time management in many phases As it can be seen
in figure 236 McKinsey amp Company report explains that approximately between 20 - 50
scheduling improvement can be achieved in comparison with traditional on-site construction
Figure 2 36 - Possible time saving in modular approach in comparison with traditional method (McKinsey amp Company
2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
32 | P a g e
To be more specific literature reviews identified numbers of benefits in most of the
constructive activities from design to on-site installation As the table 22 illustrates off-site
manufacturing brings most of the time saving to the project by better coordination precise quality
management and not being affected by the on-site bad conditions Table 2 2 - Possible benefits in projects scheduling
In addition design can the ability to be applied in multiple projects instead of just one which
accelerates the project schedule significantly Various overlaps in modular construction can save lots
of time in projects such as site preparations off-site manufacturing and on-site installation with each
other
The acceleration in design process which would be ideal for schedule-critical projects (for
instance emergency accommodation for people who are affected by natural causes) also Long-lead
items can be stocked Fabrication can start and finish earlier in this case In the real state point of view
in the design phase there is one huge benefit which will be so handy when nearly ldquoshovel-readyrdquo
design documentation is needed for clients and site selectors (wwwmcminnvillebusinesscom)
The simplicity precision and clarity of the design plans in modular projects can increase the
possibility of using advanced software such as BIM which reduce the period time of designing phase
significantly With the increasing the possibility of integration of BIM in construction project
incorporating modular building technologies into project becomes more developed and
manufacturing and construction process could be streamlined (Na Lu and Thomas Korman 2010)
About 90 percent of the build activity takes place indoors which means the building process
is nearly guaranteed to stay on schedule That predictability and reliability enable you to count on
timely project completion If a skilled modular crew only spends half the time building your structure
than a site-built crew would your labour cost also gets cut in half
Because of stability of production location there are numbers of advanced technologies
which are being used in other industries production lines that can be used in these off-site facilities in
order to improve the productivity and reduce the timeline of the activities
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
33 | P a g e
Figure 2 37 - BIM 3D model of a modular project (wwwbdcnetworkcom)
The nature and outdoor construction have always mutual effects on each other mostly in a
disfavour way Site conditions often cause negative impacts on the activities which lead delays quality
insurances or stop them because of safety matters In result the project schedule can be changed and
most of the times unpredictive delays will take place in the timelines In addition there are sites which
the possibility of on-site construction for most of the year is almost zero percent or if exists would be
limited because of life risks for workforce A reasonable solution for these cases is off-site construction
which in most of them reduce the nature effects Thus factory-based production can make a
revolutionary impact on the project scheduling In modular method 60-90 of the construction work
is completed in a closed factory environment and this mitigates the impact of unfavourable weather
(FLORI MURESAN on ny-engineerscom)
Figure 2 38 - Modular project in a hard weather condition (wwwautodeskcom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
34 | P a g e
Machinery equipment can take place in mentioned phase instead of human labour which can
boost the productivity quality as well as the time reduction Robotic assembly is one the efficient
examples of this technology One of the very first EU projects carried out in the Robotics Lab
(httproboticslabuc3mes) located at the Carlos III University named FutureHome-IF7 project The
done research was focused in the robotization and industrialisation of the final stage of the
construction process by mean of modular construction (Martinez 2008)
Figure 2 39 - Automatic modular buildings assembly (roboticslabuc3mes)
Economic benefits
Economic advantages can always attract investors to develop innovations Since in a project
time and cost have a direct and mutual relation with each other most of the benefits which were
mentioned earlier in the schedule section can also make positive impact in projectrsquos economy In
some cases these benefits equal to the initial costs which will be discussed later in challenges As it
was mentioned earlier the design plans can be repeated multiple times in projects because of
similarity of requirements that can save design costs in future budgets
Modular building because of their standardization and classification in design phase can be
more compatible with advanced such as BIM (building information modelling) BIM technology in its
5D phase does cost estimating material quantifications and pricing to be automatically generated
and modified while changes are applied for each building module (Na Lu and Thomas Korman 2010)
Figure 2 40 - In Bathroom Pods Modular Construction by jfield (wwwsurepodscom)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
35 | P a g e
Foundations do not have complexity in modular buildings because of weight of the modules
which have to be manufactured lightly in order to be transported simpler to the location
Figure 2 41 - Easy PAD foundation system (wwweasypadscouk)
Also because of the high quality and precise off-site execution there are fewer reworks in
modular products which can save costs in projects Off-site manufacturing provides more economic
benefits such as reduction of salary wages due to a smaller number of workers and more specialized
ones and adding values to each hour of work by increasing productivity to the activities
Moreover massive orders of Materials to the supplier can bring more quality to the material
multiple discounts on each offer and add more stability in prices of material in instable markets Table 2 3 - Economic benefits in modular method
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
36 | P a g e
Environmental Benefits
A highlight among the modular constructionrsquos benefits is in the environmental point of view
Since the modular buildings are friendly with environment many clients are willing to change their
method to this ecological approach in order to make their projects more sustainable and promote
their product in the market as an innovative constructor in the industry such as ldquoGrupo Consentinordquo
which not only builds modules that are available to use solar panels as energy supplier but recycle
many structural and non-structural elements and reuse them in another projects Waste management
can be applied simply in modular construction by reduction in waste during off-site production recycle
and reuses in elements in several projects use of automation can secure waste reduction at a high
rate It has been proven that modular construction can reduce waste by up to 90 thanks to off-site
construction (JAHNAVI SAJIP ny-engineerscom)
Agostinho Mendonccedila in 2018 did a research about reuse in construction industry which
shows a great improvement in terms of sustainability During 2022 FIFA World Cup in Qatar football
fans will have the opportunity to enjoy the stunning views of Doharsquos skyscrapers and be marvelled at
the unique Ras Abu Abod Stadium Its design concept results in a good cost-efficient arena with an
elegant curved square form
Figure 2 42 - Ras Abu Aboud stadium built to be reused (google images)
This innovative stadium will also allow it to be completely disassembled after the World Cup
Precisely many elements of the arena including all 40000 seats the containers and even the roof
will be reused providing valuable infrastructures to sports and non-sports projects elsewhere
Moreover off-site manufacturing can reduce emissions much more than conventional
method In 2009 Al-Hussein et al focused on the construction phase of modular and conventional
buildings and compared their CO2 equivalent emissions They analysed a 42-suite multi-family four-
story residential modular building located in Alberta Canada All the construction activities needed
for this building and a similar conventional building such as material delivery transportation
workforce trips equipment usage and winter heating were identified separately Therefore CO2
emissions from each of these activities were quantified The authorsrsquo analyses showed that modular
processes led to a 43 reduction in CO2 emissions compared to on-site processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
37 | P a g e
Table 2 4 - Environmental Benefits
While the on-site construction disturbs the sitersquos neighbourhood with noise dust congestion
and waste modular construction performs better by providing minimal project site disturbance
(Mohammad Kamali2016) Since most of the construction process takes place offsite there is less
impact on the project surroundings Modular construction reduces the number of vehicles and heavy
equipment required on site which translates into reduced pollution and less site disruption
Figure 2 43 - The dust of a construction site in Beijing (wwwchinaorgcn) vs Cadolto factory site (wwwcadoltocom)
Energy consumption in the occupancy phase of modular buildings dominates the other life
cycle phases This phase alone accounts for more than 70 and up to 98 of energy consumption and
consequent impacts over the life cycle of buildings while the contribution of the construction phase
is relatively small (M Kamali 2016) Sustainable material selection optimum modular factory
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
38 | P a g e
location and availability of labour which lead to less embodied energy consumption are effective
opportunities to reduce the life cycle energy consumption and the subsequent environmental
impacts In addition a smart design of insulation which is advanced in modular buildings can achieve
a high amount of energy use saving during the operation phase
Figure 2 44 - various layers of a module building unit including insulations (wwwsteelconstructioninfo)
Health and security benefits
When it comes to safety modular method can offer advantages for both phases (construction
and operation) to workers and future users Converting possibly dangerous on-site activities to an off-
site plant that there the supervision and control is much higher can reduce the accidents for the
workforces and the products It is obvious that the safety plan can be applied much more efficient in
a factory environment Not only is there a reduced risk of slips trips and falls ndash particularly as work
at height is reduced but there is also a reduction in onsite activity thus ensuring health and safety
always remains a top priority from start to finish
Furthermore if necessary factory operations can continue 247 with less risk of noise and
disruption to workers Work is also unaffected by the weather and other environmental delays which
could result in the project being turned around even quicker
On the other side during the operation phase safety can be improved for instance fire
protection can be designed by using multiple insulations and protectors inside the panels
One of the examples is Actavorsquos plan for Ensuring everyonersquos safety is at the heart of Actavo
what does and in line with this they have developed the HEART (Help Eliminate All Risks Today)
procedure Devised and implemented in the continuous effort to create an accident and incident-free
environment the HEART behavioural safety observation process sets the whole Actavo teamrsquos
expectation every injury is preventable so do not let any happen (Hannah Vickers b4edcom)
Modular construction generally achieves these requirements using fire-resistant plasterboard
conforming to BS EN 520 Alternative materials such as cement particle board and gypsum fibre board
may also be used in combination with plasterboard as the facing layer In residential construction
each dwelling usually forms a separate fire compartment All walls and floors that provide a separating
function between compartments require 60 minutes fire resistance In hotels and other residential
buildings each bedroom may form its own compartment (wwwsteelconstructioninfo)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
39 | P a g e
Figure 2 45 - Compartment floor at junction with external wall and compartment wall (wwwsteelconstructioninfo)
Social-Laboral benefits
Most of the mentioned benefits including economic scheduling environmental and safety
advantages have direct effect on social well-being as well Therefore they can also be named in this
section Future users can benefit from the quality of building energy savings etc which leads to
costumerrsquos satisfaction among the public Due to the shorter on-site schedule there are fewer
negative impacts on local businesses urban beauty image than conventional constructions Also
modular construction demands more skilled workforce and experts which can create more jobs for
these group of labour in the regions that struggle with high unemployment rates
In addition every industry needs to trust innovations in order to improve the science and help
the innovator to break limitations and explore new alternatives to solve problems Modular
construction as it was mentioned can be a great solution for the productivity problem in construction
industry and by applying these method it is possible to even find more solutions in the future which
can increase these rate more or solve other problems that nowadays are common among players of
construction industry Table 2 5 - Health and safety amp Social-Laboral advantages
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
40 | P a g e
Modular Construction role in COIVD-19 Pandemic
Recognizing the urgent need to create modular critical care units for rapidly growing numbers
of COVID-19 patients HGA Architects and Engineers partnered with Boldt Construction to design and
build a new system within a noticeably short timeframe ldquoThe initial idea was to provide rapid
response for hospitals and build a product with off-the-shelf readily available parts because we did
not know what the supply chain would be like Over the course of three weeks we went from concept
to full design and fabrication was underwayrdquo reports Ben Bruns executive vice president of Boldt
Construction in Appleton Wis (Rapid Response by Barbara Horwitz-Bennett 2020) The final product
was a prefabricated modular solution for assembling field hospitals capable of providing airborne
infection isolation rooms
Figure 2 46 - New modular construction solution can be deployed as stand-alone hospitals or for use inside convention
centres arenas and temporary structures Image courtesy of HGA and The Boldt Company (prismpubcom)
These Strategic Temporary Acuity-Adaptable Treatment (STAAT) units are isolation units with
enough clearance for safe bed transfers and accommodate equipment and a reclining chair These
multifunctional modules can be used as supplemental interior isolation rooms within an existing
system of care as a modular system connected to an existing hospitalrsquos infrastructure or as a self-
sufficient temporary hospital with its own infrastructure
Figure 2 47 - Self-Sufficient Temporary Hospital with Infrastructure Image courtesy of HGA and The Boldt Company
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
41 | P a g e
PCL Construction has come up with a similar solution in collaboration with Thor Plumbing and
Heating f-BLOK Architecture EH Price Industries and P4 Electrical Contractors Called ldquoQuaran-Tin
Podsrdquo the units are emergency response modular isolationcare rooms that provide temporary and
reusable emergency isolation for care and treatment of COVID-19 patients Each unit is self-contained
with built-in power heating and cooling as well as connections for medical gas oxygen and vacuum
Highly scalable and customizable the pod is continuously negatively pressurized and all the exhaust
is HEPA filtered Citizen Care Pod is a smart screening and testing pod that integrates intelligent
technology within a modular design to support a safe responsible recovery for governments
businesses and communities Customizable with the capabilities to enable full-on mobile COVID-19
testing in high-traffic environments the project will help in testing screening and eventually
vaccination on a mass scale (Christele Harrouk on archdailycom)
Figure 2 48 - Emergency response modular isolationcare rooms by PCL construction (archdailycom)
The Citizen Care Pod is a turnkey solution that accelerates recovery for businesses and public
institutions such as airports offices sports and entertainment complexes construction sites and
more by rebuilding staff and customer confidence that your organization is equipped to ensure their
safety
Unfortunately the COVID-19 pandemic is only intensifying the housing crisis Further
complicating the issue is the fact that a significant percentage of skilled labour workers will be retiring
within the next couple years which will significantly impact the construction industry As stated in
MBIrsquos ldquoThe US Construction Industry A National Crisis Loomingrdquo there are currently not enough
skilled workers to build all of the projects that need to be built in the same manner in which they have
been built in the past ldquoThere is no other choicerdquo advises Hardiman ldquoIt is now time for our
policymakers to start looking at alternative ways to build everything and we think that modular
construction should be a part of that solutionrdquo Along these lines the COVID-1 Response Page also
includes links to articles illustrating how MBI membersrsquo systems and facilities are currently being used
in housing infrastructure and COVID-19-related projects
Review on common challenges
Initial costs
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
42 | P a g e
To start the modular construction method in an area there will be a significant investment
to establish a production plan and then designing team who must work alongside the execution
engineers parallelly in the design phase
factory cost Like any other industry modular construction demands a production line which
is an off-site plan with a supply chain based on 3D volumetric products First the off-site plan must be
designed based on the local requirements amount of demands availability of experts and labours and
budget that manufactures are willing to invest on this technology These factories are mostly
expensive to be build and the issue of production costs will always be a barrier to innovation in
modular construction because both the client and the architect will expect lower fabrication costs
However the art of every industrial innovative player is to study the economic pros and cons
of issued technology and then the industrial expert by doing couple trade-offs between the benefits
and disadvantages can make the decision whether to apply the new method or not Modular
construction is not an exception of this fact A local study can tell the investors if the approach would
be reasonable in all term and not only economic terms for the society or not Thus due to the
economic benefits that were mentioned earlier in numbers of regions which the labour salaries are
higher and the balance between transportation costs primary material access and costs experts
existence local market and their demand of real state and initial costs is more favourable modular
construction can be the best solution to apply On the other hand nowadays there are numbers of
region which the investors of industry are eager to use innovative method with higher costs that have
positive influence on environment and public health in which modular construction is more friendly
than the conventional method
Figure 2 49 -Balance between Initial costs and Economical benefits
First design costs and errors By changing the traditional construction products a change of
design is also demanded Modular design can be based by the production linersquos technologies the
budget of manufacturer and the final products quantity and quality In the earlier discussions about
design phase the complexity of 3D volumetric design had been mentioned and surely in the first
attempts would be expensive for the manufacturer However if the design could focus more on the
standardization of elements repetition in production line and consider integrate with modern design
software in order to provide more executive details and minimize the future errors and reworks the
rework cost can be eliminated and the design sample can be used for numbers of projects as a
catalogue with few changes Therefore by having these advantages the initial design cost can be
recovered soon and even make more benefit by the time
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
43 | P a g e
Architectural challenges
One of the main group of experts who have argues about modular buildings are the
architectures who always suffer from limitations that this approach puts on their design process Most
of these challenges are mentioned below
