The NBIMS * list has hosted a conversation on the stages of BIM and how its business deliverables are different from those of CAD. Much of the conversation has focused on stovepipes in the process that reduce deliverables to the lowest common denominator. The discussion originated in how people should estimate time for each of the mileposts in the traditional drawing delivery process. This turned out to be the wrong question.
Early adopters of Building Modeling began creating virtual buildings for the benefits of increased coordination and enhanced visualization. One practitioner noted that over time, he grew to realize that the power of an integrated 3D database went far beyond his initial understanding. Today, it is common to find Owners, Contractors, Subcontractors, and Consulting Engineers around a conference room table in an interactive design exercise; parametric objects are manipulated real time in 3D. This approach leads to consensus building, and, because of the multi-disciplinary buy-in and participation, results in a better working relationship throughout the entire design and construction continuum. Multiple design iterations and 3D visualization are produced for the same fee.
Narratives such as this call into question the traditional mileposts, however hallowed they may be by practice and business process. The traditional deliverable for each milepost is drawings, what one participant derided as “mere black lines on paper.” Another countered that static snapshots will always still be needed to understand building spaces, proportions, intended flow, and relationships between materials....
Every system has its own internal logic and language. “Drafting” is one type of system that has process and tools to support the design and documentation of architecture. “BIM” is another system that has its own internal logic and language for the design and documentation of architecture. “BIM” is a newly designed and evolving system, and will require its own appropriate language, one that articulates the properties of its system.
As I pondered the discussion, I extended it beyond design to construction and the hand-over of data to maintenance and operations. As those hand-offs move beyond “black lines on white paper”, and the exchanges extend beyond those between the designer and the owner, we need new ways to track and measure these exchanges of information. How do we specify and contract for Construction Services to be performed out of the BIM?
- The bidding documents should be BIM. One of the great opportunities for cost reduction is the delivery of a full and accurate bid package, one that requires less fudge factor. This opportunity is lost if the contractor is bidding and building out of the “black lines on paper”.
- The contractor should modify the BIM as the work progresses. All change orders should originate in the BIM. Most firms we work with are willing to walk rather than earn the [too small] payment for delivering as-builts. Building from the BIM, and Change Orders through the BIM is a potential solution.
- Of course, these as-builts should now look like COBIE.
All of this causes wild swings in potential liability—much of it back to the designer.
These changes require new business models, and new standard contracts. They may require educating local contractors about the new process beginning with the initial programming when the decision to use BIM is made.
How would you establish the guidelines and standards for this interaction?
*NBIMS, the National Building Information Model Standard, is a standard for life-cycle data modeling for design, construction, and operation of buildings. NBIMS includes as one of its aspects a standard for Building Modeling to replace CAD as the standard for design and for exchanging information to guide the construction of a building.