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Building Information Modeling (BIM)
and its application in AEC sector, Part 1
By:
Mehdi Heidari, Ph.D., P.Eng.
❑ Introduction
❑What is BIM
❑Why BIM
❑How BIM works
❑Collaboration in a BIM-based project
❑BIM Inaccuracies and Obstacles
2
Introduction
Transition from manual drawing to CAD-based approaches improved the
efficiency of the process
Transition from paper-based “silo” workflow to a “BIM-centric” design
approach fundamentally changes the process and the AEC workflow
Photo from: cadsourcing.com
❑ For many decades, the AEC community has relied on a paper-based workflow with
designers working in “silos”
➢ Focused on a single project discipline or function and sequentially passing the outputs of their
design decisions on to the next discipline.
➢ This isolated, sequential process created many barriers to effective collaboration
➢ Often led to misunderstandings and mistakes requiring costly rework in the field.
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❑ In recent years, the AEC community has embraced a new methodology using BIM
software tools and building information models as the basis for a collaborative design
process to meet the challenges of today’s increasingly complex project requirements.
➢ Enables multidisciplinary design teams to create,
share, and coordinate project information
➢ BIM is proving to be a breakthrough technology that
affects project workflows, multidisciplinary team roles,
delivery methods, and project deliverables.
➢ Design teams can deliver projects on time,
at a higher quality, and with greater efficiency.
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Each team member must develop the information needed and design the features required for
their own portion of the design work,
and this information must be shared with other members of the design team who are
impacted by and depend upon these design decisions
What is BIM?
7
❑ A digital representation of the physical and functional characteristics of a facility.
▪ BIM is not 3D; 3D is a helpful part of BIM.
▪ BIM is not Revit; Revit is a great tool for BIM.
▪ “Data-Rich” Virtual Model of a Project – the “i” in BIM.
▪ Coordinated and commutable; BIM is a world of collaboration.
▪ Introduced to help communicate more effectively to avoid
small and large unforeseen errors.
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▪BIM is not 3D; 3D is a helpful part of BIM.
▪BIM is not Revit; Revit is a great tool for BIM.
▪
▪“Data-Rich” Virtual Model of a Project – the “i” in BIM.
▪Coordinated and commutable; BIM is a world of collaboration.
▪Introduced to help communicate more effectively to avoid
small and large unforeseen errors.
➢ A Process (not software) – A New Way of Doing Things
➢ Not CAD (2D line-based drafting / no inherent intelligence)
➢ Production of Reliable and Coordinated Documentation
➢ Recording all Vital Design Information in a Single Database
➢ Used by all Stakeholders throughout the Projects Lifecycle
➢ Part of IPD (Integrated Project Delivery)
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➢ A shared knowledge resource for information about a facility, forming a reliable basis for
decisions during its life cycle, from earliest conception to demolition”
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Why BIM?
❖ Achieve improvements in programme, productivity & quality
Information “Chaos” “Shared” Project Model
Source: Lahif, Garland and partners (2012)
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❖ A fundamental advantage of using a BIM-based methodology for sharing
project information and collaborating is that:
➢ It enables design team members to participate and provide their inputs much
earlier in the design process, rather than waiting in line for their turn after earlier
design decision are locked.
▪ Early participation and input enables all design team members to assess the impacts of
their design decisions and processes downstream.
▪ Enables designers to respect the requirements of the other design disciplines and avoid
costly and time-consuming conflicts and design rework.
12
❖ Address design challenges more properly.
Source: Lahif, Garland and partners (2012)13
➢ A More Sustainable Model of Building Procurement
▪ Address Economic & Environmental Issues in Construction
▪ Waste in Construction
▪ Buildings Cost Too Much to Build
• Buildings Cost Too Much to Operate
• Buildings responsible for 50% of CO2 Emissions
▪ 30% of the cost of construction is wasted in the field due to:
• coordination errors
• wasted material
• labour inefficiencies
• other problems in the current construction approach
(Report, “The Economist”, January 13, 2000) 14
➢ Stanford University Center for Integrated Facilities Engineering (CIFE) figures
based on 32 major projects using BIM indicates benefits such as:
▪ Up to 40% elimination of unbudgeted change.
▪ Cost estimation accuracy within 3%.
▪ Up to 80% reduction in time taken
to generate a cost estimate.
▪ A savings of up to 10% of the
contract value through clash detections.
▪ Up to 7% reduction in project time.
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How BIM works?
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BIM Project Execution Planning Procedure
BIM software tools
Developing a Model Coordination Plan
Before members of the design team dive into creating models for their individual pieces of the project, it is essential that key members of the team meet to create standards and document the procedures that will be used to share models. This step specifies:
▪ The overall strategy for dividing the design work into packages that will be completed by different members of the multidisciplinary design team.
▪ Who is responsible for the development and analysis of each work package at each stage of the design process.
▪ The acceptable level of detail for each work package at each stage.