bull Manufacturing technologies effect on the design One of the challenges which the manufacturers
can struggle is to consider a production line that be able to produce a wide range of product so
that there will be fewer limitations on the design phase This goal can often be impossible because
of the predicted budget of investors limited area of production plant and lack of technologies
Thus it is the architect who must be flexible with the production line and its boundaries
Moreover it is the art of the architect which can maintain a balance between ability of production
line and attractivity and innovation of the final product for the market and the industry
bull Transportation boundaries on architecture It is a fact that the transportation of modular
construction have puts limitations on the architectrsquos works The modules must obey the
obligations and regulations of the region that want to be transported in Therefore architects
must design modules which are transportable and minimize negative economic and timing effects
for the project In addition in the designing process environmental aspects which can be
happening during the transportation phase must be considered
bull Regional architecture specializations There are cases in which an off-site production plant ships
same model of modules for numbers of projects which are going to be assembled in variety of
regions with different climate cultural architecture and local construction regulations which can
surely have negative effects on the regionrsquos construction industry real estate market and cultural
architecture aspects For instance the harmony of the angel of sunlight and the windows
formation and dimensions in a residential building located in eastern region and western ones
which reduce or increase the sunlight absorption inside the building for the residents In this case
if the same form of modules will be transported and assembled without of any changes the
unsatisfaction of future users can be increased and in a result the demands can be reduce
significantly which could cause a failure for the real estate and construction industry of the region
In terms of architectural culture modular manufacturers must consider the traditional
architecture of the location in the designs in order to make sure that the harmony will be kept
among the present buildings and modular ones
bull Lack of knowledge about modular buildings among architects Manufacturers argue about the
lack of enough knowledge of architects about the modular fabrication process The third-party
inspections and approval process Transportation methods and its boundaries Onsite assembly
procedures The cross section of a modular structure which can reduce their understandings from
manufacturerrsquos demands of project and result a unsuitable design for the final products These
disagreements come with every innovation in civil engineering society which architect must follow
their lead most of the time The solution for this cause is to educate the architects by planning
workshops by the manufacturers or internships during a project so that architects can improve
their knowledge and gain actual experiences by observe and participating in real projects
bull Unfeasible on-site finishing Common architectural innovative designs focus a lot on finishing
works in order to gain attentions of buyer and improve attractiveness of buildings There are
different views about this subject Some manufacturers think that the finishing process must be
as simple as possible or minimize the schedule and costs on-site to benefit from the project On
the other hand architects believe that the modular buildings are not attractive enough because
of repetition in their design and try to focus on finishing process to make them desirable to the
market or improve the products in architectonic point of view
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
44 | P a g e
Transportation challenges
By transferring most of the construction activity to the off-site plant transportation plays a
vital role in the projects so that in case of poor logistic management can damage numbers of benefits
which were achieved in the factory plant
bull Dimensional and weight barriers based on type of transportation The type and technologies of
every modular constructorrsquos logistics can affect the project from the design phase to the on-site
assembly These effects can change the dimensions weight and structural features of the product
For instance modular structures transported on a flatback trailer will be limited in length width
and weight based on the physical capacity of the truck Components fit into shipping containers
are best suited for projects overseas because the structural integrity of the containers allows for
unorganized stacking However components will be limited by the interior dimensions of the
container in length width and height (Joseph M Schoenborn 2012)
bull Long distance transportation and lack of existence of local factory Off-site plants are not
available for every site location in numbers of states or even regions yet because of poor
development of these method in those regions Therefore in some cases the modules must
shipped even overseas to the site location to be assembled Long distance and its possible
difficulties during ground or marine transportation can bring extra costs for the project which
must be studied economically before the biding process
bull State regulations on structures dimensions and strategic issues Estate laws can always put
boundaries on construction industry and modular constructors are not an exception Every region
has its structural and transportation regulation which limits the final product In addition estate
approval during transportation phase can harm the projectrsquos scheduling program and put delays
on the arrivals or even occasional penalties which causes extra costs in the budget
bull Negative effects from environment on the modules during the transportation While the
modules are being transported to the site these products are in direct exposure to the
environment such as sunlight rain wind and other natural causes By the time possible damages
can be appeared in the modules which in some cases can be too critical that module need to be
repaired or replaced to be used On the other hand ground transportations can cause vibrations
on the trucks and its loads and the intensity of damage generally increases with the roughness of
the road surface which in some creates cracks or more critical damages on the structural element
installations or finishing The solution is to use To minimise transportation difficulties the vehicle
having vibration absorber can be used to minimise damage due to vibration and additional
precautions need to be considered for wider modules while low bed transport vehicles are
preferable for transporting taller modules (W Ferdows 2019) Moreover loading and offloading
processes must be carefully done by precise strategy and adequate equipment in order to avoid
the harms on the products
bull Transportable materials There are two terms which force modular constructors to use advanced
and high-quality materials transportation and design situations Transportation as it mentioned
earlier puts limitations on the final product and force the constructors to use material which have
less weight more against resistance road vibrations and endurance against sunlight and humidity
exposures In one word these materials must be part of a final product which can be
transportable Often these materials add costs on the project because they are more expensive
than the ones which have been used in conventional buildings All properties need to be
structurally sound in situ but units built using offsite construction methods also need to be
structurally sound whilst being raised and lowered throughout the transportation and assembly
stages of the process Key structural elements such as beams columns and potentially walls and
floors must be repeated in three-dimensional modules for transportation purposes This can
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
45 | P a g e
significantly increase material costs depending on the material choice and level of design
optimization (McKinsey amp Company 2019)
On the other hand numerous benefits which modular construction has in terms of material
such as less reworks discount on massive offers no exposure to natural causes and its off-site storage
and less waste during the production can assure the constructors that these challenges can overcome
the fact that modular buildings work better than conventional ones in a material criteria
Wrong perceptions among public and real estate market
Innovation without correct publicity brings wrong perception among people and markets
Also errors bad experiences of users and unprofessional works can change the mindsets quickly by
unsatisfying the users and in result investors During a period in past off-site accommodations were
mostly for temporary uses with low quality material and less functional features The demands of
permanent housing raised after a break such as world wars for those who lost their houses and
refugees that wanted to live abroad Therefore numbers of companies started to modify their off-site
products in order to have more lifetime and serviceability However there were constructors who
could not provide buildings with better functional services and the users became unsatisfied and lost
their trust in these products This wrong perception had been raised even until now that off-site
building such as modular ones will not serve a long lifetime and have low quality material incommode
and unattractive design and a poor functionality Obliviously bad perception of people will reduce the
demands and destroys the market as well
Today the industry recognizes the need for durable construction for even temporary uses
making it possible to move and re-use full buildings So a lack of knowledge among consumers as to
what is possible can prevent design innovation In order to overcome the stigma sometimes associated
with modular construction manufacturers attempt to offer a built product indistinguishable from one
built onsite Therefore the industry advertises a direct alternative to onsite construction In a
comparative analysis of the two processes time savings and worker safety stand out as the primary
advantages of modular construction over onsite construction The building manufacturing process
itself construction in a controlled environment with access to advanced technology is an evolution
of the art of building which is traditionally slow to evolve The modular building industry therefore
should advertise a different building product altogether featuring design innovation and ingenuity
executed through advanced building techniques (Joseph M Schoenborn 2012)
Moreover in order to raise the demands among the public who can be future users a range
of positive publicity about the environmental advantages such as less emission economic savings like
less energy bills cheaper and easier maintenance processes during the operation phase and faster
construction process which help them to be accommodate sooner can create a positive mindset
among the public In addition post-sell services from constructors such as better assurance policies
for buyers maintenance services and offering loans to customers who are in emergency
accommodation needs can change the market significantly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
46 | P a g e
Figure 2 50 - Spanish company INHAUS offers after-sale service for 10 years in modular projects (casasinhauscom)
Integration of advanced software
As it mentioned before modular construction can benefit from using innovative software in
their designing phase in order to be more precise on planning and provide detail for the production
line One of these software programs is BIM which can be used in design construction phase on-site
assemble and even operation phase However despite its advantages there will be some challenges
as well The greatest challenge of using BIM in construction project is the implementation process
itself regardless of the software capabilities Development of accurate BIM model requires extensive
resources and in-depth knowledge of construction methods and process Most small or medium firm
could not afford the special team and man hours to aligning BIM (Na Lu and Thomas Korman 2010)
Other than finance and organizational issues the project team has experienced legal challenges as
well The use of BIM technology encourages multi-disciplinary collaboration which contrasts to
defining responsibility to each party and then assigning liability issues among the parties In addition
using BIM models instead of traditional contract documents raises questions on insurance coverage
and confidentiality exposure Ownership and control of the model use and distribution of the model
and intellectual property rights are some of the issues that need to be addressed while BIM
implementation being adopted in construction industry
Redefining the contracts
Due to the changes over the responsibilities of every participants the amount of their
influence on projectrsquos activities and transferring most of the work to the off-site plant a new way to
contracting is needed in order to optimize the relationship between the owner designers and
manufacturers during all phases of the project Here are some of the common types of contracts which
are being used among modular building industry
bull Design-build The architect modular manufacturer and onsite general contractor are
hired as a team and assume the responsibilities of design and construction together DB contract can
be named one of most traditional types of contracts that would create an integration between all the
parties of a project Due to the design-build nature of modular construction a close partnership is
demanding during the project phases
bull Design-bid-build After the architectrsquos design has been approved by the client a
competitive bidding process takes place This results in a greater disconnect between parties The
common gap between participate happen a lot in this type of contract which frequently can cause
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 2 State of the art
47 | P a g e
misunderstandings about responsibilities of each expert incomplete information about the project
design or executive details and lack of transparency among the participants
bull Negotiated bid The modular manufacturer is hired first by the client to find the
appropriate architect and onsite general contractor that can be hired within the constraints of a
budget This concept may increase bonding between experts and improve everyonersquos understandings
about many aspects of the project But the budget will decide whether the quality level design
enhancement can meet the clientrsquos requirements or not In addition in case of clientrsquos approval the
question would be the future userrsquos satisfaction can be achieved or not due to the budget limitations
on the project quality level
bull Certified Modular Architect (CMA) A sustained relationship between an architect
and a manufacturer can be developed over multiple projects Therefore a certification process
providing training and continuing education can be introduced to the modular building industry An
architect intimately familiar with modular construction is best suited to handle coordination issues
that arise when work is being done in the factory and onsite simultaneously A it mentioned earlier
architects understanding and knowledges is critical to avoid possible mistakes and unsuitable designs
for modules Therefore this certified education which can be called as a semi-professional internship
for the design team in order to be present at every phase of the project
Supply chain-transportation-onsite assembly management errors
One of the main objectives to use prefabricated elements in construction is to raise the
productivity in execution phase which is mostly happens in off-site plant As it mentioned before there
is a supply chain in manufacturing plant and its productivity is depended to many key factors which
will happen outside of the factory Continuity of assembly operation is one of them which would be
happening in parallel with off-site supply chain After the modules were prepared to be transported
to the site the transportation system must be synchronized with the factory delivery and assembly
demands If any delays may happen during the transportation would affect the both origin and
destination scheduling storage policies and demands
On the other hand assembly line also must on-time and well-communicated with off-site
plant experts because any changes in execution phase can make huge negative impacts on supply
chain productivity Therefore these three important phases must plan based by on-site demands
supply chain productivity execution management and transportation systems
Figure 2 51 - synchronization between supply chain transportation and on-site assembly
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
48 | P a g e
3 Common challenges in modular construction industry by a
survey Methodology
Objective
This study used qualitative research and specifically a grounded theory methodology to
uncover more information about advantages of modular construction and its constraints or barriers
to develop this method in the market Qualitative research emphasizes the influence of the researcher
on the data collected
Role of the researcher
In this study I acted as the sole researcher who was responsible to design questions based by
literature reviews and then by creating an online survey form try to collect the data from the
participants
Ethical considerations
To protect the rights and guarantee the safety of participantrsquos information following actions
were done
1) The research objective and process were made clear to the participants
2) The collected data was used for research objectives only
3) Only eligible participants who are modular constructors and manufacturers were
chosen for this survey
4) The access option to the survey information gave to the participants after the
research was finished
5) The anonymity of the participants was maintained
6) The name of the participant and their brand was remained confidential for all roles
even the researcher to obey the law of data protection
Survey setting
Due to the emergency restrictions which caused by a virus pandemic across the world several
options were unavailable to be done such as face to face interviews factory visits and project site
practices Therefore online interview was the only solution which can be happen without any danger
for participants and researcher In most regions construction companies are suffering from a full shut
down on their production line and on-site projects so that access to these participants became even
harder than usual Thus an online survey form by office forms was chosen for this research so that
the participants can answer the form questions at any time and location with ease to answer by
multiple accesses to the formrsquos link (Figure 31)
This survey forms had been sent by email to the official addresses that were mentioned in
their websites for contact The priority in choosing the recipients were the construction managers
project managers and executive engineers so that the information will be collected from the operation
managers who have the most technical experience and have the most knowledge with construction
phases from off-site production to on-site installation This could also help the survey to find the
challenges during the construction that were not able to be visited due to the restrictions of global
pandemic
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
49 | P a g e
Figure 3 1 - Online office forms for survey use
The estimated time was reduced to 13min with the most important questions to improve the
efficiency and be timely reasonable for the participants
Development of questionnaire
After hours of study on numbers of articles which have focused on challenges in modular
construction industry several were found that have lack of scientific scope and recommended
solutions Therefore many of the questions were designed to first shed a light on the potential
advantages which have not been mentioned specific and completely unknown for the industry For
instance the social benefits which came immensely useful during the COVID-19 pandemic for health
centres and medical infrastructure etc Moreover a lack of inconsistency between industry and
science came to notice which shown a massive gap between these two important roles in construction
industry This gap explains that the scientific researchers in some areas have the minimum contact
with industrial players in construction world in comparison with other industries which the opposite
situation is applied To fill this gap questions were designed in a way which have an origin of scientific
researches and direct and first-hand information from the construction industry players which are
constructors modules manufacturers etc
Development path of questions can be explained as critical path to the best details of each
criteria than can obtain useful information from participants In terms of advantages the benefits
which were identified from literatures were ordered and asked form participants to be confirmed and
validated by the industry players in real project cases For instance in an environmental point of view
