Winter BIM Forum begins with the Building Envelope, but deals with risk management throughout
While the focus of the Winter BIM Forum in San Diego, Calif., was ostensibly how BIM design and integrated construction could deliver better building envelopes and enclosures, a consistent theme of BIM for risk management showed up in many of the presentations over the two sunny days.
Pat O’Connor, a construction law attorney with the Minneapolis firm Faegre & Benson, and Brian Kramer of Quality Built and Twining, a quality assurance firm, kicked off the BIM Forum by discussing claims made by problem area on construction projects. While several categories included different parts of a building envelope (roofing, 12% of all claims for frequency of failure, for instance) , almost all the ones that could be considered a part of a building enclosure ranked highly on both the frequency and severity of failure scales in O’Connor’s statistics from CNA, the largest professional liability insurer.
“There is a direct correlation between exposure to risk and communication… or lack of it,” O’Connor said. “BIM creates a better platform for collaboration.”
Caption: Pat O’Connor of Faegre & Benson discusses liability issues at the BIM Forum.
This segued into a presentation entitled “Managing Risk through the BIM Model.”
Nathan Wood of DPR Construction showed how BIM was used to identify issues between sub-contractor shop drawings and the architect’s design model for the exterior skin of the Sutter Medical Center Castro Valley project, due to be completed in 2013. The difficulty for DPR, BIM consultant Ghafari Associates and the rest of the Building Team was four different building skin systems and three different installers. For example, 200+ in/out connections were coordinated with rebar and drilled. The precast subcontractor did not originally account for rebar spacing during design. More than 50 of those connections were moved during BIM model coordination.
Many of the coordination and collaboration methods, such as early design meetings with the entire team including subcontractors, were used on other Sutter Health /DPR projects including the California Pacific Medical Center, Cathedral Hill Hospital in San Francisco and Sutter’s Roseland campus, which I wrote about in BD+C in 2008.
This chart shows differences between the design team’s Revit model and sub-contractors’ fabrication models discovered in during design on the Castro Valley Medical Center.
Later in the day, Dace Campbell of BNB Builders showed how his company was using BIM for constructability review of building envelopes. Rather than go through all the projects BNB has modeled in BIM since 2006, Campbell gave attendees a list of BIM enclosure best practices. This was one of the more useful lists of the two-day conference and really brought home some of the commonsense BIM practices for everyone using the technology.
- Build the model first, then add 2D detail.
- Share the model whenever possible; assign responsibility for each part of the model, making sure that there is only one copy of each element, and don’t duplicate elements between disciplines.
- Model accuracy is more important than level of detail, some details can also be shown in 2D or in cross-sections, so don’t weigh the model down with too much detail.
- DO NOT use dimension overrides in the model, which was common practice with 2D drawings. Define good modeling standards and stick to them.
- Include phasing in the model. Structure the model to reflect and support anticipated bid packages.
- Ensure than the model reflects construction techniques, and avoid using modeling shortcuts.
- Publish the model frequently to ensure that everyone has access to the latest version as close to real time as possible.
- Finally, test the model early and often for interoperability, which is still an issue. When sending the model to another member of the Building Team, accompany it with screenshots so that the recipient knows what the model is supposed to look like.
Campbell’s presentation was a welcome “do and do not” list for several attendees struggling with how to get the most out of their BIM usage. More like this, please, BIM Forum. Campbell noted that BNB employs no BIM specialists, and that being familiar with the technology is considered a part of the job at the Seattle-based construction company. This approach, I believe, helps them remember to keep their BIM models as simple as possible and not overmodel.
Some of the other presentations over the two-day conference included a curtainwall study of a major skyscraper in downtown Providence, RI, a modular wall-panel design take-off presentation by JE Dunn, and an automated parametric model generation study for wall panels on New York City’s Beekman Tower by Gehry Technologies.
Attendees also voted on five finalists from the “Delivery Process Innovation” category of the 2011 AIA Technology in Architectural Practice (TAP) BIM Awards. The TAP Committee will take these votes into account in addition to the assessment of AIA-selected jurors when deciding on the winning entry. The winners in all the categories will be announced on May 11 at the TAP conference, just before the AIA 2011 National Convention and Design Exposition in New Orleans.
The next BIM Forum will be June 8 and 9th in BD+C’s sweet home, Chicago! Check back here for the call for presentations and more information.
BIM News: Siemens has made all of its low-voltage power distribution products available as Revit MEP objects on the Autodesk Seek website. The Siemens library of electrical distribution products will be available on the AutoDesk Seek website starting March 15.