jumping on the bim wagon
Model-based design is the biggest change to hit the building industry since CAD, and it means adapting not only to a new technology but also a new way of thinking and working. John Schippers, a designer in the Washington, D.C., office of RTKL, teaches a class on building information modeling at the Washington–Alexandria Center, a satellite campus of Virginia Tech. He provided these tips for firms just starting on BIM.A solid week of training is ideal, but beginners can complete a series of tutorials on their own and then enroll in a two-day training session covering advanced concepts. "It seems like a no-brainer, but I can't tell you how many BIM ventures have failed because people were not properly trained," Schippers says. "They ended up using the software like AutoCAD."Start with a manageable project, preferably one with simple geometries. Smaller is better, both in project and team size. Unlike working in CAD, where team size often doubles or triples in the construction documents phase, BIM teams typically increase only 25 percent to 50 percent.Prepare for more up-front effort. Constructability issues are worked out in schematics and design development—time that's recaptured during the documentation phase. But don't over-detail. Establish standards early on about which components should be modeled and which should be drafted in 2-D. For example, anything that affects dimensional relationships—say, the layers that make up a wall—should be accurately modeled. Such details as sealant joints and flashing can be drafted on top of the model in 2-D later. "It depends on what information you're trying to convey," Schippers says. "If clients want to see cabinetry, I would create a detailed 3-D model, down to the hardware. But the more intricate your model, the more lines the software has to draw, which slows it down."Designate one team member to act as the digital leader on a project, making sure everyone is following the standards and best practices.Perform routine model maintenance. Set a schedule for team members to clean up the model by deleting unused objects and views. Diligent maintenance pays dividends as the amount of information in the model increases.