Reduction in Energy Consumption was identified in literatures and had been asked among participants
to confirm the hypothesis that modular construction can reduce the energy consumption in
comparison with traditional methods (Figure 32)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
50 | P a g e
Figure 3 2 - Questionnaire development
Participant profile
Experience amp professions
As the ldquoTable 31rdquo explains information from five companies have been selected for this
survey with variety of backgrounds from pioneers to well-experienced players in industry with over
than 120 years of experience in the modular construction society as constructors and modular
manufacturers The experts who answered have different roles in the industry from CEO to architect
and sales managers so that the data can have more perspectives of views on the questions such as
sales market and design process to project management Table 3 1 - Participantrsquos profiles
Because of diversity in the influence of challenges between massive international builders and
local players these five companies responds have been compared to each other from company C
which is a local constructor to company E that is currently executing modular projects in 80 countries
with approximately 6000 modules build annually
Types of materials in some cases can have different statistics in results For instance in
modular construction which steel and wood modules are more often used in projects can produce
various amount of CO2 emissions and waste or recycle process can be done with more ease For that
reason these survey all types of materials are considered including steel modules concrete modules
and wood modules There is also an argue that some benefits and challenges cannot be seen in unique
projects with more repetition in production of elements and mass production such as hotels and
schools while in residential projects can exists more than the others To cover all the contrasts of
60 of participants
can acheive a 30-40
reduction energy
consumption
A Our homes are not positive from an energy
perspective
B We can finish a 4 months traditional project in 8-10 weeks and Energy consumption of a factory is known and relatively constant on a weekly
E 30 reduction in energy consumption
Modular construction can
reduce the energy consumption up
to 30 in compariosn with
conventional methods
QsCompany A B C D E
Years of company experience 10-15 10-15 20-30 20-30 30-50
Position of participant CEO Sales Manager Design Architect Quantity Surveyor Foreign Trade Manager
Professional experience 15 13 30 NA 3
No of employeesfactoryModules build annually 801200 1301490 151- 50280 25026000
Type of material(WoodSteelConcrete) W amp S W W W S amp Conter amp fiber cabins
Types of Projects (ResedentialSchoolsHospitalCommercial) R R amp S amp C R R amp S amp C amp H R amp S amp C amp H
Use of BIM Yes No No No No
Level of automation 20 reaching up to 80 20 Off-site 60 On-site 20 20 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
51 | P a g e
information these companies have been selected that are involved in all types of modular building
projects including residential hospitals schools and commercials buildings
As it mentioned before BIM program can advance the projects in many ways however
unfortunately among these participants only company A is able to benefit from this software from 0
to 100 of the project Therefore the further arranged interview focused on BIM Function was
cancelled and may be done in the future investigations
Automation can play an important role in improving the productivity and sustainability of
construction processes as a part of ldquoindustrialization in constructionrdquo movement Among survey
participants the minimum automation level in off-site plants is 20 and maximum of 60 and in on-site
activities can be up to 40 In addition company A claimed that in near future their automation can
reach up to 80 which is an innovative move in construction industry On the other hand company
with over than 6000 modules build annually have a significant 60 of automation in their plant which
shown a massive interest of investment on this technology In addition automation application
difficulty have direct relation with the type of materials used in modules and type of the projects which
as Table 31 illustrates company E with the most variety in project types and materials use have
achieved a huge success in application of automation with a level of 60 which also helped a lot to
expand their market overseas
Data collection
General information
All the received information has been attached in ldquoAnnex 1rdquo where the responds are not
edited and mentioned in the original shape Here are the shorter versions of responds
bull Motivations to choose modular construction over traditional
To bring the attention of investors to an innovative method reasonable motivations are
needed which can be the current demands of market economic profits and environmental benefits
Therefore it was necessary to identify the motivations of these companies to start a modular
construction form Economic advantage for most of these has a priority not just for being profitable
but for being able to develop their dominance in the future On the other hand innovation has an
approximately same amount of interest which explain the reason behind choosing modular method
that is one of the most innovative off-site construction methods in the industry
The fact that mentioned before in literature reviews high demands in the market and the lack
of provide by construction players is one of most important reasons to apply a fast and high-quality
solution for reach the satisfaction of housing market Shorter schedule and environmental benefits
took the next places of priority in motivations for these companies which are also important for sure
Figure 3 3 - Participants motivations to start a modular company
28
9
18
18
27
Economic benefits
Enviromental benefits
Shorter schedule due to the need
High demands of housing in themarket and lack of provide
Innovation
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
52 | P a g e
bull Built in factory panelssubcontracted panels used in modules
All five companies are manufacturing the panels that used in modules by their own inside the
off-site plant which as it mentioned earlier the selected participants have a variety of production rates
and by this information that they are able build their own panels it can be said that their production
is 100 off-site However in the case of company E which is a massive international modular player
there are some types of modules that are being provided from domestic market because of economic
feasibility issues
Economic issues
bull No of labourLess wages of salaryAdded value in each hour of workneed of
special workforce
Generally the participants mentioned that there fewer number of workers are needed on and
off site in comparison with traditional method About the amount of salary wages company A
confirms that for each hour of work off-site less amount wages are being paid to workers On the other
hand the shorter schedule of projects in modular projects can reduce the payments as well The fact
that most of the participants are emphasizing is that the efficiency of work and added value of
activities off-site are much more than the on-site traditional projects where company A acclaimed
that in terms of efficiency ldquo1 hour in the factory is equal to 4 hours on-siterdquo
Environmental status
bull Life cycle duration of products and material recycle
Company B acclaimed that they do have multiple solutions for each materials that theyrsquore
using in their modules for instance the unusable drywalls and PVC materials which they send for
recycling or the woods that would use into mulch products or for heating by others
Company E told that their products have a 50 years life span which is the same as a lifetime of
traditional build residential house However company C have some difficulties in recycle and reuse of
their elements because of unportable feature of their products
bull Integration the modules with other innovative technologies
Four of these five companies confirmed that their products have the option to integrate with
other innovative technologies such as self-powered homes by solar panels and also using advanced
insulation technics made by non-petroleum materials in their panels to reduce the energy
consumption during operation phase
bull Waste reduction
Company A acclaimed that their production line generates significant amount of 70 less
waste in comparison with traditional method The rest of the companies focused on carbon footprint
reduction and were able to reduce it 15 less that traditional method by choosing environmentally
friendly technologies in production and wise choice of materials for their products
bull Reuse of structural and non-structural elements in projects
Three of five participants confirmed that they have the ability to re-use their products in the
next projects in order to reduce the waste and energy consumption during the manufacturing
processes Type of the projects and material have the direct relation with the potential of reusability
in elements and due to the variety that the participant have in both criterions the potential is variable
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
53 | P a g e
Figure 3 4 - Re-use potential
bull Reduction in Energy Consumption
Company E mentions that modular construction can achieve a 30 of energy saving in
comparison with traditional site-build method while company A acclaimed that their homes are not
positive from an energy perspective Company B gave more details on energy consumption by making
a comparison between off-site activities and on-site traditional construction and acclaimed that due
to the shorter schedules in off-site production energy consumptions can be reduced up to 50 They
mentioned that ldquoEnergy consumption of a factory is known and relatively constant on a weekly
monthly and annual basis A competent and experienced modular builder can many times finish the
entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-
built house could require as much as 4 months for the same completionrdquo
Social Benefits
bull Delivery of projects for emergency services during COVID-19 Period
As it mentioned earlier due to the virus pandemic that is happening at moment in all around
the world a rapid response is needed more than ever for emergency services for health organizations
and according to this survey one of these companies is providing products for this cause which can be
a good news and accounted as a social benefits for this method of construction
Figure 3 5 - Contribution in Covid19 epidemic
bull Providing post-sale services for clients
In contrast with conventional construction which just have the responsibility until the delivery
of the project modular constructors because of their industrial profile have the ability to offer post-
No40
Yes60
Reuse the structuralnon-structural elements projects
No
Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
54 | P a g e
sale services to the clients such maintenances upgrades etc due to the results of this survey four of
these five companies confirmed the availability of post-sale services for their clients
Figure 3 6 - Post sale services por future clients
Initial costs
bull Initial investment and its Payback period
Company A claims that their initial investment to establish their company was about 20 million
Canadian dollar and its payback period was 5 years Company E had the amount of 15 million USD with
the same 5 years period However company C like many of the older players in modular construction
industry who started way earlier cannot estimate their initial investment
bull Factors that can change the initial costs
There are factors which can make a change in initial costs of companies The participants
prioritized these 6 chosen factors starting with product types and production range with 31 of
importance among others Level of automation took 25 share of the pie chart which has direct
relation with the initial costs Off-site plantrsquos location has 19 of efficiency on starting costs and
furthermore the quantity of sub-contracted players in the projects achieved 13 of the graph Finally
financing and design enhancement have the minimum equal shares of 6 which despite of being the
last factors have the efficiency on initial costs as well
Figure 3 7 - effective factors in initial investments for start-up companies
6
25
31
13
19
6
Factors that effect on initial costs
Design enhancment Level of automation
Product types and production range Less sub-contracted
site location Financing
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
55 | P a g e
Design limitations
bull Design boundaries caused by production line
Company A mentioned the subassemblies as the main element to be considered in design
phase while company D and company B introduce a maximum dimension for their production lines to
be economically viable for transportation costs In addition to those company C and company E
confirmed that there are no boundaries for the designer caused by the production lines because of
their wise choice of prefabrication methods
bull Lack of knowledge from architectsdesign engineers about production processes
transportation limitations etc
One of the main problems of start-up companies and the experts who join the modular
construction industry is the lack of knowledge about off-site processes and transportation limits
Three of five participants confirmed that there is lack of knowledge in these area from designers
Figure 3 8 - Lack of knowledge among designers and engineers
Transportation Limitations
bull Transportation regulation effects on modular projects
Three of five participants confirmed that the regulation by transport administrative can be
harmful for the projects such as extra costs or time delays on schedule Company A mentioned the
time delays in giving permits to the manufacturers and constructors which can damage the
synchronization between production line and on-site installation by reducing the speed of
transportation of elements to the site Company B added information about transportation system of
some states in America which use the term ldquoSuper Loadsrdquo to put limits on oversized shipping that
increases the cost and time on the project On the other side Company C as a strategy to avoid this
problem used legal load limits in their design instructions so that their products will obey the
regulations
bull Transportation boundaries on material choice and project costs
Company B D and E confirmed that the terms of special transportable material will not add
extra costs on the project Company A acclaimed that the extra costs by transportation can be offset
by speed of production and reduced financing costs for the project
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
56 | P a g e
Project management challenges
bull Difficulties in using automation in off-site production
In this survey based on literature reviews 4 main reasons for difficulties of using automation
in off-site production were selected to ask the participants Integration with advanced software and
high expenses of application in production line took approximately 60 of importance among others
Codding problem is another major problem in this subject which have 28 of pie chart In addition
company A demanded ldquoAn international coddingrdquo as a solution for this problem The last section
belongs to ldquolower salaries of manual processesrdquo which has the minimum importance of 14 among
participants
Figure 3 9 - challenges of using automation in off-site plants
bull Contracting problems
Starting with company A which acclaims that every state has its own code and the lack of a
universal code can bring challenges for modular players
Company B explained about the misunderstanding by final client who is the end home buyer
who ldquobelieves the factory to be the builder and the actual independent builder to be a sales agent
for the factoryrdquo Their recommended solution for this problem is to define the relationship between
the participants of projects their responsibilities by social media and requiring the builders customer
to sign a disclosure acknowledgement from that describes the relationship in detail
Company C mentioned a financial challenge caused by the banks in the projects that are
financed by them (Banks) which do not consider the project done until erected on-site This issue
creates pressure on cash flow of project where bank finance is involved The only problem that
company E consider in terms of contracts is lack of timing on project delivery which is generally causes
by constructors or general contractors
bull Lack of synchronization between projectrsquos participants
To begin with company A believes that there is a lack of quality partners on site They explain
that the problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution Company B mentioned that the responsibility of ensuring
28
29
29
14
Difficulties in using automation in off-site production
Codding Integration with advanced software Cost Lower salaries of manual processes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
57 | P a g e
that the work is done properly belongs to the builder which any ldquodelays in this can result in postponed
transport of product and interest through demurrage charges
bull Sub-contractor for site planning and foundation phase
Company A uses local subcontractors for their site planning and foundation phases because
of variety of locations of their projects and ease of using local subcontractors Company B have only
the responsibility of modules production and defines the customer (the general
contractorindependent builder) responsibility to execute rest of the project phases have sub-
contractors if needed Company C does have sub-contractors for site-preparations and foundation
phases under direct supervision and the reason to not performing by their own is the high costs of
required equipment and not being portable for each project
bull Technology gap between sub-contractor and modular constructor
The only issue that were mentioned by participant is where company A recommended to ldquoto
educate most local subs on our process and reason for doing things a certain wayrdquo
Company B and C acclaimed that there are no challenges for the off-site production
Social challenges
bull Wrong perceptions among public and market
The only value that the market considers choosing modular method over traditional
construction is to be cheaper Company A says
According to company B experience in USA majority of people the media and even
professional engineers do not understand the capabilities of modular construction Many people
continue to confuse this form of construction with HUD on frame products
Another wrong perception that the publicmarket believes is that the prefabrication methods
limits the design options while Company C believe confirms that the reverse is the case
bull Solutions for resolving the wrong perceptions
Company A believes by using one of the main advantages of modular construction which is
shorter schedule the market can be dominated by modular projects and the more cases they deliver
the more recognised this method would be among the public and at the end the superior nature of
modular approach can be proved Company B addresses a solution in a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Company C acclaimed that advertising the modular advantages
among the public would be enough
Data analysis amp conclusions
The data from this survey can be used as an input data and prioritizations for the next chapter
which is decision-making process between four alternatives The solutions and recommendation will
be repeated at the recommendations at the final chapter as well Here are the conclusions about
advantages and challenges in modular construction mentioned by professional participants
Advantages
Economic benefits Generally apart from the other benefits as the participants mentioned
that there fewer number of workers are needed on and off site in comparison with traditional method
and Due to the shorter schedule of projects in modular projects can reduce the payments wages
Other fact that most of the participants are emphasizing is that the efficiency of work and added value
of activities off-site are much more than the on-site traditional projects
Environmental benefits Due to the variety of solutions for each material that they are using
in their modules there is high potential to send the used elements for recycling or would use into
mulch products A long lifetime span is acclaimed for the products which is close to the traditional
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
58 | P a g e
ones Majority of participants confirmed the literature concept that their products have the option to
integrate with other innovative technologies such as self-powered homes by solar panels and also
using advanced insulation technics made by non-petroleum materials in their panels to reduce the
energy consumption during operation phase In the waste management term there is a possibility for
production lines to generate significant amount of 70 less waste in comparison with traditional
method Moreover about carbon footprint reduction there is ability to reduce it 15 less that
traditional method by choosing environmentally friendly technologies in production and wise choice
of materials for products While there is argue that modular construction can achieve a 30 of energy
