Consruction Economics Morphology

BE 2401- Construction Economics II Course Work Building Morphology Factors

Acknowledgement

We would like to express our sincere gratitude Mr. S. A. Pussella, Arch. Madhawa Premaratne, Structural

Engineer, Mr. Mahesh and Site Engineer, Mr. Prasanna for their fullest cooperation.

We would also like to acknowledge our Construction Economics Lecturer, Mr. Prasath Sanjeewa, Project

work Lecturers, Mr. C. Jayasena and Ms.Sajani Jayasuriya , for their advice and guidance to complete this

project successfully.

Department of Building Economics i


Table of Contents

Acknowledgement..........................................................................................................................................i

Table of Contents...........................................................................................................................................ii

Table of Figures............................................................................................................................................iv

1.0 Introduction..............................................................................................................................................1

2.0 Building Morphology Factors..................................................................................................................2

3.0 Impact of Design Economics for Cost of Construction...........................................................................3

3.1 Building plan/shape.............................................................................................................................3

3.2 Storey height........................................................................................................................................3

3.3 Height of building................................................................................................................................3

3.4 Grouping..............................................................................................................................................3

3.5 Size of building....................................................................................................................................4

3.6 Build ability/Constructability..............................................................................................................4

4.0 Project Information of the Selected Building..........................................................................................5

5.0 Design Factors Considered in the Selected Project.................................................................................6

5.1 Shape and Size.....................................................................................................................................6

5.2 Size of Building...................................................................................................................................6

5.3 Grouping..............................................................................................................................................7

5.4 Height of building................................................................................................................................7

5.5 Storey Height.......................................................................................................................................8

5.6 Circulation Space.................................................................................................................................8

6.0 Analyzing the Design Factors with Various Design Proposals...............................................................9

7.0 Recommendations to Improve the Design.............................................................................................11

8.0 Impact of Design Economics for Cost Planning....................................................................................13

9.0 Conclusion.............................................................................................................................................14

10.0 References............................................................................................................................................15

11.0 Contribution of Group Members.........................................................................................................16

Department of Building Economics ii


Table of Figures

Figure 2.1 Classification of Morphology Factors..........................................................................................2

Figure 3.4 Goruping Methods........................................................................................................................4

Figure 5.1 Sketch of Sasip Building Complex..............................................................................................6

Figure 5.3 Grouping of Building 1 and Building 2........................................................................................7

Figure 6.2 Proposal B....................................................................................................................................9

Figure 6.1 Proposal A....................................................................................................................................9

Figure 6.3 Proposal C....................................................................................................................................9

Figure 7.1 Selected Building.......................................................................................................................11

Figure 7.2 Recommendation 1.....................................................................................................................11

Figure 7.3 Recommendation 2.....................................................................................................................12

Department of Building Economics iii


1.0 Introduction

Buildings come in a wide amount of shapes and functions, and have been adapted throughout history for a

wide number of factors, from building materials available, to weather conditions, to land prices, ground

conditions, specific uses and aesthetic reasons. Buildings serve several needs of society – primarily as

shelter from weather and as general living space, to provide privacy, to store belongings and to

comfortably live and work.

Construction Economics is a branch of general economics which consists of the application of the

techniques and expertise of economics to the particular area of the construction industry. This is also

concerned with man’s needs for shelter and the suitable and appropriate conditions in which to live. It

seeks to ensure the efficient use of available resources to the industry, and to increase the growth of

construction work in the most efficient manner. Construction Economics includes study of several areas

like client requirements, possible effects on surrounding areas if the development is carried out,

relationship of space of shape, assessment of initial cost, reasons and methods of controlling costs and

estimating the life of buildings and materials.

In the last few decades, the construction professionals considered that size and quality of a construction

project are the main items which affect the cost of construction. But nowadays it is quite clear that cost of

construction of a particular design solution is not limited to those two factors but is influenced by many

other factors, some of which are interrelated. Building morphology is a new concept which addresses the

design issues of a construction project in relation with cost of construction.

