BIM Curriculum Lecture Notes

70 Pages·2006·18.92 MB·English

BIM Curriculum
Lecture Notes
Graphisoft
Visit the Graphisoft website at http://www.graphisoft.com for local distributor and product availability information.
BIM Curriculum – Lecture Notes
Copyright © 2006 by Graphisoft, all rights reserved. Reproduction, paraphrasing or translation without express prior written permission is
strictly prohibited.
Trademarks
ArchiCAD , Virtual Building™ and Virtual Building Solutions™ are trademarks of Graphisoft.
®
All other trademarks are the property of their respective holders.
C
ONTENTS
Contents__________________________________________________ 3 Complexity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Model Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
BIM Lecture 1: Introduction to BIM___________________________ 7
Big Buildings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Evolution of AEC CAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Hardware Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
AEC CAD Timeline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Software Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Working concept - 2D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Computer Modeling Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Evaluation of the 2D CAD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Working Concept – 3D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 BIM Lecture 3: Computer Visualization_______________________ 21
Evaluation of 3D CAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Technology Timeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
The BIM Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Visualization Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Working Concept of BIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Standard BIM Visualization Workflow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Evaluation of the BIM Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Complex Visualization Workflow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Real Architectural Elements - BIM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Photorendering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Model Based Documentation - BIM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Scene Layout Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Estimation-BIM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Computer Shading Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
External Collaboration-BIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Computer Rendering Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Internal Collaboration-BIM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Advanced Rendering Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Analysis, Coordination-BIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Non-photorealistic Renderings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Industry Trends – Construction Coordination. . . . . . . . . . . . . . . . . . . . . . . .13 Fly-Through Animations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Virtual Construction Workflow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Animation Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Sun Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
BIM Lecture 2: Computer Modeling___________________________14
Virtual Reality (VR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Modeling Decision Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
QuickTime VR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Purpose of the Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Conceptual Modeling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 BIM Lecture 4: Publish Your Work ___________________________ 29
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 External Collaboration with BIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Modeling for Visualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 File Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
BIM Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 IAI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Modeling for Construction Coordination. . . . . . . . . . . . . . . . . . . . . . . . . . . .16 IFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Virtual Construction Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Sharing the BIM Data: IFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Model Complexity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 IFC Implementation Examples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
BIM Curriculum – Lecture Notes 3
Contents
Sharing model data: XML. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Resources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Sharing documents: PDF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 The 5D Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
PDF Implementation Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Benefits: Clash Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Sharing Drawings: DWG-DXF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 Benefits: Cost Variances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Reviewing: DWF. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 Variance Estimating©. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Reviewing Workflow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 Benefits: Design to Build. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Trends: Google Earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 Benefits: Build to Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Trends: U3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 Virtual Construction™ Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
BIM Lecture 5: Collaboration________________________________34 BIM Lecture 7: Calculation__________________________________46
Collaboration in the Office. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 Calculation with BIM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Office Organization: Small Office . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 Element Identification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Office Organization: Large Office . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 Quantity take-offs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Internal Collaboration-BIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Accuracy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
The Teamwork Concept. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Evaluation of Teamwork. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Benefits of Using Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Workspace Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Send & Receive Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Inventories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
More Teamwork Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Cost Estimation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
The Hotlinked Files Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Cost Estimation with BIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Evaluation of the Hotlinked File Method . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Interactive Schedule Workflow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Complex Projects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Calculation Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
BIM Lecture 6: Construction Coordination_____________________39 BIM Lecture 8: Sustainable Design ___________________________50
Problem Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Construction Planning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Sustainable Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Traditional Design Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Environmental Impact of Buildings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
New Design Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Regulations & Market Incentives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
The Virtual Construction Model (5D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Why should architects go green?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
5D Work Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Sustainable Design with BIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Construction Modeling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 Case Study: Kirksey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Recipes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 BIM as Collaborative Foundation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43 Data Sharing via IFC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
4 BIM Curriculum – Lecture Notes
Contents
Applications: ArchiPHYSIK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54 Sources of GDL Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
Applications: Green Building Studio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
BIM Lecture 10: Computer Aided Manufacturing_______________ 64
Applications: ECOTECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Energy Analysis with Archicad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 CAM in the Construction Industry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
BIM-CAM workflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
BIM Lecture 9: Parametric Object Technology__________________57
Prefabrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Object Technologies in CAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Case Study: Log Home Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
Benefits of the Parametric Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
What is GDL? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Structural Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
Highlights of GDL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Placing Doors and Windows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
What can you do with GDL? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Assigning Wall ID’s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
GDL Basics: Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Creating Wall Drawings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
GDL Basics: 3D Shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Quantity Take-offs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
GDL Basics: 2D Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Preparation for Manufacturing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
GDL Basics: Transformations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
GDL Basics: Graphical Editing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 Log Manufacturing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
GDL Basics: Graphical User Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 Packaging and Shipping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
Free GDL Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62 On-site Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
GDL Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62 Case Study: Steel Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
BIM Curriculum – Lecture Notes 5
Contents
6 BIM Curriculum – Lecture Notes
BIM Lecture 1: Introduction to BIM
BIM L 1: I BIM
ECTURE NTRODUCTION TO
Topics A major milestone of AEC software history was the release of 3D
CAD applications capable of handling three-dimensional models in
• History / Overview
addition to the 2D documentation. Some of these programs also had
• From 2D to BIM
basic visualization functions, such as photo rendering engines and
• The BIM concept simple movie tools.