saving in comparison with traditional site-build method there are claims that their homes are not
positive from an energy perspective However this idea mentioned that by making a comparison
between off-site activities and on-site traditional construction due to the shorter schedules in off-site
production energy consumptions can be reduced up to 50
Social benefits As it was mentioned in literature reviews there are social benefits in modular
construction that can improve the satisfaction of clients Post-sale services for customers are possible
which is completely opposite to the traditional projectrsquos conditions
Challenges discussion
Initial costs It is obvious that a high amount of investment is needed to stablish an off-site
plant to start prefabrication of construction elements but the payback period is not that long that put
boundaries for start-up future players due to the collected information There are factors which can
make a change in initial costs of companies that are prioritized by the participants starting with
product types and production range level of automation which has direct relation with the initial
costs Off-site plantrsquos location the quantity of sub-contracted players in the projects and finally
financing and design enhancement have the minimum equal shares
Financial aids Financial assists which are crucial for kind of projects that are dependent to
these aids are not harmonized with modular project processes where there are argues that until the
first deliveries of elements to the site location and their assembly these aids are not reachable This
issue creates pressure on cash flow of project where bank finance is involved Changes in contract
conditions and education for financial supporters are recommended solutions to improve the
partnerships in projects
Design boundaries it was mentioned the subassemblies as the main element to be
considered in design phase while some players introduce a maximum dimension for their production
lines to be economically viable for transportation costs However there a possibility to eliminate the
boundaries for the designer by the production lines because by wise choice of prefabrication product
types
Lack of education The idea of lack of education among engineers and architects about off-
site construction methods was proved by the collected information which have to be resolved by
updating the education resources to innovative methods that can improve the productivity rates and
sustainability
Transportation regulations negative effects it is confirmed that the regulation by transport
administrative can be harmful for the projects such as extra costs or time delays on schedule Time
delays in giving permits to the manufacturers and constructors which can damage the synchronization
between production line and on-site installation by reducing the speed of transportation of elements
to the site A strategy to avoid this problem used legal load limits in their design instructions so that
their products will obey the regulations
Choice of transportable material effect In contrast with literature review which mentioned
the idea of extra costs by choices of transportable material this survey confirmed that the term of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 3 Online Survey about challenges
59 | P a g e
special transportable material will not add extra costs on the project Moreover the extra costs by
transportation can be offset by speed of production and reduced financing costs for the project
Automation use challenges Integration with advanced software and high expenses of
application in production line took approximately 60 of importance among others Codding problem
is another major problem in this subject In addition ldquoAn international coddingrdquo was mentioned as a
solution for this problem Every state has its own code and the lack of a universal code can bring
challenges for modular players ldquolower salaries of manual processesrdquo has the minimum importance
Defining responsibilities boundaries There is a misunderstanding by final client who is the
end home buyer who ldquobelieves the factory to be the builder and the actual independent builder to
be a sales agent for the factoryrdquo Their recommended solution for this problem is to define the
relationship between the participants of projects their responsibilities and requiring the builders
customer to sign a disclosure acknowledgement from that describes the relationship in detail
Lack of partnership among projectrsquos participants There is a lack of quality partners on site
The problem starts when on-site participants realize the advantages of modular construction they
tend to increase their prices for services which can increase the final prices of project Another
challenge which modular projects can face is the lack of delivery of project on agreed time with an
unacceptable quality of on-site execution The professionals answered that the responsibility of
ensuring that the work is done properly belongs to the builder which any ldquodelays in this can result in
postponed transport of product and interest through demurrage chargesrdquo
Wrong perception of publicmarket The only value that the market considers choosing
modular method over traditional construction is to be cheaper while majority of people the media
and even professional engineers do not understand the capabilities of modular construction Many
people continue to confuse this form of construction with HUD on frame products Another wrong
perception that the publicmarket believes is that the prefabrication methods limits the design
options while some players believe that the reverse is the case Therefore by using one of the main
advantages of modular construction which is shorter schedule the market can be dominated by
modular projects and the more cases they deliver the more recognised this method would be among
the public and at the end the superior nature of modular approach can be proved Another solution is
a form of cooperation between builders manufacturers architects and engineers to educate the
public by national entities such as Modular Home Builders Association
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
60 | P a g e
4 Decision making based on potential advantages among three
modular alternatives and conventional construction method in a
project by MIVES software Methodology
Objective
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria potential benefits can be recognised However to find out how much practical these benefits
are in the market several trade-offs must be done by professional tools such as project management
software programs which can take decisions based on the input data that receive
The objective of these thesis is to examine the practicality of modular construction by taking
the best decision among 4 alternatives including a conventional armed concrete building with steel
modular concrete modular and timber modular methods and see that the mentioned advantages can
lead the methods to become the best option to choose for building the project as a project
management point of view
What is MIVES
In order to make the most sustainable and reasonable decision among the alternatives a multi-
criteria decision-making program was used called ldquoMIVESrdquo MIVES is the acronym for Modelo
Integrado de Valor para una Evaluacioacuten Sostenible which means Integrated Value Model for a
Sustainable Assessment It is a multi-criteria methodology for decision making It allows transferring
the different characteristics of the objects to be evaluated to a series of homogeneous and
quantifiable parameters which facilitate the objectification of the choice
The MIVES methodology consists of creating a model that defines all the characteristic
features of the elements to be evaluated assigning them a function that allows converting the
different peculiarities of the alternatives into a common unit which we will call value Once the
amount of value for each alternative is obtained it can be used for a sustainable evaluation
(wwwdecaupcedu)
Data collection process
Case Study references
bull Journal of Cleaner Production (WAHammad 2019)
(httpsdoiorg101016jjclepro201904150)
This Fabolous multi-criteria comparison was done between two methods of conventional and
steel modular building in two cases case A which is a normal residential building and case B a school
building to measure the sustainability level of them in economic environmental and social areas The
location of this was considered in Sydney and central coast Australia and four BIM models had been
designed for each alternative in both cases The total floor area of Case A is 63 m2 (87m x 72m)
When adopting modular construction the granny flat is designed from 2 modules each module is
36m x 87m Case A was chosen as the study case to focus on because of type of the project that is
residential building
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
61 | P a g e
Figure 4 1 - Floor plans of case studies considered Case A) granny flat was chosen for this study (WAHammad 2019)
The purpose of this journal is to add sustainability criteria as main factors for constructors to
make a multi-dimension decision whether to use Modular construction for a project or continue with
conventional methods
Figure 4 2 - Cleaner Production journal methodology for make a comparison between modular and conventional methods
(Akbarnezhad 2019)
bull A comparative life cycle assessment (LCA) of concrete and steel-prefabricated
prefinished volumetric construction structures in Malaysia (Ali Tighnavard
Balasbaneh 2020)
(httpsdoiorg101007s11356-020-10141-3)
This researchrsquos focus is to compare two types of volumetric modules function in terms of cost
and LCA factors such as Greenhouse emission etc on a residential project with the approximate area
of 105m2 located in Malaysia based on local regulations Prefabricated Concrete Modules (PCM) and
Prefabricated Steel Modules (PSM) were considered for this project Recently Malaysian
administrative system has been pushing the companies and researchers to investigate on these types
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
62 | P a g e
of construction methods in order to measure the benefits and obstacles of using them in future project
and try to resolve the productivity problem in construction industry The construction industry in
Malaysia has been labelled ldquounproductiverdquo for its reliance on a large labour force and its use of non-
prefabricated strategies at a proper scale (Balasbaneh 2020)
Figure 4 3 - Architectural plan of residential project build with PCM and PSM (Balasbaneh 2020)
bull Modular vs Conventional Construction A Multi-Criteria Framework Approach
published at ISARC 2017 (AWA Hammada and A Akbarnezhad 2017)
This paper did a comparative analysis in cost time and carbon emissions by BIM models
Material and equipment libraries and existent databases on a project in the North-West of Sydney
involves the construction of a granny flat with dimensions 14 m by 16 m
Figure 4 4 - Case study of residential building studied (Hammad and Akbarnezhad 2017)
The framework of this papers based on the BIM model analysis with input data project actual
projectrsquos budget material and equipment used in the construction and environmental information in
database and then a comparative study on emissions during constructionmanufacturing schedule
and costs of project for crew material and equipment (Figure 45)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
63 | P a g e
Figure 4 5 - Framework for comparing between construction methods (Hammad and Akbarnezhad 2017)
bull Life cycle greenhouse gas emissions and energy analysis of prefabricated reusable
building modules published on Energy and Building (Lu Aye 2011)
(httpsdoiorg101016jenbuild201111049)
Aye and his team did a LCA study on three alternatives PSM PCM and PTM which were used
in a multi-residential building with 63 apartment units with area of 63 m2
Figure 4 6 - Architectural section of multi-residential building (Aye 2011)
The modules in this study were categorized in 4 main elements Exterior walls with insulation
panels Interior walls used for internal separation which mostly build with timber frames and plaster
boards Floors with plywood material on topping in all alternatives and ceilings with thick plaster
boards and steel concrete and timber parts as main elements (Figure 47)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
64 | P a g e
Figure 4 7 - Structural elements used in modules (Aye 2011)
bull Comparing Environmental Impacts of Building Modular and Conventional Homes in
the United States published at Construction Matters (John Quale 2012)
(httpsdoiorg101111j1530-9290201100424x)
Quale did also a comparative analysis focused on Environmental emissions on two PTM and
Conventional Timber building Three residential modular companies generally representative of the
eastern US modular industry supplied data on completed projects for this study including utility
bills worker commuting information building materials and waste procedures construction
schedules employee schedules and other relevant information (Quale 2012) 186 m2 two-story
home that is a model for one of the companies involved in the study
Figure 4 8 - Architectural section from the side and front of the two-story building (Quale 2012)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
65 | P a g e
Input data
4221 Alternatives
Four alternatives were selected for these study which are one conventional armed concrete
(Reinforced concrete RC) structure prefabricated steel modules (PSM) prefabricated concrete
modules (PCM) and prefabricated timber modules(PTM) that are most common solutions used by
contractors in the construction industry
4222 Requirement tree
These are groups of criteria which define a function to be evaluated A requirement usually
has several criteria Five requirements were selected based by literature review and the expertrsquos
opinions collected by survey among industrial players who were the participants of this questionnaire
Economic R1 time R2 environmental R3 safety R4 and social R5 requirements arranged in a way that
can examine the advantages adequately Time requirement were separated from economic one
because of importance due to high priority that have in the market to be chosen by the constructors
and clients In other words some clients and private builders choose the prefabrication methods such
as modular construction to save more time due to tight schedule that the project have Social and
safety requirements usually not being considered in sustainable decision-making processes but on this
study were included because the sustainability is not the only factor in project management
4223 Criteria
For each requirement a series of criteria are defined Criteria are the specific concepts that
the indicators contain the minimum unit to be quantified (wwwdecaupcedu) Each criterion was
chosen based on the importance among others efficiency on the project and availability of actual
amount and quantities in real cases over literature resources In other words the both advantages
and their functionality that modular construction have in comparison with traditional methods were
the main drivers to choose a criterion for each requirement as it mentioned earlier For economic
requirement cost of the project R1C1 was the only criteria that was considered which in the literatures
is expected to save 20 by choosing modular method in final cost (McKinsey amp Company 2019) while
experts in survey believe that the cost of transportation of prefabricated elements to the site can
compensate the difference with traditional method To examine these two opinions these criteria was
chosen In Time section the projectrsquos schedule R2C1 was only criteria to measure the important
advantage that the modular construction has Both literatures and expert agreed the time saving that
modular approach can bring to the project which is about 50
Figure 4 9 - Requirement tree and criteria for the decision-making program (MIVES)
R1 - Economic
R1C1 - Project cost
R2 - Time
R2C1 - Project schedule
R3 - Environmental
R3C1 - Energy consumption
R3C2 - Waste generation
R3C3 - Material consumption
R3C4 - Noise Polution
R3C5 - Greenhouse gas emission
R3C6 - Recycle
R3C7 - Embodied energy
R4 - Saftey
R4C1 - Injury risks
R4C2 - Protection from natural cuases
R5 - Social
R5C1 - Job status
R5C2 - Quality
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
66 | P a g e
Seven criteria were chosen to cover the environmental requirements for this decision-making
process based on the available data in literatures However in this section not only advantages of
modular methods were considered but in some areas conventional reinforced concrete showed
better results and this fact can improve the liability and practicality of final decision For instance the
embodied energy of steel modular building is 30 more than the conventional during the construction
but the saving caused by re-useability of element in modular method can almost compensate the gap
between these two methods Energy consumption R3C1 which is the energy consumed during the
constructionfabrication amount of Waste generated R3C2 in all alternatives Material consumption
R3C3 in each method Noise pollution R3C4 Greenhouse gas emission R3C5 Recycle of elements R3C6
and Embodied energy for each method were chosen in this section
Safety issue as it has mentioned before was added to decide further than sustainability
concept boundaries which include two criteria Injury risk for workers R4C1 and Protection of project
from nature causes R4C2
Finally Social benefits which are not as main factors to be considered by construction players
to use the modular methods but are important enough to pay attention and were compared as well
by two criteria Job status R5C1 and Quality R5C2
4224 Indicators
The indicators for this study came directly from scientific articles which most of them were
published few months ago and it can be said that the data which were used for this study is updated
with the latest achievements in modular construction industry
To begin with for economic measurements two indicators for the project cost were selected
total project cost R1C1I1 and costs stability R1C1R2 Total project cost R1C1I1 for conventional RC
alternative means the final cost of construction including all the activities until the delivery of building
In modular alternatives PSM PCM and PTM includes the module fabrication in off-site plants
transportation installation on-site and final finishing of building after the assembly phase All
indicators are based on ldquoAustralian dollarsrdquo units (AUSD) because of the recourse quantities that was
used for this study which will be discussed more later Second indicator which is the costs stability
(R1C1R2) was chosen because of the common off-site production economic advantage that is
stabilizing the costs for the projectrsquos budget because of high quality of product more repetition of
elements and more accurate supervision on activities which leads to less reworks and less extra costs
etc
Total project schedule R2C1I1 is the first indicator for time requirement which include the
amount of time to fabricate transport and final assembly of the modules on-site in modular
alternatives and the final schedule of the conventional project during construction activities until the
delivery of the building which all are based on ldquodaysrdquo it was mentioned earlier that in off-site
production the project schedule can be estimated and controlled more adequately so that second
indicator which is time stability R2C1I2 was introduced to the study
Environmental requirement was studied in various features as it said before in 7 criteria which
shows the complexity of comparisons between alternatives First indicator is the Energy utilized during
construction R3C1I1 based on ldquoMJrdquo units Solid Waste R3C2I1 is the only indicator for Waste
generation criteria that focuses on the amount () of waste which was produced during
constructionfabrication activities in all four activities In material consumption criteria the total
amount of materials that was used for constructionfabrication of elements R3C3I1 is appointed as an
indicator to compare the benefits in each alternative based on ldquoKgrdquo Noise reduction in off-site
construction is another benefit that it has and to discuss this fact among the alternatives Average A-
weighted equivalent sound level of each construction equipment R3C4I1 based on ldquodBrdquo units was
focused on Greenhouse gas emission among alternatives was measured in CO2 that was produced
during constructionfabrication activities R3C5I1 based on ldquoKGrdquo units Two indicators were introduced
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
67 | P a g e
for recycle criteria between four alternatives recyclability or possibility of recycling of elements
R3C6I1 and Re-use of elements (Products) in projects R3C6I2 based on Percentages Embodied energy
was the last criteria which was focused on with two indicators Embodied energy used R3C7I1 in ldquoGjrdquo
units and Embodied energy saved by re-use of elements in percentages among alternatives
For safety measurements two indicators were selected for two criteria which are injury risk
level R4C1I1 for injury risk criteria and Protection level R4C2I1 for protection from nature causes both
in a qualitative unit