In the first and second chapters of this report, the morphology factors and their impact on cost of

construction is discussed. In this report, a building complex which is still under construction is selected to

do a research on morphology factors. The selected building is Sasip Building which is owned by Mr. S.

A. Pussella. The details of the building are provided in chapter three. The rest of the chapters discuss the

design factors of the selected building and its various design proposals, recommendations to improve the

design and impact of design economics in cost planning.

Department of Building Economics 1


2.0 Building Morphology Factors

Building morphology, also known as design economics aims to provide value to the client’s money who

invested in the construction project. These are the factors which have direct influence of cost of a project

and these are needed to be considered during the economic evaluation of the building or engineering

structure. Design economics factors influence the quantity of the components in terms of area, number,

size and also their quantity in terms of cost.

Unfortunately, insufficient research has been undertaken to date to give clear indications of degree to

which changes in these factors will have on the cost of the building. However, the great depth of

knowledge gained by practitioners provides some general “rules-of-thumb”. In some cases, the variation

of cost can be specified. For an example, if the shape of a single storey building is changed, so that the

area of the external brick cavity wall is increased, it is quite evident that the wall cost will be increased in

direct proportion to the increased area, when all other things being equal.

Though this kind of simple wisdom can be applied to small buildings, it may not be adequate for dealing

with more complex multi-storey structures. If the shape or the height of the building is changed, it may

not be just the extra quantity and quality that have to be paid, but also indirect costs such as different

lifting equipment, improved fixings etc. Hence, morphology factors which are cost parameters of a

project have to be thoroughly considered in determining and reducing cost of a project.

The morphology factors can be classified in to various sections as shown below.

Figure 2.1 Classification of Morphology Factors


Building plan/shape Storey HeightBuilding height Wall:Floor ratioSize of the buildingGrouping Circulation space

Design Factors

Soil(ground) conditionLocation of siteSize of the site

Site Factors

Inflation External environmental factorsClient requirementsBuilding regulations

Other Factors


3.0 Impact of Design Economics for Cost of Construction

3.1 Building plan/shape

The shape of the building has an important effect on its cost. Though the circle is the most efficient

enclosure of space, the cost of building circular work makes it more costly. So the most economic

building shape is square and more a building shape retreats from a square shape the cost of external

envelope increases in relation to the remaining building cost. As a building becomes longer and narrower

or irregular, the wall area increase due to increase of perimeter, which results a higher cost of

construction. In an irregular shaped building, the cost increases due to the greater cost for scaffolding

areas, complexity in setting out of the project and difficulty in cleaning and maintaining the building.

3.2 Storey height

The variations in storey height can affect the cost of building without changing its gross floor area. This is

mainly because of the affect on the elements having vertical component, like staircases and lifts, service

runs and waste pipes, volume of the building in respect of A/C installation, ceiling void, and foundation

as the lower part of the building should be designed to carry the weight of upper floor without any

deformation. So it is quite clear that when the storey height increases, both the cost of construction and

cost of maintenance increases.

3.3 Height of building

The tall buildings are invariably more expensive to build than two-or-three storey buildings offering the

same accommodation, and also taller buildings have greater comparative cost. This is mainly because of

the greater circulation and servicing requirements for larger buildings. As buildings are built taller,

vertical ducts for building services tend to increase in size. Also service-cores, cranes, more plants for

construction process are more likely to be required increasing construction cost of the project.

3.4 Grouping

Grouping of buildings is a process which groups the buildings together either in design stage or

construction stage without affecting the purpose or function of the building. This method can be done by

either connecting building vertically by using common walls and foundation (Figure 3.4) or by

connecting buildings horizontally by using slabs. This will reduce the cost of a wall and a foundation or

the cost of roofs. After grouping the buildings, the resulting building or complex can either be a single

attached building or a single multi storey building. Also the required amount of land or space, time for

construction are less for grouped building, which further reduces cost.