• Future Trends Contemporary BIM applications provide integrated solutions for
There is a lot of talk these days about model-based design, Building architects and designers. Developed specifically for the AEC industry,
Information Modeling: BIM, or Virtual Building to mention just the BIM programs feature real building elements, automatically
some of the names this approach is often given. The topic of this attached building information data and rich visualization capabilities.
lecture is what does this really mean and how does this approach The latest AEC applications focus on the construction industry.
differ. Adding time and cost information to the 3D BIM model (making it
into a so-called “5D” model) allows construction companies to
EVOLUTION OF AEC CAD optimize their processes and minimize the risk of building errors.
CAD (Computer Aided Design) applications have gone through AEC CAD TIMELINE
major changes over the course of time. The evolution of CAD
software was particularly significant in the AEC (Architecture,
Engineering and Construction) industry, in which simple two
dimensional drafting programs have evolved into integrated building
information modeling (BIM) applications during the past 30 years.
The most important milestones of AEC CAD are the following:
• 2D solutions
Electronic drafting board
• 3D solutions The history of CAD goes back to the early sixties. In this pioneering
Modeling for purely visualization purposes era of computer science, researchers and programmers laid the
foundations of the CAD industry. Computer input devices (such as
• BIM solutions
the mouse) and basic computer interface techniques were also
Models with integrated architectural information
invented that time.
• Construction Coordination (5D)
The first commercial CAD applications were released in the seventies
Timing/scheduling and Cost estimation for mainframe computers and workstations. Since these machines
Early commercial CAD applications were no more then electronic were very expensive, computer-aided drafting remained the privilege
drafting boards capable of creating 2D drawings only. of state institutions and large design firms (mainly in the engineering
industry).
BIM Curriculum – Lecture Notes 7
BIM Lecture 1: Introduction to BIM
The breakthrough in CAD usage came in the early eighties, with the WORKING CONCEPT - 2D
appearance of personal computers on the market. The drop in
computer prices opened the way for smaller architectural firms to Before we talk about the BIM concept, let’s take a closer look at the
start experimenting with CAD drafting. earlier CAD methods. 2D applications are nothing more than
Thanks to the rapid development of computer hardware and “electronic drafting boards” capable of providing only
computer programming, within a few years 3D CAD solutions two-dimensional drawings, without the capability for 3D models.
followed the 2D CAD applications. The working concepts of 2D
By the end of the eighties, CAD developers realized that different CAD are the following:
industry segments required different solutions. The 1990’s were • Draft everything in 2D
characterized, then, by specialization of CAD software. The Building
• No 3D model is created
Information Modeling concept was also developed during these
years, although some revolutionary CAD companies released similar • Design changes maintained
products in the early eighties. manually on every drawing
The latest trend in the industry is the integrated solution offered for • Typically, each drawing is saved
construction companies. This approach is also known as 5D CAD in its own file
(3D+time+cost).
EVALUATION OF THE 2D CAD
The most important benefits and drawbacks of 2D CAD are listed
below. 2D CAD has major advantages compared to hand drafting,
but it cannot provide solutions for many problems facing designers.
The most critical drawback of 2D CAD is the lack of automatic
change management among multiple drawings.