Job stability R5C1I1 for comparing the job status in terms of security of jobs among two
methods and new job creation R5C1I2 to analyse the possibility of providing new job positions which
is crucial in these era in construction industry were chosen in qualitative unit
The last criteria in social requirement which is quality of projects was presented with one
indicator of quality satisfaction of client R5C2I1 in qualitative unit to compare the clientrsquos satisfaction
level between alternatives Table 4 1 - Requirement tree with all indicators which considered for decision making process
Requirements Criteria Indicators
(R1) Economic (R1C1) Project Cost (R1C1I1) Total Project Cost
(R1C1I2) Cost Stability
(R2) Time (R2C1) Project schedule (R2C1I1) Total Project Schedule
(R2C1I2) Time Stability
(R3) Environmental
(R3C1) Energy Consumption (R3C1I1) Energy Utilized during construction
(R3C2) Waste Generation (R3C2I1) Solid Waste
(R3C3) Material Consumption (R3C3I1) Material Consumed in project
(R3C4) Noise Pollution (R3C4I1) Average A-weighted Equivalent sound Level of each instrument
(R3C5) Greenhouse Gas Emission (R3C5I1) Co2 in constructionfabrication
(R3C6) Recycle (R3C6I1) Recyclability of Elements
(R3C6I2) Re-use of elements
(R3C7) Embodied Energy (R3C7I1) Embodied Energy Used
(R3C7I2) Embodied Energy Saved
(R4) Safety (R4C1) Injury Risks (R4C1I1) Injury Risk Level
(R4C2) Protection from Nature Causes (R4C2I1) Protection Level
(R5) Social (R5C1) Job Status
(R5C1I1) Job Stability
(R5C1I2) New Job Creation
(R5C2) Quality (R5C2I1) Quality Satisfaction of Client
The input data for indicators are categorized in 4 types direct data calculated data estimated
data and qualitative data The reason for not having only direct data is the lack of enough literature
researches on this subject and in some cases the data were published two months before the date of
this study The variety of alternatives which is the first time that a study is going to analyse 3 modular
alternatives and a traditional method added difficulty to find useful data to do the decision making
reliable Moreover 5 articles were used for finding the correct data which each of them focused on
different alternatives The orientation of this study is the Cleaner Production journal by professor
Hammad that was published in 2019 which was mentioned earlier The reason of this orientation is
that most of the data came from this article and is more updated than the others
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
68 | P a g e
bull Direct Data
The direct data were the information that was related precisely to the alternatives without
any needs to change For instance the cost of the construction in Hammadrsquos article which can be used
without any changes The green parts on the Table 42 shows the direct data which are related to the
Hammadrsquos article Table 4 2 - PSM modules data with direct data shown in green parts which no changes are needed to be done on them
bull Calculated Data
In many indicators because of lack of existence in directly related data for alternatives a sort
of calculations were needed to change the data from other articles that related to alternatives that
are not focused in main case (Hammadrsquos article) to actual data based on the area of main article by
using accurate coefficients and ratios For instance in Hammadrsquos article CO2 was not estimated for
Prefabricated Steel Modules (PSM) alternative but Ayersquos CO2 data which is for total area of 3943m2
with 63 apartments each area of 628 m2 (close to 625 m2 area of Hammadrsquos granny flat) was used
by dividing on 63 apartments units so that results 54079 kg of CO2 for steel modular equivalent for
main case The yellow parts show the calculated data for indicators
3407000119896119892 1198881199002 divide 63 119906119899119894119905119904 (6251198982) = 54079119896119892 1198881199002 for steel modules in main case
Table 4 3 ndash PSM modules final data with yellow parts show the calculated data based on other studied
bull Estimated Data
Third type of input data were the necessary data which are not existed on any of literatures
of have to be estimated based on the qualitative information professional survey which have been
done before the decision making process (Chapter 3) and researcherrsquos opinions Fortunately in many
areas the data could be applied on other alternatives because of similarity of activities off-site and
onsite For instance for PCM alternative the noise and Injury risk level are approximately the same
the indicators of PSM case that have mentioned in Hammadrsquos article which are shown in green parts
in Table 42 because of similarity of off and on site activities during construction
The blue parts are the estimated data that were considered for PCM alternative based on
mentioned resources For instance the time indicator can be predicted 24 days few days more the
steel modules which is around 22 days because of the fact that concrete modules are heavier than
steel ones and has more complexity in structure for being produced that adds difficulties on
transportation process which leads to more delays on the schedule Table 4 4 - PCM data with estimated data (blue) Calculated data (yellow)
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
69 | P a g e
bull Qualitative Data
This data was added because of two reasons first the lack of existence of direct data on
literatures and improve the literatures background on this subject and secondly to have more
influence from variety of benefits that modular construction has on the decision making process
Numbers of literatures insisted on advantages that can affect the decision making but did not
included on their data analyses at the end and this research decided to include these data and see
that how much functional can be in the decision making between alternatives in point of project
management view For instance cost stability which is better coordinated in off-site construction and
can be considered as an advantage to the decision making is not included in the literatures during
analysis and in this study is a vital factor for the economic criteria In order to add this indicator a
qualitative range was considered from 0 to 10 and four alternatives based on their functionality in cost
stability in project budget were compared to each other Traditional reinforced concrete building
which because of common reworks etc have less stability in final budget estimation On the other
side PSM and PTM which have the most repetition in manufacturing processes and ease of production
because of material type have the maximum cost stability of 9 out 10 among the others and PCM that
has less ease in production have less cost stability than other modular alternatives with 8 out of 10 Table 4 5 - Qualitative indicators
Final indicators
bull Prefabricated Steel Modules indicators (PSM)
As it mentioned before the direct data which are shown in green at table 46 do not need any
changes as they belong to the main case study while other indicators are still needed to be calculated
estimated and often considered qualitatively Aye case study have the closest data to the main case
study because of similarity of project type and dimensions so that the necessary indicators such as
material consumption waste generation percentage re-use amount and embodied energy indicators
can be calculated from this analytical study (For more information about indicators resources please
see Annex 1-A) Table 4 6 - First hand data over literature
A simple calculation is needed and that is dividing the CO2 emission Material
consumption and Embodied energy used amounts in Aye project on 63 apartment units with the
same area of 625 as main case in Hammads residential flat ldquoWaste amountrdquo ldquore-use of elementsrdquo
and ldquoembodied energy savedrdquo can be applied on the main case because of similarity of material
choices
IndicatorsAltertanives TRC PSM PCM PTM
Cost stability 6 9 8 9
Time stability 6 9 8 9
Recycleability of elements 3 8 7 9
Protection level 2 9 9 9
Job stability 5 8 8 8
New job creation 3 8 8 8
Quality satisfaction 5 9 8 9
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 482446 2131 645 163 8593
Balasbaneh 222580 9623
Akbarnezhad 97000 28 68768
Aye 3407000 871 5 50 56778 813
Units AUDMLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
70 | P a g e
Table 4 7 - Final Indicators with direct data (Green) and calculated data (Yellow)
bull Prefabricated Timber Modules indictors (PTM)
As it can be seen in table 48 there are no enough data over literature in many areas and due
to the necessities for this study a range of calculations and estimation have to be made based on the
similarity of projects among study cases and survey information Table 4 8 - First hand data over literature
Starting with Cost of the project which an ldquoestimationrdquo based on literature review information
and qualitative comparisons (John quale 2012) (Lu Aye2011) that is approximately 45000 AUD
because it proved that the cost of Timer modules is even cheaper than Steel Modules due to simplicity
of material choice and structure design The schedule of PTM building is shorter than the other
alternative because of numbers of reasons such as less weight of elements which can lead to faster
transportation loading and offload in assembly process on-site In addition the manufacturing lines
are simpler than other modular alternatives because of high repetitions and simplicity in design
For ldquocarbon emissionrdquo and ldquomaterial consumptionrdquo Aye project was used by diving on 63
apartment units which have the same area of 625 m2 as main case In terms of ldquowaste generationrdquo a
unique article was used (by Doyoon 2008) which did a LCA study on Timber modular building and the
amount of wastematerial consumed was about 9 The Noise level and Injury risk can be applied
from other modular alternative because of similarity of construction activities and equipment used
for fabrication Energy utilized during construction of Timer modules have the minimum amount in
comparison with other alternatives because of simplicity of material choice and design enhancement
so that was estimated 80MJ which is slightly less than steel modules with 86 MJ
Re-use of elements in timber modular elements was confirmed by survey among the
constructors over than 70 with a life span of 50 years Embodied Energy used was collected from
Aye case study dividing on 63 apartments units as same as other cases which equals to 65671 GJ
(Table 49) Table 4 9 - Final indicators with Calculated data (Yellow) and Estimated data (Blue)
bull Prefabricated Concrete Modules indicators (PCM)
The least focus on modular alternative was on Concrete Modules which is because of few uses
that this method has among the projects Balasbaneh study focused on a comparison between Steel
modules and Concrete modules in total project cost and LCA Table 4 10 - First hand data over literature
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 482446 2131 54079 138254 5 645 163 8593 50 9012 813
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury risk Energy utilized Re-use Embodied energy Emb saved
Aye 2500000 996 356 41373 691
Quale 13600
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 45000 20 39375 1580952 9 645 163 80 70 65671 691
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Balasbaneh 239380 8264
Units MLYR Days kg tons dB - MJ GJ
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
71 | P a g e
However the currency of this economic analysis is not as AUD (Australian Dollars) as the main
study Therefore to calculate the cost and CO2 footprint corresponding to main study case a ratio
was obtained between concrete modules amounts and steel modules in Balasbaneh study and then
multiplied to the steel modules quantities in Hammadrsquos main case and resulted project cost of
5188603 AUD and 46442 kg of CO2 emissions
Figure 4 10 - Balasbaneh Comparison in project cost (left) and CO2 (right) between PCM and PSM alternatives
239380 divide 222580 = 1075478 119862119900119904119905 119903119886119905119894119900 (Balasbaneh study case)
482446 times 1075478 = 5188603 119860119880119863 Total project cost of PCM
8264 divide 9623 = 085877 1198621198742 119903119886119905119894119900
54079 times 085877 = 46442 119896119892 CO2 of PCM
The time indicator was estimated based on steel modules but with this difference that
concrete modules weight more than steel ones so that puts pressure on the transportation and
assembly phases and causes delays in the schedule as a result 24 days was predicted to finish the
project
There is no available information on the literature with specific quantitative details however
based on the qualitative structural information prefabricated concrete modules PCM because of their
similarity of material choice to conventional model have a massive material use in comparison with
Steel and Timber alternatives so that an estimated total material consumed of 20000kg assigned for
this indicator (Aye 2011) (Balasbaneh 2020)
Waste generation have a higher ratio in this alternative because of material choices which
generate more waste than other modular alternatives With this fact in mind the waste ratio
considered slightly more than steel kind with 10 (Aye 2011)
Noise level and Injury risk can be applied from other types because of similarity of equipment
and construction activities in all three modular alternatives (Hammad 2019)
Energy utilized during construction in PCM Alternative can be estimated more than steel ones
because of types of materials used in these modules and their high weight with value of 90MJ (Aye
2011)
The structural elements are ldquonotrdquo built in material which have a high recyclability potential so
that decreases the Re-use ratio to 20 approximately in comparison with other modular alternatives
(Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
72 | P a g e
Embodied energy used amount and its potential saving have the minimum value in a
qualitative comparison with other alternatives which respectively values of 800GJ and 60 were
estimated for them (Aye 2011) Table 4 11 - Final indicators for PCM
bull Traditional Reinforced Concrete (TRC) final indicators
The highest focus over the literature is to make a comparison between one of the modular
options and a traditional method which results more availability for direct data for Traditional method
The main case study is not an exception with almost half of the value are available directly such as
Project cost Time Noise level Injury risk and Energy utilized during construction which are shown in
green at table 412 (Hammad 2019) Table 4 12 - TRC first-hand data over literatures
Nevertheless still there are values that must be calculated over literature Green gas emission
indicator and Embodied Energy used were calculated form Ayersquos case study by dividing the values on
63 apartment units which results 3620635kg Co2 emission and 6033 GJ of 625 m2 area as same as
main case study (Aye 2011) (Hammad 2019)
Material consumption have the same methodology as carbon footprint with final value of
626825kg which is massively higher from modular alternatives (Aye 2011) (Hammad 2019)
Waste generation was calculated qualitatively from a literature resource called ldquoModular
Construction for Multifamily Affordable Housingrdquo by WSP which acclaims that the conventional site-
built method produces around 25 times more construction waste (WSP 2018) Thus TRC waste
generation is more than 25 times of modular ones with the value of 15
Two values of Re-use and Embodied energy saved by Re-use of elements were obtained from
Ayersquos case study respectively 22 and 322 (Aye 2011) Table 4 13 - Final indicators for TRC with direct data (green) and calculated data (yellow)
In general the table 414 shows the References and final indicator values that were used for decision
making process (Direct data are shown in Green Calculated data in yellow and estimated data in
blue)
Table 4 14 - Final Quantitative indicators used for decision making process
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 5188603 24 46442 20000 10 645 163 90 20 800 60
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Hammad 812298 6598 71 217 198
Akbarnejad 120000 67 84672
Aye 2281000 3949 22 38008 322
Units AUDMLYR Days kg tons dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
Final 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrences Cost Time CO2 Material Waste Noise Injury riskEnergy utilized Re-useEmbodied energyEmb saved
PSM 482446 2131 54079 138254 5 645 163 8593 50 9012 813
PTM 45000 20 39375 1580952 9 645 163 80 70 65671 691
PCM 5188603 24 46442 20000 10 645 163 90 20 800 60
TRC 812298 6598 3620635 626825 15 71 217 198 22 6033 322
Units AUD Days kg kg dB - MJ GJ
Refrence Ham Aye Balas Hammad Balas Aye Aye Doyoon WSP Aye Hammad Hammad Hammad Aye Aye Aye
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
73 | P a g e
Weights
The Weights (Pesos in MIVES) which are one of the most important factors in decision making
process have be assigned on the data in a way that the priority of each section in terms of efficiency
and importance can decide which value will have among the others AHP method was used to assign
weights on the data In AHP you get the weights through the subjective importance of each element
with respect to the others (Alejandro Josa 2012)
bull Weights of requirments
The importance of requirmenets was assumed based on proffessional survey among
constructors architects sales agents and clients in order to know the demands of market and make
the decision rely on what market expects from a innovative method According to the survey time
reduction is the first priority for choosing the modular methods by constructors and future clients so
than acheived 30 of weight Economic issues came after the time factor because of unconsistency
between responds about cost saving on the budget or offseting the expenses gap by tarnsportation
extra costs on the project Economic requirement has 27 of weight In some regions the priority of
choosing an innovative method are environmental emissions waste generation and recycleability of
products Therefore environmental requirement came after the economic one with 25 of weight
As it mentioned before Social and safety advantages are included in this decision making
process with respectly weights of 13 and 5 because of their less priorities among clients and market
players Table 4 15 - Requirement weights
Requirement Economic Time Environmental Safety Social
Weights 27 30 25 13 5
bull Weights of criteria
In cost and time of project which are single criteria have 100 of weights However for
instance in environmental and AHP method must be used to assign the weights based on the
importance in an environmental consideration The amount of emission that construction activities
can produce and the amount of negative effect on the global environment have been considered for
AHP method in weight assignment process Energy consumption and material consumption have the
priority to consider in LFA analysis because the consumption of primary resources have to be
minimized in a project at the first step and then the emission have to be reduced by changing the
processes etc Finally the ability to re-use and recycle and elements must be improved (Mohammad
Kamali 2017) (John Quale 2012) (Marta Gangolells 2014) Therefore Energy Consumption and
Material consumption have the most weight of 17 Embodied energy with 16 and waste generation
Greenhouse Gas emission and Recycle achieved 15 of weight At last noise Pollution took the least
priority of weights with 5 Table 4 16 - Weights of criteria
bull Weights of Indicators
Both of Economic and Time indicators divided to two sub-categories project cost and time and
their stability ratios with 80 and 20 weights by AHP method
Criteria that are single indicator obviously have 100 of weights However there are two
indicators in recycle criteria Recyclability and Re-use of elements with 40 and 60 weight
respectively Moreover Embodied Energy have is divided to Embodied energy used which is more
CriteriaEnergy
consumption
Waste
generation
Material
Consumption
Noise
pollution
Greenhouse
gas emissionRecycle
Embodied
energy
Weights 17 15 17 5 15 15 16
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
74 | P a g e
important than the other that is saving in embodied energy by re-use because as it mentioned before
in the first place the use have to be minimized and then actions such as re-use of elements have to be
done 70 of weight for Embodied energy use and 30 for Saved Embodied energy are assigned Job
stability and New job creation with weights of 50 each are the Job status indicators (Figure 411)
Figure 4 11 - Weights assigned on the Requirements criteria and Indicators in MIVES software
Value function play an important role on deciding which comparative final value can each
indicator have among the other indicators for each alternative To evaluate the sustainability index
(Is) of each alternative solution value functions assigned and were used (Alarcon et al 2011) The
generic form of a value function is represented by Table 417 which allows to assess the sustainability
(satisfaction) associated with each indicator by transforming the physical units to a dimensionless
value between 00 and 10
Equation 4 1 - Functionality of value function elements
In Eq (41) B is the value of indicator(Iind) for Xmin Xmin is the minimum abscissa value in the
indicator interval assessed X is the abscissa value for the indicator assessed Pi is a shape factor which
