Diving Into BIM
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Walls with generous glazing and ceilings of Douglas fir enclose all of the libraries, including Snoqualmie. Photo: © Yoram Bernet |
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BNB has developed its own document intended for the architects and engineers it works with. The list of 10 pointers, which BNB calls its "rules of engagement," includes a description of what types of information should be incorporated into the model, an outline of acceptable file formats, and suggested methods for managing revisions. One of its tips for designers is to model structural and architectural elements to reflect construction logic. For example, a concrete column for a high-rise building should not be represented as a single element when it is likely to be cast as multiple one-story columns. "The model should reflect how the building is put together," says Dace Campbell, AIA, BNB's integrated project delivery specialist.
With their BIM working methods now well established, neither BNB nor Miller Hull has any interest in returning to traditional 2D CAD. For the contractor, the technology is almost essential to its procurement and construction planning process. So much so that BNB often creates its own digital model when the designers it works with can't provide one. At Miller Hull, all new projects are started in BIM. On a few buildings, the entire consultant team is also using the technology. However, the architect still has some active older projects that rely on traditional documents. Returning to those CAD files, says Coates, "is slightly painful."
| Model Contract Promotes Collaboration and BIM |
The King County Library System decided on design-build delivery for the construction of five of its libraries for small communities outside Seattle. System administrators were keen to control costs, streamline the construction process, and compress the schedule. Another contract model that can offer many of the same benefits is integrated project delivery, or IPD. Proponents say it provides for a more collaborative environment than design-build or design-bid-build, since the main project stakeholders - typically the owner, architect, and the contractor - share risks and rewards. Also, they say, because these parties have a financial interest in a successful outcome, and typically agree to waive claims against each other except under certain circumstances, there is less likelihood that one participant will sacrifice design or construction quality for its own advantage. To date, only a handful of IPD projects have been completed. In order to help spur adoption, the American Institute of Architects (AIA) has created standard contracts, including the C195-2008, Standard Form Single Purpose Entity (SPE), released in May 2008. Under this agreement, the main design and construction team members form a limited liability company (LLC) for the sole purpose of designing and building the project. The newest IPD document, the C191-2009, Standard Form Multi-Party Agreement for Integrated Project Delivery, was released early last month. "Conceptually, C191 is similar to the SPE agreement, but the structure of the business relationships is different," says Ken Cobleigh, managing director and counsel for AIA Contract Documents. Participants do not form an LLC, so they operate as separate entities, he explains. The documents' creators say that the contractual relationships established by the newer agreement should seem more familiar to project participants. The SPE concept is "a little more foreign" to the design and construction industry, says Howard Goldberg, principal of Washington, D.C.-based Goldberg, Pike & Besche, outside counsel to the AIA's documents committee. "Many people were concerned about insurance, bonding, and financing" with the SPE model, he says. One critic of the SPE agreement is William Quatman, FAIA, general counsel at Burns & McDonnell Engineering, Kansas City. He calls the C191 "well thought out" and "detailed." It doesn't present the same licensing and insurance issues as the SPE document "since all the parties play their traditional roles," he says. However, even with the addition of this latest IPD contract, he is uncertain how quickly the delivery system will be embraced. "IPD has to be owner initiated," he says. But advocates for the delivery method say that it can help project teams harness the full capabilities of building information modeling (BIM), which provides a communication conduit and allows a project to be virtually built before construction begins, helping produce better buildings. Although neither C195 nor C191 require a building information model, the contracts' creators did envision that IPD and BIM would be deployed in tandem. According to Goldberg, "BIM without IPD is a little like using a computer only for word processing." J.G. |
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