Building Information Modeling (BIM) is rapidly becoming the mainstream design tool in the AEC industry. BIM architecture, though, is not just a tool, but a process, and the very basic, paradigmatic changes this process demands has been slower to be incorporated than the computer-based modeling at the heart of it all.
BIM architecture design as a technology is a fundamental change from the past. CAD-based design is a 2D affair, which necessitated multiple views to depict the 3D building in the detail necessary for construction. Not only that, but CAD drawings in the first iteration are essentially legal, contract documents. The shop drawings, which come next and detail the actual building pieces, are fundamentally redundant. The inherent limitations of this process were several: duplication of work needed to translate 2D to 3D, the increased opportunity for mistakes and errors because of this translation and multiplicity of drawings, and the limited manner in which all these lines, curves and annotations could be aided by computer technology.
BIM architecture design, however, is a 3D, object-based technology. Windows, walls and beams are graphically displayed, but more importantly, embedded with information: parameters, material descriptions, detailing and much more. This information is dynamically linked to all the other objects in the building model, so that changing one piece of a design makes adjustments in all the other connected pieces, allowing for rapid design changes that encourage a more thorough and extensive design process, which, in the end, provides more value to the client.
The embedding of material descriptions and other information in the models makes the documents much more valuable in both the construction and in the life-cycle management phase. The BIM architecture reduction in redundant drawings sharply reduces the possibility of errors in the construction phase and tremendously reduces the time spent on clash detection. It also reduces the incidence of change orders in the construction phase, a huge benefit. The object-based character of BIM architecture allows the design process to include energy, lighting and acoustical analysis in tandem with the structural and spatial design, a radical departure from the traditional post-design analysis that these systems usually get, limiting their effectiveness and possibility. BIM architecture brings changes and efficiencies to every step of the building process, impacting designers, engineers, contractors, fabricators, facility operators, and owners.
The capabilities of the technology we call BIM architecture also is essentially reshaping the entire face of the design team and how project members throughout the building design/lifecycle interact. The "business" of designing, building and maintaining a structure are being radically altered by this new technology. BIM architecture, as a technology, was originally championed by building owners and contractors. The adoption by design professionals was more hesitant, not only because of the radical shift in technology, but the uncertain arena of risk management that BIM's capabilities seemed to thrust upon the front end of the design-build process. By incorporating information from outside sources into a model, there was a worry that design professionals were assuming a far larger share of risk than they were willing. As J. Kent Holland, Construction Risk Counsel puts it:
"The collaboration of contractors and subcontractors in the design has the potential to create uninsurable professional liability risks for themselves, as well as the design professionals, where BIM is used for design and construction of a project. Similarly, the collaboration of the design professionals in the means, methods and procedures of construction has the potential to create uninsured general liability risks for the design professionals. In fact, both professional liability and general liability risks may be difficult to insure in projects where BIM is utilized."
Likewise, the grandiose claims of BIM software makers has produced a climate of inflated expectations that some fear could lead to litigation based upon unrealistic assumptions of what exactly are the "deliverables" in a BIM-based project. It therefore becomes important that in contracts the "level" of BIM be defined. AIA E202 is a fundamental and cautious starting point:
A Building Information Model is a digital representation of the physical and functional characteristics of the project.
Avoidance of overblown promises of comprehensivity or entire building lifecycle expectations are the key here. E202 further provides a very elegant array of "levels" of BIM architecture which define for the owner and builder the precise deliverable the designer intends, providing clarity for the owners/builders and risk mitigation for the designers.
While BIM architecture is the technology driving so much of the change in AEC, it is IPD, Integrated Project Delivery which is the formal mechanism of project organization and procedure which stems from the powerful technological transformations which BIM architecture makes possible. The AIA defines IPD as:
A project delivery approach that integrates people, systems, business structures, and practices into a process that collaboratively harnesses the talents and insights of all participants to optimize project results, increase value to the owner, reduce waste, and maximize efficiency through all phases of design, fabrication, and construction
Functionally, BIM architecture and IPD allow for the welding of owners, designers and contractors into one entity. In fact, in practice, an LLC is often created with these three units which ties their individual financial success to each of the others and waives claims and conflicts between LLC entity partners as far as cost, schedule and defect issues are concerned.
Another method of IPD organization maintains the typical three party agreement but forms an overarching "management group" for decision making.
It is the marriage of BIM architecture and IPD which holds the greatest promise for more efficient, less costly, higher-value project delivery, as front end 3D design incorporates the build stage contractors and information, allowing for design changes to avoid construction errors and change orders. This, of course, is predicated upon owners, designers and contractors breaking out of the old, adversarial ways of thinking and doing business, and embracing the new collaborative scheme which BIM architecture and IPD make possible.