▪ The information exchange mechanisms (network server, FTP site, or other file transfer means) and standards (file formats).
▪ Who has management or editing privileges for each work package.
Understanding BIM within REVIT
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Computer developed.
No longer need to leave workplace/office
All of the collaboration happens online/within a CLOUD service
Comment about what “will or will not work” based on various analysis completed
because we have real world modeling completed.
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Collaboration in a BIM-based project
While the local benefits of adopting a BIM-based design
approach to improve the workflow and outputs of each
design discipline—architectural, structural, and MEP—
are typically far greater than the costs of deploying BIM
and sufficient to justify making the change.
➢ The larger impacts of enabling seamless
multidisciplinary collaboration by the
entire design team are far greater.
Collaboration Methods
1. Worksharing through worksets allows simultaneous access to a shared model through use
of a central model. A Workset is a collection of elements in a workshared project.
2. Linked models, project elements are separated into individually managed models that
can be linked together.
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➢ Use worksharing when you are working with a single model (one RVT file) that will
have multiple team members working on it.
➢ Use linked models when your project contains distinct buildings, such as a campus, or
when you are working with team members from other disciplines, such as:
▪ Architects
▪ Structural engineers
▪ Mechanical engineers22
1. Working through Workset
➢ Worksets can be based on functional areas, such as the following:
For architecture and structural engineering: interior, exterior, and site
For systems: HVAC, electrical, or plumbing
➢ The important distinction when working with ownership of objects in a workset is
between making a workset editable and borrowing from a workset.
➢ Only one user can exclusively edit each workset at a given time.
➢ All team members can view worksets owned by other team members, but they
cannot always make changes to them. This restriction prevents potential conflicts
within the project.
➢ It is possible to borrow an element from a workset that you do not own.
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2. Linking multi-disciplinary models
❑ Preparing to Share Models
A preliminary Base Design Model generated by the lead architect
❑ Utilize the Base Design Model
Share the BIM model with other members of a multidisciplinary design team
❑ Review and Coordinate Designs
Cross-linking of models produced by all disciplines.
Creating the Architectural Building Model
➢ Create a dimensional framework of levels, grids, and reference planes that all
members of the team can use to place elements and keep their work coordinated.
Grids and reference planes for a typical level
➢ Designers typically place elements in their models to act as placeholders for items
that will be designed and specified by other members of the team.
➢ This approach enables architects to consider the locations in their design decisions
and indicate their design intent.
Placing structural columns
in the architectural model
Placing Plumbing Fixtures
in the architectural Model
Placing Lighting Fixtures
in the architectural Model
Modeling Structural Elements
➢ Link the preliminary architectural model to your Revit Structure host project
➢ Use the Copy/Monitor tool to copy shared elements:
▪ Dimensional framework—levels and grids
▪ Placeholder elements—walls, floors,
and columns placed in the architectural model
➢ Model the structural elements using the Structural tools in Revit Structure.
❖ Basis for detailed structural analysis and design to confirm the sizes of all members.
Moving columns by adjusting
the grid locations3D Structural Frame view
Modeling Electrical Systems
➢ Link the architectural model to a Revit MEP host model
➢ Use the Copy/Monitor tool to copy the
placeholder lighting fixtures to use as the
starting point for the electrical design tasks.
➢ Add electrical elements to the host project
▪ Electrical equipment
▪ Devices
▪ Lighting fixtures
❖ The electrical model can be used for analysis and shared with the other members of the design team and disciplines affected by the electrical design decisions.
Lighting fixtures in the linked architectural
model are copied to MEP file
Modeling Plumbing Systems
➢ Link the architectural model to a Revit MEP host model
➢ Use the Copy/Monitor tool to copy the
placeholder elements to use as the starting
point for the plumbing design tasks.
➢ Add plumbing elements to the host project
▪ Add pipes to model vertical risers.
▪ Add horizontal branch pipes
▪ Connect plumbing fixtures to the branch pipes.
▪ Fire sprinklers and their piping
❖ The plumbing model can be used for analysis and shared with the other members of the design team and disciplines affected by the plumbing design decisions.
Copying plumbing fixtures in the linked architectural
to the Revit MEP host project
Modeling Mechanical Systems
➢ Link the architectural model to a Revit MEP host model
➢ Use the Copy/Monitor tool to copy levels and grids to use as the starting point for the plumbing design tasks. Do not need to copy any fixtures from the linked model.
➢ Add HVAC systems to the host project
Place air handling unit components.
Place supply and return diffusers
Connect the diffusers to the air handling units with ducts
❖ The mechanical model can be used for mechanical system analysis and design, as well asshared with the other members of the design team and disciplines affected by the mechanical design decisions.
