THE HISTORY, FUTURE AND IMPACT OF BUILDING INFORMATION MODELING
As architecture depends more and more on so ware to enable the representa on of designs, the design of so ware should be explored to understand the rela onships between the design pla orm and the finished architecture. A paradigm shi in architecture is taking place. Building Informa on Modeling (BIM) is being rapidly adopted by firms worldwide for representa on, coordina on and design. BIM is a term that has become ubiquitous in design and construc on fields over the past 20 years. For the purposes of this paper, BIM refers to “a technique u lized by so ware to represent geometry with solid modeling and feature based a ributes to represent both physical and intrinsic proper es of a building.� In addi on most BIM so wares now feature rendering engines, database tools and a programming environment to create parametric components. To be considered a Building Informa on Modeling pla orm, the so ware must incorporate a process of architectural representa on that requires a building be modeled using solid objects and lines to represent shapes and boundary condi ons. The designer of a building can view and interact with the model in threedimensional views as well as orthographic two-dimensional plan, sec ons and eleva on views of the model. As the model is developed and objects change, all other drawings within the project will be adjusted simultaneously. A parametric building modeler will allow the user to create constraints, such as defining the height of a horizontal level. This parameter can then be ed to the height of specified set of walls and be adjusted parametrically, crea ng a rela onal database which is ed to the model’s geometry. This process began in the early 1970s in England and the United States for projects funded by federal governments (Eastman 47). These systems were highly complex for their me and answered a need in the architectural industry to be able to change drawings at mul ple scales and across fragmented drawing sheets. The amount of hours that are necessary for the produc on and change of drawings has decreased steadily over me with the general trend of non-farm labor in the United States since 1964. (Figure 1) The improvement 1
Figure 1 : Construc on & Non-Farm Labor Produc vity Index (1964-2003)
Figure 2 : Example of how Construc ve Solid Geometry (CSG) describes form.
in produc vity has risen in concert with computer technology, which has automated tedious tasks in all disciplines. Some of the earliest programs for architectural representa on used BIM technology, though the systems used to run these programs were prohibi vely expensive for Architecture firms. This combined with the rela vely slow processing speed for personal computers and a steep learning curve for BIM pla orms contributed to a growth in two-dimensional line drawing programs such as AutoCAD and Bentley Microsta on. From the roots of the Semi Automa c Ground Engironment (SAGE) graphical interface and Ivan Sutherland’s 1963 Sketchpad program. Solid modeling programs began to appear using developments in the representa on of geometry in the mid-1970’s (Bozdoc). The two main methods of displaying and recording shape informa on that began to appear in the 1970s and 1980s were Construc ve Solid Geometry (CSG) and Boundary Representa on (BREP) (Winberg). The CSG system uses a series of primi ve shapes, either solids or voids, so that combine and intersect to create the appearance of more complex shapes (Figure 2). This development 2
is especially important in represen ng architectural designs, where intersec ons and subtrac ons are common procedures in describing windows, doors and walls. Processing speeds made CSG a great benefit to programmers describing complex shapes. This graphical improvement as well as the computer science paradigm of Object Oriented Programming (OOP) catalyzed early Building Informa on Modeling research. Seeing buildings through the lens of database contributed to the breakdown of architecture into its cons tuent components. Early programmers made catalogs of typical buildings and their cons tuent parts. The first project to successfully create a Building Database was the Building Descrip on System (BDS). The BDS was the first so ware to describe individual elements that are stored in a virtual library for later retrieval and placement in the model. This program uses a graphical user interface, orthographic, perspec ve views and a sortable database that allows the user to sort informa on categorically by a ributes including material type and supplier. The project was designed by Charles Eastman who was trained as an architect at the UC Berkeley College of Environmental Design and went on to work in computer science at Carnegie Melon University. The earliest jus fica on for a BIM system was born of claims that two-dimensional drawings for
Figure 3 - The image below represents a func on from the GLIDE program and the representa ve geometry. This is fundamentally the same set of processes that happens in todays BIM pla orms absent an interface that obscures the commands which are called to perform a func on.