Figure 3.4 Goruping Methods

3.5 Size of building

Through researches, it is found that the increase in size of buildings often produces reduction in unit

costs. As certain fixed costs like site accommodation, plants, temporary services, site offices may not vary

appreciably with the size of the project over head costs would not increase. Also benefits of the

economies of scale in ordering materials and better prices from materials and components can be obtained

and this would cause reduction in unit cost of materials.

3.6 Build ability/Constructability

Build ability is the extent to which the design of a building facilitates ease of construction, subject to the

overall requirements for the completed building. This attempt to integrate design and construction into a

better building that is easier to construct. Good build ability contributes to the project objectives

positively by speeding construction time, lowering capital and lifecycle cost and improve building

performance and maintenance characteristics.



4.0 Project Information of the Selected Building

The selected building complex, Sasip, owned by Mr. S. A. Pussella, is situated at 282/7, High Level

Road, Nugegoda. The main purpose or the function of this building is to provide lecture halls to private

instructors to conduct classes for a large number of students. In addition to this building is designed to

provide facilities for the press which prints the necessary tutorial notes and other documents to be

provided for the students, the Physics Laboratories which are designed to carry out various practices

relating areas in Physics and other basic requirements like cafeterias, toilets etc.

This building complex consists of two buildings (Building 1 and Building 2) which are adjoining each

other. Both buildings have been designed by Arch. Madhawa Premaratne and structural engineer, Mr.

Mahesh and the contractor is Pasalca Builders Ltd.

Building 1

Shape - Square shaped

Orientation - Front elevation facing East

Number of storeys - 4

Roof structure - Steel Monty Roof

Storey Height - 16ft

Total Height - 80ft

Service Integration - Water, Electricity, A/C, Fire fighting System, Telecommunication, Data

Communication, Horizontal and Vertical movement systems, Sewer and Drainage

Building 2

Shape - Irregular shaped

Number of storeys - 4

Roof structure - Flat roof

Storey Height - 16ft

Total Height - 100ft

Service Integration - Water, Electricity, A/C, Fire fighting System, Telecommunication, Data

Communication, Horizontal and Vertical movement systems, Sewer and Drainage

The Building 1 is smaller in size than the Building 2, which mainly consists of small lecture hall with

about 350 student capacity with air conditioning facility. The ground floor of this building consists of a

teachers’ waiting room, a press, and two laboratories.

In Building 2, 1st floor mainly consists of 2 lecture halls, each with the capacity of about 500 students,

canteen, and toilets while 2nd floor consists of one single main hall and 2 classrooms with air conditioning

facility and other necessary facilities. The 3rd and 4th floors consists two main halls with the capacity of

3500 students for the mass classes.



5.0 Design Factors Considered in the Selected Project

5.1 Shape and Size

The shape of the Building 1 is square shape while Building 2 consists of a rectangular and a trapezoid and

as shown in Figure 5.1.

Figure 5.1 Sketch of Sasip Building Complex

This shape of the building complex is one of the main design factors that the designers have to consider.

This building complex as a whole has a unique shape which is a result of combination of square, rectangle

and trapezoid. At first glance, one would think that the owner has given the priory for the aesthetic

appearance of the building and has wasted his money. But when considering the shape of the land, which

is irregular, it is quite clear that this shape has been selected to maximise the usage of land and to provide

adequate space for the building which requires a large circulation area and to provide a car park of 5

vehicles.

5.2 Size of Building

As this building complex mainly consists of lecture halls for students, it requires large circulation areas.

Approximately about 45000ft2 is required to provide lecture halls, laboratories, press, circulation spaces

and other components. As the land area is much less than this value, the designers have decided that multi

storey building with 4 levels would be sufficient to offer the above facilities plus area for landscaping and



car park. So the Building 1 size was selected as 60’x 60’ with 4 storeys and Building 2 as shown in Figure

5.1. The available land is utilized and the most economical size is selected without going for a building

complex with unnecessary floor levels. This prevents the client bearing unnecessary cost of construction.