Coordination and Interference Checking
a) Coordinating and Reviewing Model Changes
➢ Link the Autodesk® Revit® Structure and Autodesk® Revit® MEP models created
by other disciplines in the design team model
➢ The software automatically looks for changes to any shared elements. The
coordination review reports:
▪ Type of change
▪ The shared element
▪ Recommended actions
Reviewing changes to shared elements in the coordination
b) Checking for Interference Between Model Elements
➢ Use this tool in two ways, to:
1. Compare the locations of elements placed in a single model.
2. Compare elements in a host project to elements in a linked model.
For example; Link the HVAC model to the plumbing model
Clash between a duct and sprinkler pipe
BIM-Inaccuracies
Types of inaccuracies could arise from BIM integration:
▪ Loss of information?
▪ Lack of information?
▪ Problems with integration or transmitting?
▪ Collaborators not updating model.
▪ Collaborators not using updated software
(i.e. Revit Versions or correct software). 35
BIM-Obstacles
➢ Contractual and legal requirements
➢ – Conditions of Contract
➢ – Legal precedent
➢ Allocation of risk
➢ Sharing of reward
➢ Standardised information exchange
➢ Implementation costs
➢ – Education and training
➢ – Software and hardware
➢ – Development of component libraries
➢ Changing established business processes 36
Building Information Modeling (BIM)
and its application in AEC sector, Part 2
By:
Mehdi Heidari, Ph.D., P.Eng.
❑ Cost Estimation
❑ Building Energy Modeling
❑ Parametric Modeling
❑ Structural modeling
❑ Auto-Generating structural design
2
Cost Estimation: 5D BIM
➢ Conventional estimating techniques that rely on two-dimensional drawing measurements have
substantial potential for ambiguity, inefficiency, and error.
➢ A 5D estimate is a BIM linked to construction cost estimation through material quantities that are
automatically generated from the data within the model.
➢ When the design is changed, cost adjustments are calculated in real time. All (with a few exceptions)
Views in Revit are live views of the model.
➢ 5D Estimation improves budgeting, provides cost-loaded schedules, and displays multiple
interactive forecasts to make agile comparisons. This enables general contractors to help the
owner improve design with value-engineering decisions.
3
Simple example
Derive costs of the walls based on their areas in the project and assign unit costs for
delivery?
4
Wall schedule
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Create a Formula that will derive the total cost of each wall.
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Organization to the schedule; sorting/grouping tab
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Building Energy Modeling (BEM)
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• Solar Shading
• Lighting
• Heating Cooling
Kestrel court Project
Application of BIM for advanced energy modeling of a Zero Net Energy home
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Net Zero Energy (NZE) home
➢ Deep Energy Retrofit comprises all energy conservation measures to improve the energy performance of a
building as a whole.
It consists of an integral approach to
reconfigure the interior, for the
replacement of building elements,
rearrangement of fenestrations
and alternate HVAC systems.
➢ Another cost-effective method to improve the energy efficiency is to upgrade the existing buildings to the
Net Zero Retrofit level. NZE homes can produce energy equivalent to or more than what is expended.
10
Model preparation: Input BIM Data for Analysis
➢ Design Conditions
Location
Latitude
Elevation
Outdoor temperature and relative humidity
➢ Orientation
➢ Internal conditions (Indoor temperature and relative humidity)
➢ Building Enclosure
Insulation levels of walls, ceilings, and floors
Window specification
Thermal conductivity
Solar Heat Gain Coefficient (SHGC)
Infiltration and ventilation levels
Interior and exterior shading
➢ Internal loads
Number of occupants
Electronics, lighting and appliances. 11
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Location, Orientation and weather data
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Level of Detail (LOD)
I. Conceptual Type
II. Schematic Type
III. Detailed Elements
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Building Envelope
R-value: A measure of the thermal resistance
(or resistance to heat loss) through a material
layer of a given thickness.
R-value = Thickness / Conductivity.
U-value: Overall Heat Transfer Coefficient
15
Rooms, Space and Zones
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Space parameters
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Zone parameters
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Solar/shadow study
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Lighting Analysis
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Heating/Cooling Load Analysis
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Parametric Modeling
Dynamo is a visual programming tool that works with Revit.
➢ Access to the Revit API
➢ Why Using Dynamo?
1. Automate repetitive tasks
2. Access your building data
3. Explore multiple design options
4. Test Performance
5. Think Computationally
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Simple examples
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Advanced applications
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Structural modeling
CSIXREVIT: data exchange between Autodesk Revit and CSI products
Exporting from Revit® to create a new CSI Software model.
Exporting from Revit® to update an existing CSI Software model.
Importing from CSI Software to create a new Revit® Model.
Importing from CSI Software to update an existing Revit® Model.25
ROBOT
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bidirectional data exchange
between Autodesk® Robot™
Structural Analysis
Professional (Robot)
and Autodesk® Revit® (Revit)
Auto-Generating structural design
➢ Automatic load combination
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➢ Automatic loading
▪ Dead Load
▪ Live Load
▪ Wind Load
▪ Seismic Load
➢ Automatic Analysis and design
➢ Automatic drafting and documentation
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