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construc on are inefficient and cause redundancies of one object represented at several scales. Eastman’s team also cri cized hardcopy drawings for their tendency to decay over me and fail to represent the building as renova ons occur and drawings are not updated. In a moment of extreme prophecy, the no on of automated model review emerges to “check for design regularity” in 1974 (Eastman). Eastman’s project was funded by DARPA, the Defense Advanced Research Projects Agency and was wri en long before the age of personal computers, on a PDP-10 (Figure 4) . Very few architects were ever able to work on the BDS system and its unclear whether any projects were ever realized using the so ware. Though BDS was inaccessible to most architecture firms, Eastman concluded that BDS would reduce the cost of design, through ‘dra ing and analysis efficiencies’ by more than fi y percent. It was an experiment that would iden fy some of the most fundamental problems to be tackled in architectural design over the next fi y years. Eastman’s next project, GLIDE (Graphical Language for Interac ve Design) created in 1977 at Carnegie Melon University exhibited all of the characteris cs of a modern BIM pla orm with the excep on of phased construc on features and me based a ributes. (Eastman). The RUCAPS So ware System developed by GMW Computers in 1986 was the first program to use the concept of temporal phasing of construc on processes and was used to assist in the phased construc on of Heathrow Airport’s Terminal three (Laiserin). The founding of the Center for Integrated Facility Engineering
Figure 4 - The ‘Decision Desktop’ in Building Design Advisor gives a graphical representa on of alterna ve design schemes determined by the user, ed to a BIM model.
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Figure 5 - The PDP-10 computer, used to create the Building Descrip on System at Carnegie Melon.
Figure 6 - ArchiCAD or Radar CH as it was originally known, running on an early Apple personal computer.
(CIFE) at Stanford in 1988 by Paul Teicholz marks another landmark in the development of BIM as this created a wellspring of PhD students and industry collabora ons to further the development of ‘four-dimensional’ building models with me a ributes for construc on. This marks an important point where two trends in the development of BIM technology would split and develop over the next two decades. On one side, the development of specialized tools for mul ple disciplines to serve the construc on industry and improve efficiency in construc on. On the other side is the treatment of the BIM model as a prototype to be tested and simulated against performance criteria. The first appearance of a simula on tool that gave feedback on a range of design schemes based on a BIM model was the Building Design Advisor, developed at Lawrence Berkeley Na onal Lab beginning in 1993 (Papamichael). This so ware u lizes an object oriented model of a building and its context to perform simula ons. It was the first so ware to integrate graphical analysis and simula ons to provide informa on about how the project might perform given alterna ve condi ons regarding the projects orienta on, geometry, material proper es and building systems. The program also includes principles of mathema cal op miza on to make quan ta ve decisions based on a range of criteria which are stored in sets called ‘Solu ons’.