5.3 Grouping

Though the client needed only one building, the design team came up with a solution of two buildings to

utilize land area. As this increases the construction cost and does not fulfil client’s requirements, the

design team decided to apply the grouping of buildings and construct one single building for lesser cost.

Since the normal grouping methods cannot be applied to this building complex, designers found a new

way of grouping method which fulfils both single building requirement and aesthetic appearance of

building requirement as shown below.

Figure 5.3 Grouping of Building 1 and Building 2

5.4 Height of building

The total height of the Building 1 is about 80ft and total height of Building 2 is about 100 ft. These two

buildings are designed in two different heights to add a new technology to the new building. When we

consider this building complex and the number of occupants it is quite clear that the amount of water

needed for daily chores of the building is high. So in addition to the 3 overhead tanks of 2000l capacity,

the design team has decided to increase the total height of the building 2 and provide a steel Monty roof

for the new building so that the rainwater flowing down could be collected to the roof slab of the existing

building. They have decided to install a system to purify this rain water and send them to the bathrooms

of the two buildings as the water for flushing purpose.



When the multi storey building constructions are considered, the total heights of these 2 buildings are not

nonstandard. As the designers were able to utilize the land area which values largely as it is situated in a

well developed city, the building height has been minimised. Fulfilling the client requirements and

reducing building height at the same time, cost saving for the client happens.

5.5 Storey Height

Since the total building is not air conditioned, and proper and adequate ventilation should be provided for

the lecture halls and other areas. So to fulfil this need, the design team has decided to have 16 ft of storey

height in Building 1 and Building 2. The ceiling void of 2ft is provided in each floor for service ducts,

various pipes, cables and wires.

5.6 Circulation Space

Since these buildings provide lecture halls for a huge number of students, enough circulation space to

circulate and get ventilation and natural light should be provided. Therefore the designers have paid a

special consideration and have reduced circulation area as much as possible without causing any

difficulty or disturbance to the occupants of the building to reduce cost of construction. Therefore, they

have used the maximum circulation space that can be constructed the minimum cost while having the

basic requirements of comfort ability and safety. There are 4 staircases, 1 lift, corridors, lift wells and

stairwells provided adequately.



6.0 Analyzing the Design Factors with Various Design Proposals

The above two proposals had been failures due to the inefficient use of land, did not suits with the shape

of the land, more storeys would have to be provided to fulfil client requirement and the landscaping cost

would increase.

The above proposal had come up as a solution for the inefficient use of land. Though this proposal

overcomes that problem, this is in contrast to client’s requirement of one building and this proposal would

increase cost of construction and does not suitable for the function of the building.

As a result, the design team decided to design to group two buildings in order to design the most suitable

building for this site.


Figure 6.1 Proposal A Figure 6.2 Proposal B

Figure 6.3 Proposal C


Though the Proposal E and Proposal F have lesser cost of construction due to the methods of grouping,

those proposals do not provide adequate space for the car park. Also their aesthetic appearance is not

much as Proposal D. As Proposal D provides adequate space for car park and cost of construction is

reduced, it is selected as the most appropriate design proposal.


Figure 6.4 Proposal D Figure 6.5 Proposal E

Figure 6.6 Proposal F


7.0 Recommendations to Improve the Design

Figure 7.1 Selected Building

Gross floor Area = 7700ft2

Wall area = 16’ (31’+30.23’+100’+100’+65’) x4 = 326.23’x16’x4 = 20878.72 ft2

Wall: Floor = 20878.72: 7700 = 2.71

After considering the above factors in the previous chapter, following two design solutions can be

recommended for the above project to improve the design.