Benefits
Compared to hand drafting
The adoption of new CAD concepts by institutions and businesses • Faster modifications
usually followed the industry innovations with a few years delay. The
• Accuracy
accompanying chart shows the tendencies in CAD usage during the
past 30 years. • Smart drafting tools (fills, dimensions)
As you can see, from the mid-80s onwards, more and more of the • Repetitive elements (blocks, xrefs)
industry has adopted some form of CAD, and we are now going to Compared to other CAD methods
discuss the 3 most common CAD methods
• Easy to understand concept (electronic drafting)
• 2D CAD
• Relatively small files due to reduced data
• 3D CAD
• Quick (but less intelligent) solution for all building types
• BIM
Drawbacks
8 BIM Curriculum – Lecture Notes
BIM Lecture 1: Introduction to BIM
• Changes on one drawing don’t influence other drawings EVALUATION OF 3D CAD
• Drawing coordination is essential
Some of the benefits and drawbacks of 3D CAD are given on this
• No additional content compared with hand drawing
slide. In general, 3D applications provide many advantages for
• Collisions and other design problems are difficult to identify
architects and designers compared to 2D CAD and hand drafting.
Visualization and listing are just the two most obvious benefits of 3D
WORKING CONCEPT – 3D modeling. Even so, 3D CAD also has major drawbacks compared to
BIM. Most importantly we can mention the lack of real architectural
The main features of 3D CAD are: intelligent elements and automatically updated documentation.
• The application has both 2D and
Benefits
3D capabilities
• Buildings can be modeled in 3D Compared to 2D CAD
if necessary • Easier checking of planning errors
• 3D and 2D information can be • Managing changes is easier
included in a single file
• Visualization and calculation
• Drawings are (partially) derived
Compared to BIM
from the model
• Users may work purely in 2D if they wish
• No automatic documentation
• Smaller file size
• Application mostly works with
• Easier to model complex geometries
2D and 3D drawing tools instead
of real architectural elements Drawbacks (compared to BIM)
• Additional content can be • Concept doesn’t follow the architectural design process
created, including visualization • Documentation is not fully automatic
and basic quantity take-offs
• No architectural content like in BIM applications
3D CAD programs allow users to create a spatial model of the THE BIM CONCEPT
building together with the necessary 2D documentation. Some
drawings (e.g. sections or elevations) can be partially derived from the Definition: BIM= Building Information Modeling
3D model but in most cases the documentation is kept in a separate
Also known as “Virtual Building” or “Building Simulation”
file (or set of files) from the model. Most 3D applications offer
built-in visualization tools and basic quantity calculation features (e.g.
floor areas, roof areas).
BIM Curriculum – Lecture Notes 9
BIM Lecture 1: Introduction to BIM
• Additional materials (rendering, animation, quantity take-offs,
schedules)
• We must emphasize that unlike in 3D CAD, the BIM model
consists of real architectural elements (walls, slabs, roofs, etc.) and
the documentation workflow is automatic.
EVALUATION OF THE BIM CONCEPT
Since the BIM concept was initially developed to serve the AEC
market, it offers many particular advantages for architects and
designers compared to traditional CAD methods. The only possible
drawback of BIM is the relatively higher training requirements of
novice users and cross graders from 2D applications.
The basic concept of BIM modeling is that architects are able to use
Benefits
the 3D building model to extract all the required project drawings and
building views – including sections and elevations, presentation Compared to 2D and 3D CAD
drawings, renderings and detailed construction drawings, as well as • Elements have architectural meaning
quantity calculations and price estimations. Consequently, changes to
• Changes on one drawing have influence on all others
the model are instantly updated on all drawings. The image below is
• Rich visualization content (animation, sun studies, renderings etc.)
an illustration of this concept.
• Automatic quantity take-offs, schedules
Working with a 3-Dimensional building model gives the architects
flexibility and benefits that are not available in a traditional 2D • Connection to structural, energy calculation, collision detection
building project. The commonly used phrases ‘Virtual Building’, etc. software
‘Building Simulation’ and ‘Building Information Modeling’ are largely Drawbacks
interchangeable.
• Higher training requirements
WORKING CONCEPT OF BIM • Might be difficult to learn the BIM approach for people who were
previously 2D users
The most significant highlights of the BIM method are: • Might be more difficult to handle complex geometry (e.g. freeform
structures) then in 3D and 2D CAD
• Single file concept: The complete building model and all of its
representations are included in the virtual building file
REAL ARCHITECTURAL ELEMENTS - BIM
• Real architectural elements used for modeling
• Changes to the model affect all related drawings (and vice versa)
The BIM model is made of real architectural elements that are
• Automatic generation and updating of documentation represented correctly (according to local architectural standards) in all
• Architectural content (libraries) views. Furthermore, non-graphical building information data can be
• Building information data attached to the elements
10 BIM Curriculum – Lecture Notes