defines whether the curve is concave (Pi lt 1) convex (Pi gt 1) linear (Pi = 1) or S-shaped (Pi gt 1) (see
figure 412) Ci approximates the abscissa at the inflexion point Ki tends towards (Iind) at the inflexion
point B the factor that prevents the function from exceeding the range (0 1) is obtained by Eq (42)
Xmax being the abscissa value of the indicator that gives a response value of 1 for increasing value
functions
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
75 | P a g e
Equation 4 2 - B value equation
Figure 4 12 - Possible forms of the value function
Due to the lack of existence of resources for assigning the specific value functions for modular
alternatives some hypotheses that can increase the feasibility and sustainability of project were
considered for the shape P K and C values to select the best form of abacus
In the other side maximum and minimum satisfaction points were selected on the
expectations of a project management view For instance in total project cost indicator case
minimum satisfaction point is 82000 AUD that is slightly more than the traditional reinforced concrete
alternative project cost (812298 AUD) because of the fact that those alternatives should be
considered as a reasonable options which can make saving in final budget Moreover the same rule
can be applied for maximum satisfaction point which is close to the Timber Modular alternative (45000
AUD) to minimize the final budget as much as possible The shape of the abacus was selected as
Convex shape (Convexa in MIVES) because even the least economic saving that an alternative can
achieve have a positive effect on the satisfaction of project and can be given any positive points in a
scale of ldquo0 to 10rdquo But the more the curve closes to the traditional alternative budget the les
satisfaction it can receive (Figure 413)
Figure 4 13 - Value function for total project cost in MIVES
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
76 | P a g e
The following Table 417 includes the value functions which were used for the rest of the
indicators Table 4 17 - Value function for indicators in MIVES
Data analysis
Indicators Values
Indicator data were translated to general normalized values shown in Table 418 amp 419 based
on the given value functions that earlier assigned This step is crucial for next analyses which will be
done to result the criteria and requirement values which lead to sustainability Indexes that can take
the multi-criteria decision As it can be seen these values have the same range of 0 to 1 so that can be
compared in with a common unit Comparisons are obvious in this level because of single value
orientation of each indicator however on following analysis there will be multi-criteria comparisons
which can achieve useful data for future decision-making process Table 4 18 - Indicators normalized values
Table 4 19 ndash Indicator normalized values
Indicators Lower limit Upper limit Max satisfaction Min satisfaction P K C Shape
Total Project Cost 30000 90000 43000 82000 05 05 79900 Concave
Cost stability 0 10 10 5 05 05 55 Concave
Total Project Time 20 75 20 68 05 05 632 Concave
Time stability 0 10 10 5 05 05 55 Concave
Energy Utilized 75 220 80 205 05 05 1925 Concave
Solid Waste 0 100 0 18 08 05 162 Concave
Material Consum 10000 70000 12000 63000 05 05 57900 Concave
Noise Level 58 78 62 72 05 05 71 Concave
CO2 32000 60000 32000 55000 05 05 52700 Concave
Recyclability 0 10 10 0 05 05 1 Concave
Re-use 0 100 60 0 05 05 20 Concave
Embodied energy 600 950 600 915 05 05 8835 Concave
Embodied saved 0 100 90 30 05 05 36 Concave
Injury risk 0 4 155 22 05 05 2135 Concave
Protection level 0 10 10 0 1 001 1 Lineal
Job stability 0 10 9 4 1 001 45 Lineal
New job creation 0 10 10 0 05 05 5 Concave
Quality Satisfaction 0 10 10 0 1 001 5 Lineal
R1C1I1 R1C1I2 R2C1I1 R2C1I2 R3C1I1 R3C2I1 R3C3I1 R3C4I1 R3C5I1
TRC 016 051 024 051 027 029 01 034 092
PSM 094 092 098 092 098 082 099 088 023
PCM 09 081 097 081 097 059 093 088 065
PTM 098 092 1 092 1 064 097 088 085
R3C6I1 R3C6I2 R3C7I1 R3C7I2 R4C1I1 R4C2I1 R5C1I1 R5C1I2 R5C2I1
TRC 073 026 1 024 024 021 02 063 05
PSM 095 094 023 095 094 09 08 092 09
PCM 092 068 064 077 094 09 08 092 08
PTM 098 084 092 085 094 09 08 092 09
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
77 | P a g e
Criteria Values
MIVES analysed each criterion by single or multi-indicator normalized values and resulted
values with a same range of 0 to 1 for following comparisons Table 4 20 - Criteria normalized values
Table 4 21 - Criteria normalized values
To begin with Project Cost (R1C1) criteria values shows that Almost three modular
alternatives performed 3 times more than the traditional method positively caused by hugely less total
project cost (R1C1I1) and great cost stability (R1C1I2) in project final budget The minimum value
belongs to PTM with 097 and slightly more than PSM and PCM is the next alternative with a value of
088 and at last TRC with 023 (Figure 414)
Figure 4 14 - Criteria normalized values
The comparison between modular alternatives in terms of which one can save time on the
schedule is close and it can be said that all three can make the project executed more than 3 times
shorter than traditional approach Timber steel and concrete options with respectively 098 097 and
094 values were compared to the conventional concrete method with 029 value (Figure 415)
R1C1 R2C1 R3C1 R3C2 R3C3 R3C4
TRC 023 029 028 029 009 032
PSM 094 097 099 083 099 088
PCM 088 094 096 059 094 088
PTM 097 098 101 064 096 088
R3C5 R3C6 R3C7 R4C1 R4C2 R5C1 R5C2
TRC 091 045 083 024 021 040 052
PSM 024 096 048 095 090 088 092
PCM 064 077 072 095 090 088 080
PTM 085 091 096 095 090 088 092
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
78 | P a g e
Figure 4 15 - Project Schedule
ldquoEnergy saving potentialrdquo in modular methods are close to the maximum satisfaction point
with timber solution and steel modules while concrete option is on the chase with 096 While
Traditional alternative only have 28 of satisfaction level
ldquoWaste generationrdquo among the alternatives have a different attitude while traditional method
with value of 029 has the most ratio of material waste production modular alternatives are
performing better where steel option have the most reduction with value of 083 and follow to that
timber and concrete options respectively 064 and 054 values PCM alternative as it said before
because of similarity of material choice to TRC have the minimum performance among the other
three (Figure 416)
Figure 4 16 - Waste generation ratios
ldquoMaterial consumptionrdquo criteria are dominated by modular methods which have a high
satisfaction with over than 09 normalized values while TRC performance can be concerning for the
primary resources with 01 normalized value
Previously on this report the fact was mentioned that off-site construction can benefit the
environment with noise reduction during construction activities based on literatures and this study
confirms this advantage by 088 values of all three modular alternatives and 032 value of traditional
RC which is less than half of modular options
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
79 | P a g e
A highlight of this study is about the comparison of CO2 Emissions of alternatives during the
constructionfabrication activities which traditional method have the minimum contamination with a
value of 091 and follow to that Timber option with 085 which is close to the TRC method Later to
that Concrete modules have a value of 064 and the minimum satisfaction belongs to the steel
modules with 024 normalized value This result bring uncertainty to the fact that modular
construction can reduce the Greenhouse gas emission to 30 over the literature review
Figure 4 17 - CO2 Emission normalized values
This study shows that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options with a value of 096 because of the material choice
repetition in element manufacturing and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution have 091 value that can confirm the concept of
recyclability for wooden modules which was mentioned by participants in professional survey as well
Figure 4 18 - Recyclability and re-use potential of alternatives
There is a discussion about the amount of embodied energy used during the lifetime of each
alternative and the potential of future saving by re-use of elements in projects which effect the total
embodied energy consumption in construction
As the Figure 419 explains traditional method has the maximum satisfaction level in terms
of consumption while steel modules have the least satisfaction of life cycle embodied energy used of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
80 | P a g e
023 PTM have a better value of 091 which shows that Timber solution can be reliable among the
others
However this study resulted that the most re-use value belongs to steel option with 095
value that and other two timber and concrete modules respectively with 085 and 077 can
compensate the gap with traditional method that has only 024 Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction total value of 096 Later
traditional reinforced concrete method with 088 still proves its abilities over other two modular
alternatives
Figure 4 19 - Embodied energy consumption and saving potential by reuse
In terms of safety modular alternatives because of their off-site nature can provide a high
satisfaction level with values of 095 in injury risks for workers and 090 protection from nature causes
which confirms the theory of safety advantage of modular construction over traditional methods from
literature studies (Figure 420)
Figure 4 20 - Safety advantage of modular construction over traditional method
Social benefits which were mentioned in literature review section also had been examined in MIVES
system and the job stability and job creation in modular construction can benefits the construction
society in significant way among the regions that have employability ratio problem
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
81 | P a g e
Figure 4 21 - Social criteria
Requirement Values
After analysis on criteria functions general values of each requirement were related to
alternatives achieved which can examinate all four construction methods to know which option is
more suitable in terms of Economic time environmental safety and social issues
The Table 422 below demonstrates the Requirements normalized values for each alternative Table 4 22 - Requirement normalized values for four indicators
bull Economic and Time requirements
As the graph illustrates Modular methods have a significant performance in economic and
time terms with the maximum values of 097 and 094 in Time and 098 and o97 in Economic
requirement for Timber and then Steel modules-based methods respectively Traditional reinforced
concrete option showed a poor functionality in cost and time of project with minimum values of o29
and 023 in order (Figure 422)
Figure 4 22 - Time and Economic comparison between four alternatives by normalized values analysed by MIVES
Requirements Economic Time Environmental Safety Social
TRC 023 029 045 022 046
PSM 094 097 075 093 088
PCM 088 094 078 093 084
PTM 097 098 088 093 088
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
82 | P a g e
bull Environmental requirement
Generally all three modular approaches have beaten the traditional method with almost
double of normalized values in comparison
Despite the poor performance of steel modules in Greenhouse gas emissions and Embodied
Energy used in construction in total numbers proved that can provide the environmental demands
better than traditional option with a value of 075 which is third modular alternative in overall
Prefabricated Timber modules obtained the maximum value of 088 which claims not only
most economic option but environmentally friendly among other relatives and following to that
Concrete modules with value of 078 shows its liability to be chosen in case of need while the
traditional concrete method which includes most of the used materials n PCM but in a on-site plant
only can achieve a satisfaction value of 045 among the others (Figure 423)
Figure 4 23 - Environmental Comparison among modular approaches and traditional kind
bull Safety and social requirements
The dominance of Modular construction in safety and social requirements over conventional
option can be seen in Figure 424 which can raise the possibility of modular methods to be the best
decision over the traditional option to construct this residential project As it was mentioned before
these two criteria must be considered in any decision-making process because of their high
importance in construction industry
Figure 4 24 - Modular dominance in safety and social requirements over conventional option
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 4 Decision making process among modular and traditional alternatives with MIVES
83 | P a g e
Sustainability Values (Final decision)
Finally the sustainability Indexes can be obtained to claim which alternative will be decided
as the most sustainable option for the main studyrsquos project to be build The needs of market such as
short project schedule cheaper budget reduction in environment emissions and ability to
recyclereuse safety measures and social benefits put effects on this decision as previously
mentioned
Table 423 explains that Prefabricated Timber Modules (PTM) is most sustainable alternative
among the other with a perfect normalized value of 094This could be because of its shorter schedule
of construction lowest total budget and excellency in environmental performance among the other
alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative Table 4 23 - SI (Sustainability Indexes related to four alternatives)
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This fact explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Figure 4 25 - Sustainability Index which makes the final decision among the alternatives
TRC PSM PCM PTM
SI 032 090 088 094
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
84 | P a g e
5 Conclusions Decision making process
To identify the advantages of modular construction in comparison with traditional method
literature review can be made and by analysing each criterion such as economic and environmental
criteria etc However to find out how much practical these benefits are in the market several trade-
offs must be done by professional tools such as project management software programs which can
take decisions based on the input data that receive MIVES software was used in this study to
examinate these benefits The resources for this type of studies are limited due to the lack of focus or
newfound nature of this subject and only five of them were selected because of their variety of their
criterion studies reliability and accuracy of data Requirements criteria indicators and weights that
were used in MIVES had been selected based on demands of market and professional opinions
received from the survey and availability of data over references After assigning the value functions
which are related to satisfaction level on each criterion (For instance cost reduction time saving and
minimization of emissions) normalized values were achieved that can be compared between
alternatives with range of 0 to 1
Conclusions and discussion
ECONOMIC ndash TIME discussion
bull Decision-making result
Generally all three modular alternatives have beaten the traditional method with almost
double of normalized values Modular methods had a significant performance in economic and time
terms with the maximum values in Time and Economic requirements for Timber and then Steel
modules Traditional reinforced concrete option showed a poor functionality in cost and time of
project with minimum values
Literature reviews information
These Results confirm the 50 of time saving in projectrsquos schedule (McKinsey amp Company
report 2019) and 20 of cost reduction on the budget which was mentioned also in numbers of
literatures
Professional survey confirmation
In addition the claims from professional participants in survey about the 50 cost reduction
due to the added value of every hour of work in comparison with traditional stick and build on-site
method can be approved even far more those expectations
ENVIRONMENTAL discussion
bull Recyclability and re-use potential
This study showed that the prefabricated steel modules have the highest potential of recycle
and re-sue in the projects among the other options because of the material choice repetition of
elements in manufacturing line and long lifetime of structural parts which were mentioned in
literatures Slightly less than PSM Timber solution can confirm the concept of recyclability for wooden
modules which was mentioned by participants in professional survey as well
bull Embodied energy used and saving by re-use
There is a discussion over the literature and survey participants about the amount of
embodied energy used during the lifetime of each alternative and the potential of future saving by re-
use of elements in projects which effect the total embodied energy consumption in construction
where one of the companies acclaims that ldquoour homes are not positive in energy consumption
aspectrdquo Traditional method has the maximum satisfaction level in terms of consumption while steel
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
85 | P a g e
modules have the least satisfaction of life cycle embodied energy used PTM have a better value of
091 which shows that Timber solution can be reliable among the others However this study resulted
that the most re-use value belongs to steel option and other two timber and concrete modules
respectively can compensate the gap with traditional method Totally PTM was able to offset the
difference by the re-use potential and achieve the most satisfaction Later traditional reinforced
concrete method still proves its abilities over other two modular alternatives
bull Greenhouse gas emission
Despite the poor performance of steel modules (PSM) in Greenhouse gas emissions that bring
uncertainty to the fact that modular construction can reduce the Greenhouse gas emission to 30
over the literature review and Embodied Energy used in construction proved that can provide the
environmental demands better than traditional option which is third modular alternative in overall
comparison
bull Most environmentally friendly alternative
Prefabricated Timber modules obtained the maximum value which achieves not only most
economic option but environmentally friendly among other relatives Following to that Concrete
modules shows its liability to be chosen in case of need while the traditional concrete method which
includes most of the used materials of PCM but in an on-site plant only can achieve the minimum
value
Comparison with literature review information and survey outputs
This comparison explains the truth about the concept of being environmentally friendly about
modular construction that have been mentioned in various scientific articles (McKinsey amp Company
report 2019) (M Kamali 2016) and the survey results which confirmed the concept in real cases at
the market over years of experience
SAFETY AND SOCIAL dominance by modular methods
The dominance of Modular construction in safety and social requirements over conventional
option was resulted which can raise the possibility of modular methods to be the best decision over
the traditional option to construct this residential project As it was mentioned before these two
criteria must be considered in any decision-making process because of their high importance in
construction industry Social benefits which were mentioned in literature review section also had been
examined in MIVES system and the job stability and job creation in modular construction can benefits
the construction society in significant way among the regions that have employability ratio problem
FINAL DECISION MAKING BASED ON SUSTAIABLITY INDEXES
Prefabricated Timber Modules (PTM) is most sustainable alternative among the other with a
perfect normalized value of 094This could be because of its shorter schedule of construction lowest
total budget and excellency in environmental performance among the other alternatives
The second-best alternative is Prefabricated Steel modular method which achieved a value of
09 that is slightly less than the PTM option In couple areas Steel modules had poor results even less
than traditional method however due to priorities of market and industry this alternative was able
to compensate its gaps and beat the conventional option and other PCM relative
Prefabricated concrete acclaimed the sustainability value of 088 which is more than double
the traditional of its kind (032) which shows the superior nature of off-site construction even in closest
material choice to the conventional construction methods This result explains the fact that materials
enhancement is not the only factor that can improve the sustainability of a method but off-site plant
fabrication standardization of elements use of automation and applying the concept of repetition on
production line can make a significant impact on sustainability performance
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 5 Conclusions amp future studies
86 | P a g e
Effective external factors on decision
The decision was made for the best alternative in terms of sustainability for a specific
residential case located in Sydney Australia among three modular options and one traditional