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Virtual Building and Personal Computers While these developments were happening rapidly in the United States, the Soviet Union had two programming geniuses who would end up defining the BIM market as it is known today. Leonid Raiz and Gábor Bojár would go on to be the respec ve co-founder and founder of Revit and ArchiCAD. ArchiCAD arriving in 1982 in Budapest, Hungary behind the Iron Curtain by Gábor Bojár, a Hungarian physicist who rebelled against the communist government and began a private company. Gábor wrote the ini al lines of code by pawning his wife’s jewelry and smuggling Apple Computers through the Iron Curtain (Arnold 2). Using similar technology as the Building Descrip on System, the so ware Radar CH was released in 1984 for the Apple Lisa Opera ng System. Soon a er its second release Radar CH was renamed ArchiCAD. This makes Graphiso ’s ArchiCAD likely to be the first BIM so ware that was made available on a personal computer. The so ware was slow to start as Bojár had to struggle with a unfriendly business climate and the limita ons of personal computers, so ArchiCAD was not used on large scale projects un l much later and was developed mainly as
Figure 7 - Market Share survey from 2007
Figure 8 - Google Trends Showing increasing volume in BIM (Green) Revit (Blue) and ArchiCAD (Red) 6
a tool for developing residen al and small commercial projects in Europe. Recent improvements have made ArchiCAD a major player in the market though fundamental issues such as a lack of a me phasing component and a complicated (but flexible) programming environment for its family components using GDL (Geometric Descrip on Language). To date, Graphiso claims that more than 1,000,000 projects worldwide have been designed using ArchiCAD (Gallello). Not long a er Graphiso began to sell the first seats of ArchiCAD, Parametric Technology Corpora on (PTC) was founded in 1985 and released the first version of Pro/ENGINEER in 1988, a mechanical CAD program that u lizes a constraint based parametric modeling engine. Equipped with the knowledge of working on Pro/ ENGINEER, two lead engineers, Irwin Jungreis and Leonid Raiz split from PTC and started their own so ware company called Charles River So ware in Cambridge, MA. The two wanted to create an architectural version of the so ware that could handle more complex projects than ArchiCAD. They hired David Conant as their first employee, who is a trained architect and designed the ini al interface and user experience. By 2000 the company developed a program called ‘Revit’, a portmanteu of ‘revise it’ which was wri en in C++ and u lized a parametric change engine, made possible through object oriented programming. In 2002, Autodesk purchased the company and began to heavily promote the so ware in compe
on with its own object-based so ware
‘Architectural Desktop’. Revit revolu onized the world of Building Informa on Modeling by crea ng a pla orm with a visual programming environment for crea ng parametric families and allowing for a me a ribute to be added to a element and the ‘fourth-dimension’ of me to be associated with the building model. This enables contractors to generate construc on schedules based on the BIM models and simulate the construc on process. One of the earliest projects to use Revit for design and construc on scheduling was the Freedom Tower project in Manha an. This project was completed in a series of separated but linked BIM models which were ed to schedules to provide real- me cost es ma on and material quan
es. Though the construc on schedule of
the Freedom Tower has been racked with poli cal issues, improvements in coordina on and efficiency on 7
construc on sites catalyzed the development of integrated so wares that could be used to view and interact with architects, engineers and contractors models in overlay simultaneously. There has been a trend towards the composi ng of architectural files with those of engineers who create the systems to support them which has become more prevalent within the past seven years as Autodesk has released versions of Revit specifically for Structural and Mechanical engineers. This increased collabora on has had impacts on the larger industry including a movement away from design-bid-build contracts towards integrated project delivery where many disciplines typically work on a mutually accessible set of BIM models that are updated in varying degrees of frequency. A central file takes an object and applies an a ribute of ownership so that a user who is working on a given project can view all objects but can only change those that they have checked out of a ‘workset’. This enables large teams of architects and engineers to work on one integrated model and makes Revit a form of collabora ve so ware.
CollaboraƟon Fueling BIM Development A broad variety of programs used by architects and engineers makes collabora on difficult. Varying file formats lose fidelity as they move across pla orms, especially BIM models as the informa on is hierarchical and specific. To combat this inefficiency the Interna onal Founda on Class (IFC) file format was developed in 1995 and has con nued to adapt to allow the exchange of data from one BIM program to another. This effort has been augmented by the development of viewing so ware such as Navisworks which is solely designed to coordinate across varying file formats. Navisworks allows for data collec on, construc on simula on and clash detec on. Clash detec on inspects selected objects in a BIM model and checks them against other architect’s or engineer’s models for intersec ons. Following in the footsteps of the Building Design Advisor, simula on programs such as Ecotect, IES, eQUEST and Green Building Studio allow the BIM model to be imported directly and results to be gathered from simula ons. In some cases there are simula ons that are built directly into the base so ware, this 8
method of visualiza on for design itera on has been introduced to Autodesk’s Vasari, a stand alone beta program similar to the Revit Conceptual Modeling Environment where solar studies and insola on levels can be calculated using weather data similar to the Ecotect package. Autodesk, through their growth and acquisi on of a broad variety of so ware related to BIM have contributed to the expansion of what is possible from analysis of a model. However, the business model of buying so ware companies instead of building the companion programs from the ground up means that conceptually the programs do not always match up and results can be highly varied and unreliable unless the operator of the program is an expert in both pla orms. Some have taken a nega ve stance on BIM and parametrics as they limit any work produced to the user’s knowledge of the program. This can enable a teenager who has learned how to perform basic programming tasks to become an incredibly prolific designer while a highly educated and experienced architect can be crippled from inexperience with a programs interface or underlying concepts. This creates a poten al for a genera onal break line, every me a new so ware gains dominance in the market.