In this recommendation,

Gross Floor Area = 7700+0.5x25x17

= 7912.5ft 2

Wall area =16’

(31’+17’+25’+100’+100’+65’) x 4

= 338’ x 16x4

= 21632 ft 2

Wall: Floor = 21632: 7912.5

= 2.71 ft 2

Figure 7.2 Recommendation 1



In this recommendation,

Gross Floor Area = 65 (100+50) – 0.5x33x50

= 8925ft 2

Wall area =16’ (31’+150’+100’+65’) x 4

= 346’ x 16x4

= 22144 ft 2

Wall: Floor = 22144: 8925

= 2.48 ft 2

Figure 7.3 Recommendation 2

When the above first recommendation is considered, it is quite clear that another 212.5ft 2 of gross floor

area can be added to the building complex with a slight difference in cost of construction as wall: floor is

directly proportionate to cost of construction. But in the second recommendation, the wall: floor ratio

deviates in a considerable amount, causing a reduction in cost. Though the aesthetic appearance is less,

second design is more suitable as it adds 1225ft2 to the gross floor area without increasing cost of

construction.



8.0 Impact of Design Economics for Cost Planning

Cost planning, as part of a cost management framework is a total system that requires commitment from

inception to the completion of the project. This is the method of controlling the cost of s project within a

pre-determined sum up to the tender stage. The purpose of cost planning is to:

Ensure that clients are provided with value of money

To keep expenditure within amount or limit allowed by the client

Integrate costs with time and quality

Design Economics is the process of designing a construction project using morphology factors in order to

have the most economical design which compensates with the budget limit. The two vital aspects to

consider when applying design economics in cost planning are the main factors of morphology affecting

the life of building and how cost planning contributes to the designing of a project.

When the above two aspects are understood, it is easy to find out the degree of impact of design

economics in cost planning. Cost planning begins formally with the preparation of client’s initial brief.

Then the first realistic estimate (cost limit) is established. In the Outline proposal stage of RIBA plan of

work, several proposals for the project will be designed and the Quantity Surveyor (QS) has to prepare

preliminary estimates for all the design proposals.

At this point, the QS have to find out the most appropriate proposal in relation to cost. this is done by

applying design economics and its factors in cost planning to each and every proposal and identify the

strong point and weak points of the proposals considering shape, size, height, grouping, circulation space,

floor height, wall: floor ratio, etc. Then he gets the ability to propose better options which will help to

achieve an effective cost.

At scheme design stage of RIBA plan of work, after considering the client requirement, preliminary

estimates and other factors, one proposal is selected for the project. Then the duty of the QS is to develop

full cost plan for that project. Often the final cost of cost plans is greater than the client’s budget. So it is

needed to find positive approaches in these circumstances, to identify the places where cost reduction can

be made.

After considering the above facts, it is clear that design economics play a major role throughout the

process of cost planning due to the strong relationship between design economics and cost planning.



9.0 Conclusion



10.0 References

Brandon, P. S. and Ferry, D. J., 1984. Cost Planning Of Buildings. 5th ed. London : Granada Publishing

Ltd.

Jagger, D. and Smith, J., 2007. Building Cost Planning for the Design Team. 2nd ed. USA: Elsevier Ltd.

Li, Z. L. and Qi, H. B. An Approach to Building Grouping Based on Hierarchical Constraints [online].

The Hong Kong Polytechnic University, Available from:

http://www.isprs.org/proceedings/XXXVII/congress/2_pdf/3_WG-II-3/13.pdf [Accessed date: 16/08/10].

Seeley, I.H., 1983. Building Economics – appraisal and control of building design cost and efficiency. 3rd

ed. London: The Macmillan Press Ltd.


http://www.isprs.org/proceedings/XXXVII/congress/2_pdf/3_WG-II-3/13.pdf


11.0 Contribution of Group Members

Abdullah M.H. Analyzing the Design Factors with Various

Design Proposals

De Silva K.R.S. Introduction

Design Factors Considered In the Selected

Building

Kamalanathan N. Project Information of the Selected Building

Kumara P.H.P.C. Impact of Design Economics for Cost of

Construction

Perera K.T.P.K. Conclusion

Peries T.A.S. Project Information of the Selected Building

Ranasinghe R.A.H.C. Recommendations to Improve the Design

Ranjan K.P.H. Impact of Design Economics for Cost Planning

Wijewardana W.M.C. Building Morphology Factors


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Consruction Economics Morphology