method However there are factors which can affect the final decision obviously Such as the location
of the project which the availability of primary resources can change the or alternatives or number of
indicators The local market and their demands for specific products can be crucial for choosing the
best method which affect the priorities of weights Regulation of every regions as it was mentioned
before can change the project requirements and indicators
The type of the project was a residential building that has its own characteristics but for
instance a school or hospital project would demand a higher functionality and lifetime because of their
distinctive operation kind and evidentially can be considerable in decision-making process to the end
step Special project due to their unique requirements often do not consider all criterions For
instance emergency health stations demanded during the Virus pandemic period have their own
material choose design enhancement and priorities on requirements
Future studies
Due to novelty of this subject there are numbers of studies still remained without coverage
which might be studied in future
Decision making study on two real projects with the input data of professional
modular and traditional constructors
Due to the lack of information over literature there were so many elements that have been
estimated by hypothesis and survey information therefore it is crucial to find these data in order to
do a precise study with real numbers These data can be obtained by requests to industry players to
have access of real project details including budget schedule material consumptions etc By this
action the liability of the study can be improved and accurate results can be achieved Thus a
decision-making process can be done to find out which alternative can be more sustainable
Technological studies about the production line of a modular off-site plant by factory
and on-site visits
There are still uncertainties about the status of use of automation productivity rate etc which
have to be analysed closely Modular construction was suggested as an example of industrialization in
construction industry to improve the productivity rate but corresponding to past survey the majority
of constructors are not benefiting from automation in their production lines and assembly processes
A study is needed on different phases of a project that have to be monitored and analysed scientifically
in order to find challenges errors and possible solutions to make this method even more sustainable
A survey about challenges in modular construction and its possible solutions to find
adequate solutions
Challenges have to focused more on this method because its players are still suffering from
the incompatibility of construction industry and the projectrsquos old conditions with innovative solutions
Series of interviews with experts factory visits etc have to be done to hear the voices of them and
then researchers to find solutions to update the industry and help them for growth
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
87 | P a g e
Recommendations
Cooperation between industrial players and scientific researchers in offsite
construction
Numbers of contrasts where found in the data and results among literatures professional
participants of survey and the decision-making study which shows a poor status of cooperation
between scientific researchers and professional players in the construction industry It is obvious that
the real data from the constructors designers etc in real projects are more reliable than scientific
estimation which in this case were based on BIM models and approximate calculations without any
interruption effects of common challenges in industry There were few participants who did not want
to share their project details in public or even education purposes or in a case one of the most
innovative players in modular industry responded their lack of available time to respond the survey
by direct email These attitudes can increase the gap between two vital elements for improvement
which are science and industry in construction society and to reduce it cooperation must be increased
specially in off-site society
Education about industrialization in construction and its alternatives
The idea of lack of education among engineers and architects who enter the professional
society about off-site construction methods was proved by the collected information from survey
participants which can cause problems in the projectrsquos design coordination and execution processes
These series of errors must be resolved by updating the education resources about innovative
methods such as off-site construction industrialization in construction concept rather than traditional
on-site methods that still occupy most of the educational courses these actions can improve the
common challenges in construction industry such as productivity problem and sustainability rate by
encouraging the researchers even far beyond the boundaries of investigations and make the way
possible to find more innovative solutions such as robotic fabrication 3D concrete printing etc
Establishing international and regional adequate codes
Use of automation is suggested by the researchers and industry players to raise the
productivity and sustainability in construction as the other industries which resulted positively
However constructors and manufacturers are suffering from a lack of exitance of international united
codding for their production line and boundaries and uncertainties by local regulations
To resolve these issues participants addressed an international code similar to what on-site
traditional methods have which the responsibility of creation of these codes are on the shoulders of
researchers and professional experts with a mutual partnership that is only possible with cooperation
of industry with science as it mentioned before
Synchronizing the contract conditions with modular construction conditions
There are numbers of problems in terms of contract conditions such as misunderstanding by
final client who is the end home buyer who ldquobelieves the factory to be the builder and the actual
independent builder to be a sales agent for the factoryrdquo one of the participants mentioned A
recommended solution for this problem is to define the relationships between the participants of
projects their responsibilities For instance requiring the builders customer to sign a disclosure
acknowledgement from that describes the relationship in detail In addition there is a lack of quality
partners on site The problem starts when on-site participants realize the advantages of modular
construction they tend to increase their prices for services which can increase the final prices of
project Another challenge which modular projects can face is the lack of delivery of project on agreed
time with an unacceptable quality of on-site execution The professionals answered that the
Modular Construction potential advantages and common challenges | Masoud Veiskarami Chapter 6 Recommendations
88 | P a g e
responsibility of ensuring that the work is done properly belongs to the builder which any ldquodelays in
this can result in postponed transport of product and interest through demurrage chargesrdquo
These problems must be solved by defining unique types of contracts that are adapted with
the off-stie construction nature and be obeyed by all the participants globally
Education about modular construction among publicmarket and advertisements on
its potential advantages in social media etc
The only value that the market considers choosing modular method over traditional
construction is to be cheaper while majority of people the media and even professional engineers do
not understand the capabilities of modular construction Many people continue to confuse this form
of construction with HUD on frame products Another wrong perception that the publicmarket
believes is that the prefabrication methods limits the design options while some players believe that
the reverse is the case Therefore by using one of the main advantages of modular construction which
is shorter schedule the market can be dominated by modular projects and the more cases they
deliver the more recognised this method would be among the public and at the end the superior
nature of modular approach can be proved Another solution is a form of cooperation between
builders manufacturers architects and engineers to educate the public by national entities such as
Modular Home Builders Association Many of these wrong perception and misunderstandings can be
clarified by well-organized advertisements about several advantages that modular construction have
in comparison with conventional methods
Changes in financial strategies and adapting them with off-site construction nature
Financial assists which are crucial for kind of projects that are dependent to these aids are
not harmonized with modular project processes where there are argues that until the first deliveries
of elements to the site location and their assembly these aids will not be reachable This issue creates
pressure on cash flow of project where bank finance is involved Changes in contract conditions and
education for financial supporters are recommended solutions to improve the partnerships in
projects
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
89 | P a g e
6 References 1) Balasbaneh AT Ramli MZ A comparative life cycle assessment (LCA) of concrete and
steel-prefabricated prefinished volumetric construction structures in Malaysia Environ Sci
Pollute Res (2020) httpsdoiorg101007s11356-020-10141-3
2) Doran D and Giannakis M (2011) An examination of a modular supply chain a
construction sector perspective Supply Chain Management Vol 16 No 4 pp 260-
270 httpsdoiorg10110813598541111139071
3) Lawson RM Ogden RG Bergin R 2012 Application of modular construction in high-rise
buildings Journal of Architectural Engineering httpsdoi101061(ASCE)AE1943-
55680000057
4) Diez R et al (2007) lsquoAUTMOD3 The Integration of Design and Planning Tools for Automatic
Modular Constructionrsquo International Journal of Advanced Robotic Systems httpsdoi
1057725671
5) Lee J Park M Lee H ampamp Hyun H (2019) Classification of Modular Building
Construction Projects Based on Schedule-Driven Approach Journal of Construction
Engineering and Management 145(5) 04019031 httpsdoi101061(asce)co1943-
78620001656
6) Barbosa F Woetzel J Mischke J Ribeirinho M Sridhar M Parsons M Brown S
(2018 July 09) Reinventing construction through a productivity revolution Retrieved
September 28 2020 from httpswwwmckinseycomindustriescapital-projects-and-
infrastructureour-insightsreinventing-construction-through-a-productivity-revolution
7) Quale J Eckelman MJ Williams KW Sloditskie G and Zimmerman JB (2012)
Construction Matters Comparing Environmental Impacts of Building Modular and
Conventional Homes in the United States Journal of Industrial Ecology 16 243-253
httpsdoi101111j1530-9290201100424x
8) Horwitz-Bennett Barbara (2020) Rising to the challenge sl Modular Building Institute
(MBI)
9) Lu N amp Korman TM (2010) Implementation of Building Information Modeling (BIM) in
Modular Construction Benefits and Challenges
10) Institute Modular Building 2019 Permanent Modular Construction Canada Modular
Building Institute
11) Josa A (2012) Introduccioacuten a MIVES y el anaacutelisis multicriterio Jornada sobre la Importancia
de un meacutetodo para la toma de decisiones modelo MIVES para una ingenieriacutea sostenible
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
90 | P a g e
12) Aye L Ngo T Crawford R H Gammampila R amp Mendis P (2012) Life cycle greenhouse
gas emissions and energy analysis of prefabricated reusable building modules Energy and
buildings 47 159-168
13) Kamali M amp Hewage K (2016) Life cycle performance of modular buildings A critical
review Renewable and sustainable energy reviews 62 1171-1183
14) Lawson M Ogden R Goodier C (2014) Design in Modular Construction London CRC
Press httpsdoiorg101201b16607
15) Generalova E M Generalov V P amp Kuznetsova A A (2016) Modular buildings in modern
construction Procedia engineering 153 167-172
16) Thompson J (2019) Modular Construction A Solution to Affordable Housing Challenges
Cornell Real Estate Review 17(1) 21
17) Modular construction for multifamily affordable housing (2018) WSP
httpscdnymawscomwwwnibsorgresourceresmgrosccepa-modular-construction-
forpdf
18) Hammad A W A amp Akbarnezhad A (2017) Modular vs conventional construction a
multi-criteria framework approach In ISARC Proceedings of the International Symposium on
Automation and Robotics in Construction (Vol 34) IAARC Publications
19) Ferdous W Bai Y Ngo T D Manalo A amp Mendis P (2019) New advancements
challenges and opportunities of multi-storey modular buildingsndashA state-of-the-art review
Engineering Structures 183 883-893
20) Bertram N Fuchs S Mischke J Palter R Strube G amp Woetzel J (2019) Modular
construction From projects to products McKinsey amp Company Capital Projects amp
Infrastructure 1-34
21) Hsu P Y Aurisicchio M amp Angeloudis P (2020) Optimal logistics planning for modular
construction using multi-stage stochastic programming Transportation Research Procedia
46 245-252
22) Rausch C Nahangi M Perreault M Haas C T amp West J (2017) Optimum assembly
planning for modular construction components Journal of computing in civil engineering
31(1) 04016039
23) Connor G Jones C E amp Finney S J (2014) Easing future low voltage congestion with an
AC chopper voltage regulator httpsdoi 101061(ASCE)CO1943-78620001001
24) Ahn Y H amp Kim K T (2014) Sustainability in modular design and construction a case
study of lsquoThe Stackrsquo International Journal of Sustainable Building Technology and Urban
Development 5(4) 250-259
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
91 | P a g e
25) Gunawardena D Mendis P Ngo D Aye L amp Alfano J (2014) Sustainable prefabricated
modular buildings httpsdoi 10131402148473920
26) Olearczyk J Al-Hussein M Bouferguene A amp Telyas A (2009) Virtual construction
automation for modular assembly operations In Construction Research Congress 2009
Building a Sustainable Future (pp 406-415)
27) Woźniak-Szpakiewicz E (2016) EU migrant crisis and increasing demand for modular
construction modular social housing complex for refugees in Munich In Back to the Sense
of the City International Monograph Book (pp 921-931) Centre de Poliacutetica de Sogravel i
Valoracions
28) Wunderlich-Malec 2019 The Modular Solution to Reduce Total Construction Costs
httpswwwslidesharenetJoelGil2wuderlich-malec-engineering-modular-construction
29) HAMMAD AWA AKBARNEZHAD A WU P WANG X and HADDAD A 2019 Building
information modelling-based framework to contrast conventional and modular construction
methods through selected sustainability factors Journal of Cleaner Production [en liacutenea] vol
228 pp 1264ndash1281 ISSN 0959-6526 DOI httpsdoiorg101016jjclepro201904150
Disponible en httpwwwsciencedirectcomsciencearticlepiiS0959652619312296
30) HONG J SHEN GQ LI Z ZHANG B and ZHANG W 2018 Barriers to promoting
prefabricated construction in China A costndashbenefit analysis Journal of Cleaner Production
[en liacutenea] vol 172 pp 649ndash660 ISSN 0959-6526 DOI
httpsdoiorg101016jjclepro201710171 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS0959652617324782
31) LOPEZ D and FROESE TM 2016 Analysis of Costs and Benefits of Panelized and Modular
Prefabricated Homes Procedia Engineering [en liacutenea] vol 145 pp 1291ndash1297 ISSN 1877-
7058 DOI httpsdoiorg101016jproeng201604166 Disponible en
httpwwwsciencedirectcomsciencearticlepiiS1877705816301734
32) NEELAMKAVIL J 2009 Automation in the Prefab and Modular Construction Industry [en
liacutenea] Sl sn DOI 1022260ISARC20090018 Disponible en
httpwwwiaarcorgpublicationsproceedings_of_the_26th_isarcautomation_in_the_pref
ab_and_modular_construction_industryhtml
33) SANTIAGO M ALBERTO J MARIA NJ and PATRICIA G 2008 Building industrialization
robotized assembly of modular products En M ONORI (ed) Assembly Automation [en
liacutenea] vol 28 no 2 pp 134ndash142 ISSN 0144-5154 DOI 10110801445150810863716
Disponible en httpsdoiorg10110801445150810863716
34) McGeorge D amp Zou P X (2012) Construction management new directions John Wiley amp
Sons
35) Fieldwire (2018) Why the Construction Industry Is Stuck in the Past
httpswwwfieldwirecomblogis-construction-stuck-in-the-1960s
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
92 | P a g e
36) Construction industry - Office for National Statistics (2019) ONS
httpswwwonsgovukbusinessindustryandtradeconstructionindustry
37) Timmer M P O Mahony M amp Van Ark B (2007) EU KLEMS growth and productivity
accounts an overview International Productivity Monitor 14 71
38) Smith A (2011 September 22) Agile and Lean for Construction SlideshareNet
httpswwwslidesharenetadrianlsmithagile-and-lean-for-construction-9384237
39) The massive opportunity of digitization in Engineering amp Construction (2019)
JourneyappsCom httpsjourneyappscomblogmassive-opportunity-digitization-
engineering
40) Tapscott D amp Tapscott A (2018) Blockchain Revolution How the Technology Behind
Bitcoin and Other Cryptocurrencies Is Changing the World (Reprint ed) Portfolio
41) Can Blockchain Fix the Construction Industryrsquos Productivity Problem (2018) Enstoa
httpsenstoacomblogcan-blockchain-fix-construction-industrys-productivity-problem
42) Itanola M (2019 June 5) Hey Quantity Surveyor is BIM going to take your job Blaze
Threads httpswwwblazethreadcomhey-quantity-surveyor
43) BIM Community (2017) Remodeling Construction Industry with Digitization BIM and
Reality Capture httpswwwbimcommunitycomnewsload563remodeling-
construction-industry-with-digitization-bim-and-reality-capture
44) Kolarevic B (2003) Digital production Architecture in the digital age design and
manufacturing 38-63
45) Labonnote N Roslashnnquist A Manum B amp Ruumlther P (2016) Additive construction State-
of-the-art challenges and opportunities Automation in construction 72 347-366
46) Kapoutsis A C Chatzichristofis S A Doitsidis L de Sousa J B Pinto J Braga J amp
Kosmatopoulos E B (2016) Real-time adaptive multi-robot exploration with application to
underwater map construction Autonomous robots 40(6) 987-1015
47) Khoshnevis B (2004) Automated construction by contour craftingmdashrelated robotics and
information technologies Automation in construction 13(1) 5-19
48) R Alice (2019) CRYSTAL PALACE SHOWER TALK httpsbloginoxstylecomencrystal-
palace
49) Eba (2014) HISTORY ldquoballoon framingrdquo the first prefabricated building system (US)
Architecture for the 99 httpslikemyplacewordpresscom20140214history-balloon-
framing-the-first-prefabricated-building-system-us
50) Peter Goumlssel Arnt Cobbers Oliver Jahn (2012) A Brief History of Prefab ArchitectureWeek
httpwwwarchitectureweekcom20121003design_1-1html
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
93 | P a g e
51) Merin G (2018) AD Classics Habitat 67 Safdie Architects ArchDaily
httpswwwarchdailycom404803ad-classics-habitat-67-moshe-safdie
52) Sveiven M (2018) AD Classics Nakagin Capsule Tower Kisho Kurokawa ArchDaily
httpswwwarchdailycom110745ad-classics-nakagin-capsule-tower-kisho-kurokawa
53) Modular Building Experience | Deluxe Modular (2020)
httpswwwdeluxemodularcomexperience
54) Applications | Modular Construction | Bathroom Pods (2020) Howick Ltd
httpswwwhowickltdcomapplicationsmodular-constructionbathroom-pods
55) Project types (2018) Panel built httpswwwpanelbuiltcomblogmodular-building-types
56) Mobile Mini Merger - WillScot (nd) Willscot httpswwwwillscotcomAboutMobile-
Mini-Merger
57) Teague L (2017) Urbantainer breaks down the negative stereotypes of modular building
Frameweb httpsframewebcomarticleurbantainer-breaks-down-the-negative-
stereotypes-of-modular-building
58) Modular construction (nd) SteelconstructionInfo
httpswwwsteelconstructioninfoModular_construction
59) Modular V (2020) What Is Modular Building Construction Your Ultimate Guide Vanguard
httpsvanguardmodularcomabout-modular
60) Permanent Modular Construction Annual Report 2019 | Modular Building Institute (2019)
MBI httpswwwmodularorgHtmlPageaspxname=pmc-2019-home
61) Modular Construction Foundation (2020) Triumph Modular
httpswwwtriumphmodularcomabout-triumphour-servicesconstruction-
managementfoundations
62) Weights and Dimensions (2020) ITF httpswwwitf-oecdorgweights-and-dimensions
63) Sajip J (2019) Modular Construction A Sustainable Building Method NY-Engineers
httpswwwny-engineerscomblogmodular-construction-a-sustainable-building-
methodWeights and Dimensions (2020 August 28) ITF httpswwwitf-oecdorgweights-
and-dimensions
64) Muresan F (2019) What is Modular Construction NY-Engineers httpswwwny-
engineerscomblogwhat-is-modular-construction
65) ADVANTAGES of using SurePods prefabricated modular bathroom pods (nd) SurePods
httpswwwsurepodscomspeed
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
94 | P a g e
66) EasyPads - The easy-to-use foundation system for modular buildings (2019 March 23)
EasyPads - Foundation System httpseasypadscouk
67) Honrubia M amp Mendonccedila A (2019 June 18) The Benefits of Reusable and Modular
Constructions Ennomotive httpswwwennomotivecomreusable-modular-
constructions
68) Cosentino (2020) Discover Cosentino and all the characteristics of its materials
httpswwwcosentinocom
69) Al-Hussein M Manrique J D amp Mah D (2009) North Ridge CO2 analysis report
comparison between modular and on-site construction University of Alberta Canada
