Having a central, modifiable and universally available building model in the design and construction process seems like a no-brainer. But cost, training, acceptance and legal liability issues keep the industry from using the technology to its fullest potential.
A three-dimensional model provides an immediate picture to everyone, even those who do not know the industry language necessary to conceptualize traditional design renderings. And building information modeling technology, more commonly known as BIM, eliminates miscommunication, miscalculation and other errors in ways that little else can.
"People are visual. Many times I've been told, 'I have to see it to understand it'; 3-D modeling provides that visual reference that a lot of folks need to understand a project," says Darryl Perrine, computer, design and technical support specialist at LeChase Construction Services LLC.
That expanded understanding allows for more informed decision-making early in the process, which can result in building or energy savings down the line.
It is a little like building with Legos, says Tad Bandurowski, core business leader for Erdman Anthony's facilities business.
BIM uses three-dimensional digital blocks of predetermined size so geometric errors or other inconsistencies can be detected right away, saving time and money with fewer change orders later.
Three-dimensional drawing enables designers to harmonize more easily the structural, mechanical and electrical elements of a building, says Lynn Bellenger, co-founder and partner at Pathfinder Engineers & Architects LLP in Rochester and president of the Atlanta-based American Society of Heating, Refrigerating and Air-Conditioning Engineers.
Says Bandurowski: "When you make your drawings based on a 3-D model, there is almost no room for error."
And a data-rich BIM can be used to generate parts lists, shop drawings and instructions for the fabrication process, Perrine says. In it everything known about the building is captured, providing a consistent source of the most updated information.
"The implications of a moved beam on a duct cannot be detected in a 2-D environment. Now, with BIM, it is possible to detect spatial clashes between the multitudes of complex systems within a building," Perrine says. "You can know with confidence if ductwork will interfere with structural steel long before the start of construction and the arrival of materials."
The ability to detect problems early in the process also means that space is more fully used, Bandurowski says.
The file is password-protected, he says, but anyone with authorized access can view the model to find potential improvements.
For owners, BIM's usefulness goes beyond the project itself. Building owners and operators can keep using the models for energy analysis, space reporting and tenant management, says Brendan Manning, education and environmental director at Albany-based Associated General Contractors of New York State LLC.
Owners, he says, will always have active models, so their staffs can look up which filter to use in an air unit or what type of bulb to order for a light fixture.
All around, BIM allows for substantial savings over the lifetime of a building. The building is more efficient and has a smaller impact on the environment than it otherwise would, says Greg Hale, BIM manager at SWBR Architects.
The transition from traditional drawings to computer-aided drafting occurred gradually over the last 25 years, Hale says. The change was an improvement, but ultimately the output was pretty much the same: a two-dimensional blueprint.
BIM, he says, is basically the next generation of computer-automated building design. In addition to three-dimensional views, today's software programs provide more tools, such as energy analysis, construction sequencing and clash detection.
But the complete transition from traditional drawings to digital design requires a paradigm shift, which is not at all immediate, Perrine says. The hurdles to 100 percent adoption are high and numerous.
To name one, interdisciplinary data sharing is fraught with liability considerations, Bandurowski says. As a result, BIM is making paralegals out of engineers, he says.
"We used to give people a designing intent; that intent was bid or proposed on by the contractors. It really was the duty of the contractor to build the system or the building," Bandurowski says. "With the development of BIM, where you do everything in BIM and in addition you add a lot of information to it, the liability is shifted from the contractor to the owner, which kind of defeats the whole purpose. So to limit their liability, (owners) do not spread those models too eagerly."
What started out as one agency's work, Bellenger says, turns into a file that has everyone's input.
"In that case, you never have total control," she says.
But without an open flow of information, the full benefits of intelligent modeling technology cannot be realized.
Among contractors, BIM's acceptance is strong, Associated General Contractors' Manning says. Nationwide, over 50 percent of the construction industry uses some level of BIM, from full project integration, with architect, engineer and contractor sharing the model, to partial integration, in which access is extended to mechanical, electrical and other trades.
Bandurowski says BIM is perfect for design-build projects, when a builder is doing both design and construction. In that case, the builder already assumes liability for the whole project. (See page 24 for an article on the adoption of the design-build approach.)
"But as far as traditional design-bid-build, BIM helps (the process), but this split of liability between owner, designer and builder has to be sorted out before this technology is fully utilized. That's my opinion," Bandurowski says.
For legal reasons, he says, some of the industry's best designers refuse to use the technology. At the same time, more developers are demanding it, Bellenger says.
"BIM" has become a buzzword, and owners think they need it. The problem is that not all projects can benefit from it.
In some cases, only part of a project would benefit from the tool, such as mechanical rooms or other areas where space is tight and operations are complex. In other cases, the job is just too straightforward to necessitate BIM.
"You could probably describe 100 flavors of BIM," Bellenger says. "What exactly do you mean by the term, and how detailed do you want the information? Are you talking about a rich data set for all of the architectural features; are you talking about being able to turn it over to the contractor afterwards?
"People ask for (BIM) without necessarily exploring what they're asking for, or what level they're asking for, or even how it's going to benefit their specific project," she adds.
Overall, Bellenger is cautionary on the use of BIM, especially because of the costs of software licensing and training as well as problems of program interoperability.
Intelligent modeling technology has no standard yet, which is a key obstacle to information sharing and BIM adoption.
"(There are) multiple types of modeling software in the market that don't necessarily communicate with each other," Manning says. "There are few companies like Autodesk and Bentley that now offer a software that can merge models together, but it's not 100 percent perfect."
But even if there were a common platform for the technology, it still requires high-end computer workstations and expensive software license fees, Hale says.
Software could cost between $2,500 and $4,000 per user, Bellenger estimates. If there are 30 employees, she says, the cost combined with the learning curve may outweigh BIM's potential savings.
And as software updates are made, continued training is required, Hale says. Additional management sometimes is needed to coordinate handling more information and manage work flows.
All of these issues affect BIM acceptance, experts say, and at least for now they provide a strong counterbalance to its benefits.
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