Building information modeling replacing computer-aided design

September 5, 2009
Buildings seldom are constructed without encountering some sort of design glitch.

In fact, a 2008 survey from the American Institute of Architects found that one-third of projects are completed behind schedule and over budget, causing building owners to dig deeper into their pocketbooks.

The design-build industry, though, hopes waste will shrink as more architects, engineers and contractors adopt newer 3-D computer modeling that allows more detailed views of a planned building.

The technology, known as building information modeling, or BIM, is produced by several software vendors and represents the biggest change in the construction field since computer-aided design, or CAD, arrived in the late 1980s.

While CAD brought drafting processes into the computer, BIM meshes building models from engineers and architects to integrate information about different building parts, and at what point they will be synchronized and checked for conflicts.

By detecting design discrepancies before construction, designers have a better chance of completing projects on time and on budget, supporters of the technology argue.

Indianapolis-based Turner Construction Company of Indiana LLC used modeling software for the first time when building the Indiana University Simon Cancer Center, the $150 million addition to IU Hospital that opened in August.

Mike Battles, a senior manager at Turner, said 3-D modeling proved particularly beneficial because designers had to match floor-to-ceiling heights and piping with the existing IU Hospital.

Almost real: The software’s ability to make walls and ceilings transparent results in spotting problems earlier in the design process. (Photo Courtesy Schmidt Associates)

“It saved us a huge amount of time in the field because we were able to prefab everything,” he said. “And when we put it together, it was just like we modeled it.”

Indeed, in the traditional drafting process, plumbing and piping inadvertently may accidentally be designed outside of a wall, for instance, or light fixtures above a ceiling. That’s because each subcontractor’s fabrication drawings are layered on top of one another on a light table, to search for conflicts.

The result can be a cumbersome building plan in which the various systems are laid out on different elevations. But BIM technology models actual parts and pieces used to construct a building, and plots their location.

“As you’re modeling building components, you’re doing it in the context of the building itself, which is not how it used to work,” said Greg Hemsptead, an architect at locally based Schmidt Associates. “Now we’re actually putting a pipe where it is located, relative to where a wall is located.”

By doing so, architects, engineers and contractors can reduce errors and deliver better work on a more reliable schedule.

The origins of building information modeling have existed for most of the decade, but architects are beginning to embrace the technology as the benefits become clearer.

A study from industry research firm McGraw Hill Construction forecasts that the proportion of BIM users employing the technology on at least 60 percent of their projects will climb to 45 percent this year from 35 percent in 2008.

Schmidt, the city’s fifth-largest architectural firm in terms of local billings, has employed building information modeling the past two years on seven projects. Those projects include a renovation of the Indiana Historical Society building downtown and the design of an indoor swimming pool at Munster High School.

The firm’s aim is to increase its productivity 20 percent by using the technology on all projects by the end of the year.

Modeling isn’t just for large design firms, however. Indianapolis-based Axis Architecture Interiors LLC, which has eight licensed architects on staff, purchased the software three years ago.

Axis architects used it to design the Indiana headquarters for the Nature Conservancy that is being built at 614 E. Ohio St. using the software on all projects by the end of the year, Managing Partner Drew White said.

“We’re all for it,” he said. “It’s the future of our practice.”

Modeling software typically runs $5,000 to $6,000 for each license but can be purchased for about $1,500 by transferring existing drafting software licenses produced by the same vendor.•


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