70) Vickers H (2017) Modular construction 4 health and safety benefits Building 4 Education
httpsb4edcomArticlefour-health-and-safety-benefits-of-modular-construction
71) PRISM (2020) HGA and The Boldt Company build STAAT ModTM critical care units to
address the COVID-19 hospital bed shortage PRISM Modular construction 4 health and
safety benefits Building 4 Education httpsb4edcomArticlefour-health-and-safety-
benefits-of-modular-construction
72) Harrouk C (2020 September 28) Mayor of London Launches Housing Design App to
Transform Construction ArchDaily httpswwwarchdailycomauthorchristele-harrouk
73) Schoenborn J (2012) A case study approach to identifying the constraints and barriers to
design innovation for modular construction (Doctoral dissertation Virginia Tech)
74) Casas prefabricadas inHAUS (nd) servicio post-venta casa modular archivos InHAUS
httpscasasinhauscomfranceestagservicio-post-venta-casa-modular
75) Catalunya U U P (nd) MIVES mdash Departamento de Ingenieriacutea Civil y Ambiental mdash UPC
Universitat Politegravecnica de Catalunya UPC httpsdecaupceduesproyectosmives
76) Kim D (2008) Preliminary Life Cycle Analysis of Modular and Conventional Housing in
Benton Harbor MI (Doctoral dissertation)
77) Gangolells M Casals M Forcada N amp Macarulla M (2014) Analysis of the
implementation of effective waste management practices in construction projects and sites
Resources conservation and recycling 93 99-111
78) Alarcon B Aguado A Manga R amp Josa A (2010) A Value Function for Assessing
Sustainability Application to Industrial Buildings Sustainability 3(1) 35ndash50
httpsdoi103390su3010035
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
95 | P a g e
Anexo 1
a) Indicators resources
o Prefabricated Steel Modular (PSM)
Table A1 1 ndash Cost of project PSM (Hammad 2019)
Table A1 2 -Time of project PSM (Hammad 2019)
Table A1 3 - Energy utilized during construction (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
96 | P a g e
Figure A1 1 - Injury risks for workers (Hammad 2019)
Figure A1 2 - Average A-weighted equivalent sound level for construction methods (Hammad 2019)
Table A1 4 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
97 | P a g e
Figure A1 3 - Co2 amount (Aye 2011)
o Prefabricated Concrete Modular (PCM)
Figure A1 4 - Total project cost (Balasbaneh 2020)
Figure A1 5 - Date of the articlersquos publishment to find the currency exchange rate based on the date
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
98 | P a g e
Figure A1 6 - Currency converter MYR to AUD (wwwxecomcurrencyconverter)
Figure A1 7 - Greenhouse gas emission (Balasbaneh 2020)
o Prefabricated Timber Modular (PTM)
Figure A1 8 - Co2 emission (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
99 | P a g e
Table A1 5 - Material consumption amp Embodied energy used and Embodied energy saved amp Re-use amount (Aye 2011)
o Traditional Reinforced Concrete (TRC)
Table A1 6 6 - Projects cost (Hammad 2019)
Table A1 7 - Projects schedule (Hammad 2019
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
100 | P a g e
Table A1 8 - Energy utilised during construction process (Hammad 2019)
Figure A1 9 - Injury risks for workers (Hammad 2019)
Figure A1 10 - Noise level (Hammad 2019)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo A
101 | P a g e
Figure A1 11 - Greenhouse gas emission (Aye 2011)
Table A1 9 - Re-use amount Embodied energy used and Embodied energy saved (Aye 2011)
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
102 | P a g e
Anexo 2 1 Survey Q amp A
Q How many years of experience do your company have in modular construction
industry Table A2 1 - Professional experience of the company
Company Responses
A 10-15
B 10-15
C 20-30
D 20-30
E 30-50
Q How many years of experience do you have in the modulartraditional construction
and what is your job position Table A2 2 - Personal experience of participant
Company Responses
A 15 years
B 13 years sales manager
C 30 years of which the last 25 have been as design architect
D Quantity Surveyor
E 3 years Foreign Trade Manager
Q What types of modules your company products in terms of material Table A2 3 - Type of modules
Company Responses
A Wood Steel
B Wood
C Wood
D Wood
E Counter and Fibber cabins Steel
Q Which types of projects you did so far Table A2 4 - Type f projects
Company Responses
A Residential houses
B Schools Residential houses Commercial buildings
C Residential houses
D Schools Residential houses Hospital Commercial buildings
E Schools Residential houses hospital Commercial buildings
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
103 | P a g e
Q Num of employees num of factories and num of modules build Table A2 5 - Characteristics of production range
Company Responses
A 80 employees 1 factory 200 modsyear
B 130 1 490
C 15
D 50 Employees 2 factories 80 build
E 250 employees 2 factories 100000 m2 prefabricated 5000 containers 1000 cabinets TURKEY
Q What was your motivation to choosework in modular construction Table A2 6 - Motivation for doing modular construction
Company Responses
A High demands in market and lack of provide Innovation
B Economic profit
C Environmental benefits High demands in market and lack of provide Innovation Shorter construction schedule due to need Economic profit
D Shorter construction schedule due to need Innovation
E Economic profit
Q Do you have sup-contracts for your panels or they had built in your factories what
is the reason for this decision Table A2 7 - Panel production conditions
Company Responses A build our own
B PE design and approvals fire suppression design and installation ceramic tile Energy Star design and inspection are all subcontracted
C All built in house in our own workshop We have developed our own unique systems which are not available elsewhere
D build in factory - programme cost
E
EPS isolated panels are produced in our factories The other are being purchased from domestic market Standard is EPS isolation and its fixed costs are lower because of quantity The others are not standard investment in production is not feasible
Q What is the level of automation technologies you use in off-site and on-site
production and assembly Table A2 8 - Level of automation
Company Responses
A Extraordinarily little today investing in this heavily this year want to get to 80
B 20
C Off-site 60 on site 20
D 20
E 60
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
104 | P a g e
Q Does A modular project have a smaller number of labours Less wages of salary off-
site and on-site due to specialization of workforce Does the more value added in
each hour of work can compensate Table A2 9 - Laboral status
Company Responses
A Fewer labour hours and at less cost per hour 1 hour in the factory is equal to 4 on site
B Prefabricated systems-built modular construction generally has a smaller on-site labour force for a shorter period
C Labour similar but more efficient working off site
D Yes (less no of workers and wages) - no need for special work force
E -
Q Do you have any case of recycle and reuse the structuralnon-structural elements in
your projects Table A2 10 - Recycle and Re-use
Company Responses
A Yes
B Yes
C No
D No
E Yes
Q Do you upgrade the modules with other environmentally friendly technologies such
as solar panels in your projects Please give us some examples Table A2 11 - Innovative technology integration
Company Responses
A Our homes are all self-powered only company in the world to be doing this
B
This factory allows for site installation of solar panels and other energy savings processes on site by the independent builderbuyer of our modular building materials Modular makes the most sense to be used by architects and builders with environmentally friendly tech
C
Modules (flat packed floor wall and roof components) are constructed of ply and highly insulated with non-petroleum-based insulation (recycled glass as a fibre) Solar panels fitted as an add on to completed building
D None yet not been asked
E Solar technology is YES
Q Automation in off-site production generates less or more waste of material There
are some argues about less waste generation in manual activities because of better
sense of material resistance by normal labour (wooden material for instance) Table A2 12 - Automation status on waste generation
Company Responses
A we are not automated yet but believe automation will be much more efficient use of materials
B In our experience as a custom modular manufacturer automation has a significant cost that may not be recoverable for many months if not years- millions of dollars in cost of
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
105 | P a g e
components set up and training versus hourly wage and benefits of trained factory workers
C Waste is much reduced and a proportion of the waste is remanufactured to smaller items or sold on to handymen
D Would be less waste but we do not use much automation
E -
Q How much reduction does off-site modular construction has in generating ldquowasterdquo in
comparison with traditional construction methods Table A2 13 - Reduction of waste
Company Responses
A 70 less waste
B I am unable to provide an answer to this question
C
As we are timber people emissions are low regardless of construction methods Steel and concrete use are kept to a minimum and these are the high emission materials
D We are still working on our carbon footprint
E 15 less carbon emission
Q How much reduction has in ldquoenergy consumptionrdquo off-site in comparison with
conventional on-site construction What about during the operation phase Table A2 14 - Energy consumption status
Company Responses
A Our homes are not positive from an energy perspective
B
Energy consumption of a factory is known and relatively constant on a weekly monthly and annual basis The modular components for a two-box ranch style house require 3 workdays on our factory floor and 4 more days in final finish prior to shipment A competent and experienced modular builder can many times finish the entire project using modules in 8-10 weeks from ground-breaking to issuance of the CO A similar site-built house could require as much as 4 months for the same completion
C Not assessed but doubt there is much difference
D We are still working on our carbon footprint
E 30 energy saving
Q Did you deliver any projects for providing emergency services in Covid-19 period You
can mention the projects in the other section Table A2 15 - Delivery of projects in COVID-19 pandemic period
Company Responses
A No
B No
C No
D No
E Yes
Q Did you construct any projects for world aid organizations and charities You can
mention them in the other section
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
106 | P a g e
Table A2 16 - Aid organization project delivery
Company Responses
A No
B No
C No
D No
E Yes
Q Do you offer post-sale services to your clients Table A2 17 - Post-sale services to client
Company Responses
A Yes
B No
C Yes
D Yes
E Yes
Q How much was your initial costs estimate (Factory set up etc) How long was the
investmentrsquos payback period Table A2 18 - Initial costs
Company Responses
A 20 million Canadian dollar 5-year payback
B What costs Factory set up or cost of modular product sold to builders What about labour engineering transportations etchellip
C The business has been building up over decades so it is not possible to isolate specific costs
D -
E 15 million USD 5 years
Q Which factors can change the initial costs Table A2 19 - Effective factors on initial costs
Company Responses
A Level of automation Product types and production range Less sub-contracts Site location
B Design of modular building- ie roof system high wind heavy snow loads etchellip Product types and production range Site location
C Financing Level of automation Product types and production range Less sub-contracts
D Level of automation Product types and production range Site location
E Level of automation Product types and production range
Q Can component re-use building portability and the life cycle value of materials be
used as a strategy to ldquocompensaterdquo for higher initial construction costs Table A2 20 - Re-use effect on budget
Company Responses
A -
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
107 | P a g e
B
We use many lumber cut-offs PVC drainpipes and conduit and dry wall pieces over many modular orders Unusable drywall shingle and PVC pieces are collected and sent out for recycling Wood is collected and recycled into mulch product or used for heating by others
C Not easily Our methods (flat pack) due not lend themselves to building portability
D -
E 50 years life span of the products
Q Which factors did you consider for choosing modular construction over traditional
method Table A2 21 - positive factors about modular construction to be chosen
Company Responses
A traditional construction is broken
B
Speed ease and cost of overall construction Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
C Transportation costs and boundaries Local salary wages Existence of experts Environmentally friendly
D Transportation costs and boundaries Local salary wages
E Transportation costs and boundaries Local salary wages Environmentally friendly
Q Do use BIM in your projects what are the challenges in using BIM Table A2 22 - Use of BIM in projects
Company Responses
A 100 BIM from conceptual to finished models
B No
C No
D No
E No
Q What effects the production line can have on the design Are there any boundaries
on the architectural design Table A2 23 - Influence of production line on design
Company What effects the production line can have on the design Are there any boundaries on the architectural design
A No you just need to design with our subassemblies in mind
B This factory maximum module dimension capability is 15rsquo9
C Workshop prefabrication gives the architect far more design freedom
D Width of building for transport to make economically viable
E No
Q Is there any lack of knowledge from architects or design engineers in modular industry
about production line processes transportation limitations etc
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
108 | P a g e
Table A2 24 - Lack of knowledge among experts
Company Responses
A Yes
B No
C NA
D Yes
E Yes
Q How state transport regulation and approval can harm the projects in cost and time
Have you experience delays in your schedules because of those Table A2 25 - Transportation regulation effect on projects
Q Does the concept of transportable materials add extra costs on the project Do the
reduction of material waste and multiple discounts can ldquocompensate the lossrdquo Table A2 26 ndash Transportable material choice and its effects
Company
Does the concept of transportable materials add extra costs on the project Do the reduction of material waste and multiple discounts can ldquocompensate the lossrdquo
A Transportation costs are offset by speed of production and reduced financing costs for the project
B Not significantly
C See 26 The reverse applies
D No
E No
Q What are the difficulties in using automation in off-site production processes Table A2 27 - Challenges of using automation
Company Responses
A Codding Integration with advanced software
B Cost
C -
D Integration with advanced software
E Codding Cost Lower salaries of manual processes by labour
Company
How state transport regulation and approval can harm the projects in cost and time Have you experience delays in your schedules because of those
A Yes Some areas are slow to respond
B
Yes Some states in the US are more difficult to ship oversized and ldquosuper loadsrdquo through This adds both time and expense to the projects
C No Our company prefabricates and flat packs so all components are within or close to legal load limits
D No
E Yes
Modular Construction potential advantages and common challenges | Masoud Veiskarami Anexo B
109 | P a g e
Q Which problems exist in modular construction in terms of contracts What are the
solutions Table A2 28 - Contract condition in modular industry
Q What are the challenges in defining responsibilities among participants of a project
due to the changing most of the activities to precast solutions Table A2 29 - Participation status in modular projects
Company
What are the common errors than can harm the synchronization of productivity between off-site production transportation and on-site installation progress For instance less demands on-site caused
A Lack of quality partners on site that see the benefits of modular and therefore increase their pricing
B
The builder owns the responsibility to ensure that site work is done on time and correctly Delays in this can result in postponed transport of product and interest through demurrage charges
C Provided control is tight none
D -
E -
Q Considering all components are prefabricated offsite what is the role of an outside
general contractor Table A2 30 - Role of outside general constructor
Company Responses
A will always need some component of site work to complete the project
B
An outside general contractor is the independent builder The modular factory is a material vendor to the general contractor The general contractor is responsible for all site work and permits as well as storage- installation- and finish of the modular product forming the house or structure they are building
C We do not use outside general contractors All stages from earliest concept design to completed building are in house
Q How often advantageous changes must be done in the production line and what are
the challenges
Company Which problems exist in modular construction in terms of contracts What are the solutions
A Every state has a different building code need a universal code
B
In some cases the end home buyer believes the factory to be the builder and the actual independent builder to be a sales agent for the factory Our company addresses this through accuracy in the relationship described on our website and social media as well as requiring the builders customer to sign a disclosure acknowledgement from that describes the relationship in detail
C Banks do not recognise work done until it is erected on site This creates cash flow pressure where bank finance is involved
D -
E Delivery on time
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Table A2 31 - Changes in production line and its effects
Company Responses
A Slows down production
B This company incorporates changes to product materials or procedures between orders A change in process will not occur that affects only some of the components of an order
C Not sure I can answer that ion the space All means of production have advantages and challenges We have chosen methods and stick to them
Q Do you have sub-contracted players involved in your project for site preparation and
foundation phase etc why Table A2 32 - Site preparation status
Company Do you have sub-contracted players involved in your project for site preparation and foundation phase etc why
A Yes Because we are selling in many geographic areas we need local representation
B No This is the responsibility of our customer- the general contractorindependent builder
C Yes Under direct supervision Their equipment is expensive and not portable It makes sense to use local contractors for footings
D -
E Yes
Q If the onsite foundation is constructed by an outside general contractor are there
additional challenges at the interface in terms of a technology gap the equipment or
tools used the construction experience of workers or in scheduling and phasing of
construction Table A2 33 - Challenges with sub-contractors for site preparation phase
Q What are the wrong perceptions about modular products among market and public Table A2 34 - Wrong perceptions for modular products
Company What are the wrong perceptions about modular products among market and public
A that their only quality is being cheaper
B
In the USA many people the media and even professional engineers do not understand the capabilities of modular construction Many people continue to confuse this form of construction with HUD on frame products
C With our methods (flat pack) that prefabrication reduces the design options The reverse is the case
Company
If the onsite foundation is constructed by an outside general contractor are there additional challenges at the interface in terms of a technology gap the equipment or tools used the constructionhellip
A we need to educate most local subs on our process and reason for doing things a certain way
B Not that directly affects the factory
C No
D -
E -
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Q What strategies are taken among manufacturers to either improve the public
perception of modular construction or to promote its advantages to architects and
potential clients Table A2 35 - Solutions for wrong perceptions
Company
What strategies are taken among manufacturers to either improve the public perception of modular construction or to promote its advantages to architects and potential clients
A Going fast Proving the superior nature of our homes by getting more of them into the world
B
There is some cooperation between builders manufacturers architects and engineers to educate the public The national entity is the Modular Home Builders Association See httpswwwmodularhousingcom
C Nothing specific We advertise our advantages and it is enough
Q Any other challenges and recommended solutions for them that you want to add
please Table A2 36 - Recommendations
Company Responses
A -
B -
C The capital cost of equipment Specialised digital equipment is expensive making it difficult for small and medium companies to enter the market