Figure 9 - The Grasshopper plug-in for Rhinoceros (created by David Ru en) allows designers to use ‘nodes’ and design scripts in a way that is reminiscent of a flow-chart and easier for non-programmers to understand.
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BIM and the Avant-Garde Some BIM pla orms that have a small market share but have made big impacts on the world of design include Genera ve Components (GC), developed by Bentley Systems in 2003 and Digital Project, developed by Gehry Technologies. Instead of focusing on object-oriented defini ons of walls, doors and windows the GC system is focused on parametric flexibility and sculpted geometry and supports NURBS (Non-Ra onal Uniform B-Spline) surfaces. The interface hinges on a node-based visual scrip ng environment that is similar to VVVV or Grasshopper (Figure 9) to generate forms. Digital Project is a similar program developed by Gehry Technologies around 2006 based on CATIA, a design program that was developed by Dessault systems, a French airplane manufacturer. These two so ware pla orms have spawned something of a revolu on in design as the power to iterate and transform has resulted in especially complex and provoca ve architectural forms. Patrick Schumacher has coined the movement of parametric building models in architecture, specifically those which allow for NURBS surfaces and scrip ng environments as ‘parametricism’ in his 2008 ‘Parametricist Manifesto’. “The current stage of advancement within parametricism relates as much to the con nuous advancement of the a endant computa onal design technologies as it is due to the designer’s realiza on of the unique formal and organiza onal opportuni es that are afforded. Parametricism can only exist via sophis cated parametric techniques. Finally, computa onally advanced design techniques like scrip ng (in Mel-script or Rhino-script) and parametric modeling (with tools like GC or DP) are becoming a pervasive reality. Today it is impossible to compete within the contemporary avant-garde scene without mastering these techniques.”
Since these techniques are highly complex there is now a component of architectural training which is dedicated to developing exper se in specific so ware. A student with knowledge of any par cular pla orm will be influenced by the biases of the program that they are using. By its nature, so ware performs useful tasks by breaking down a procedure into a set of ac ons that have been explicitly designed by a programmer. The programmer takes an idea of what is commonsense (Sack 14) and simulates a workflow using tools available to them to create an idealized goal. In the case of BIM tools, the building is abstracted into ‘elements’ including walls, roofs, floors, 10
windows, columns, etc. These elements have pre-defined rules or constraints which help them perform their respec ve tasks. BIM pla orms represent walls as objects with layers, these layers are defined in terms of the depth and height of a wall and are extruded along the length of a line. The program then has the ability to calculate the volume of material contained within the wall assembly and to create wall sec ons and details easily. This type of workflow is based on the exis ng building stock and common industry standards and therefore a project which is produced in a BIM pla orm which emphasizes categoriza on in this way is likely to reinforce exis ng paradigms rather than develop new ones. Addi onally, the programmers who worked on the early BIM pla orms o en did not have a background in architecture but employed hybrid architect/ programmers who contributed to the development of the programs. One notable excep on I have found to this is the work of Charles Eastman who received a Masters of Architecture from Berkeley before working on the Building Descrip on System. Though the general concept and technology behind BIM is decades old, the industry has only begun to realize the poten al benefits of BIM models. As we reach a point where a majority of buildings are being designed digitally the field of simula on and op mza on will con nue to grow to take advantage of that informa on for the benefit (and possible detriment) of the architect. As experiments in design automa on and benchmarking of models for code/design regularity become more common, the knowledge of the so ware pla orms is becoming even more important if the designer wishes to have autonomy and control beyond the ‘black box’ of complex computa on procedures.
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References
“The Origins of Revit.” AUGI : Autodesk User Group Interna onal. 16 Nov. 2004. Web. 10 May 2011. <h p:// forums.augi.com/showthread.php?t=10925>.
Arnold, J. “High Hopes for Hi Tech.” November 29th, 2002.h p://news.bbc.co.uk/2/hi/business/2522537.stm Gabor Bajar pawns his wifes jewelry for seed money and smuggles Apple computers into Hungary through the Iron curtain.
Bozdoc, Mar an. “The History of CAD”. iMB.
Day, Mar n. Intelligent Architectural Modeling . (www.caddigest.com/subjects/aec/select/Intelligent_ modeling_day.htm) September 2002 Day goes into great detail here explaining the development of RUCAPS, sta ng that it would have cost the equivalent of $200,000 to purchase one seat of the program including hardware. RUCAPS ran on ‘minicomputers’ made by PRIME so its easier to understand why it was the first BIM pla orm that was put into use on a large scale project.
Eastman, Charles, General purpose building descrip on systems. Ins tute of Physical Planning, CarnegieMellon University, Pi sburgh, Pennsylvania 15213, USA - Accepted 8 September 1975.
Eastman, Charles, and Max Henrion. GLIDE : Graphical Language Interac ve for Interac ve Design. SIGGRAPH 1977. Ins tute of Physical Planning, School of Urban and Public Affairs and Department of Architecture, Carnegie-Mellon University, 20 July 1977. Web.
Eastman, Charles. Foreword. BIM Handbook. By Jerry Laiserin. Hoboken: John Wiley & Sons, 2008. 6-9. Print.
Gallello, Dominic. The New Must Have - The BIM Manager. (h p://www.graphiso .com/company/ ontheroad/200712-bim-manager.html) 2007. Web.
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Katz, Neil, Parametric Modeling in AutoCAD . AECbytes Viewpoint #32 (May 16, 2007) (h p://www.aecbytes. com/viewpoint/2007/issue_32.html) Web.
Papamichael, J. LaPorta, et. al. The Building Design Advisor. ACADIA - University of Arizona, 1996
Sack, Warren. User-Friendly, Commonsensical Interface Design. Database Aesthe cs, Victoria Vesna, Editor (Minneapolis, MN: University of Minnesota Press, 2007
Schumacker, Patrik. Parametricism as Style - Parametricist Manifesto.
Winberg, Andres, Dahlqqist, Erik. â&#x20AC;&#x153;BIM - the Next Step in the Construc on of Civil Structures.â&#x20AC;? 2011. KTH Architecture. 31 July 2011
Figure 1 ) h p://www.aecbytes.com/feature/2007/BIMSurveyReport.html - Chart represen ng market share of various BIM pla orms, 2007. Figure 2 ) h p://en.wikipedia.org/wiki/File:Csg_tree.png - Zo e - August 10, 2005 Figure 3 ) Eastman, Charles - GLiDE Graphical Language for Interac ve Design Figure 4 ) Decision Desktop - Building Design Advisor Figure 5 ) PDP-10 Michael L. Umbricht, The Retro-Compu ng Society of RI Original uploader was Sun-collector at en.wikipedia - h p://en.wikipedia.org/wiki/File:PDP-10_1090.jpg Figure 6 ) Apple Personal Computer - ArchiCAD 2.0 - h p://www.archicadwiki.com/ArchiCAD%202.0 Figure 7 ) AEC Bytes - h p://www.aecbytes.com/feature/2007/BIMSurveyReport.html Figure 8 ) Google Trends Figure 9 ) Ru en, David. Grasshopper - McNeel Associates, Rhinoceros 4.0 SR9
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