Prime Time for BIM
Mark L. Johnson
February 2009Mechanical, electrical and plumbing subcontractors (MEPs) occupy a seat of power. They usually coordinate the materials hanging from a building’s deck and penetrating its ceilings and walls.
"The GCs bring them in early and put them in a big room, where they sit and fight for space,” says John Rapaport, director of operations and general counsel, Component Assembly Systems Inc., a Pelham, N.Y., wall and ceiling contractor. "I make the case that we need to be in the room, too.”
Specifically, Rapaport wants the industry to create BIMs for projects. BIM—Building Information Modeling—is design/data modeling shared by the architect, construction manager, general contractor and the trades. It’s a way to resolve conflicts ahead of construction and allow subcontractors the means to add their two cents—provided they’re invited to participate. Unfortunately, this has largely not been the case with wall and ceiling subs.
The problem is perceptions. Frequently, wall and ceiling contractors are viewed as a project’s low-cost change-order providers. You say HVAC ducts clash with your suspension grid? Well, come on, lower the grid. You learned that some pipes penetrate walls you thought would have no cutouts? Well, cut the holes. It can’t cost that much, can it?
"Historically, 10 percent of the overall job is the carpenter’s work. So, we should be looked at as a prime contractor and should be coordinating early in a design-assist role,” Rapaport says. "The question is, do we get paid for that role? We’re giving up our ‘secrets’—you know, this is how we build, our means and methods and best practices. Can we be comfortable supplying information to create models? Will we get more projects? Will BIM lead to less hard bidding? That’s our goal. We’re not designers, but I think we can be viewed as preferred contractors.”
"CAD on Steroids”
The BuildingSMART Alliance, a program of the National Institute of Building Sciences, Washington, D.C., defines a BIM as a "digital representation of physical and functional characteristics of a facility.”
• A BIM "serves as a shared knowledge resource for information about a facility,” the Alliance says.
• McGraw-Hill Construction’s SmartMarket Report: Building Information Modeling defines BIM simply as "the process of creating and using digital models for design, construction and/or operations of projects.”
• Paul Doherty, AIA, chief technology officer at Satellier, LLC, calls BIM "CAD on steroids.”
It began as basic 3D modeling. But, it’s fast evolving into a system for resolving conflicts, sequencing and scheduling in advance of field work. A BIM captures a building’s design, the objects to be used in construction and specialized data, such as installation sequencing and cost information, all in a single, accessible file. It allows users to place real-world constraints to building objects known as Parametric Design.
"The model has what materials to use, how to attach, dimensions and elements related to sequencing and 4D scheduling,” Rapaport says. "BIM is big. We think there’s 30 to 40 percent waste in this industry; it could be as high as 70 percent.”
Yes, BIM will help eliminate construction inefficiencies. Early data, in fact, show BIM to be quite profitable. McGraw-Hill Construction’s SmartMarket Report: Building Information Modeling surveyed 82 architects, 101 engineers, 80 contractors and 39 building owners during the summer of 2008. Nearly half of the respondents tracked their BIM Return on Investment at a "moderate level or above.”
• Some reported BIM ROIs between 300 and 500 percent on projects where BIM was used.
• Eight of 10 firms reported "improved project outcomes,” which included fewer requests for information and field coordination problems.
• Six to seven of every 10 firms said that BIM had a "positive impact on winning projects.”
"This technology will be the way we do business,” Rapaport says. "It’s how it will be integrated over time, not if. It’s a question of when. I’m hearing that 30 percent of the projects out in the country right now are 3D.”
The Big Push
"We’re seeing a big push toward BIM on all projects,” says Larry Anderson, associate principle, TEECOMM Design Group, an Oakland, Calif., engineering firm specializing in security, telecommunications and audio-visual systems. Anderson says many large general contractors require all members of the construction team to participate in BIM. Electrical, HVAC and plumbing contractors are already involved, and wall and ceiling contractors are next in line.
Actually, some wall and ceiling firms have already worked on BIM-driven projects. For the renovation of Alice Tully Hall at the Julliard School in New York City, for example, Jacobson & Company, Inc., Elizabeth, N.J., avoided as many as 10 conflicts between walls, pipes, ceilings and ductwork. On that project, Turner Construction provided a BIM model. Jacobson created 2D shop drawings and outsourced the 3D BIM renderings and information tagging. That information was then imported into the BIM model of Alice Tully Hall. The conflicts then became apparent, and the Jacobson team was able to work out appropriate solutions.
"People have been kicking the tires,” says Dana K. "Deke” Smith, AIA, executive director, BuildingSMART Alliance, speaking of worldwide acceptance of the BIM process. "Now, we have a new crop of tire-kickers and a lot of people who have made the commitment to use BIM from this point on.”
As with any new technology, the learning curve associated with BIM is a hurdle. Arranging for adequate BIM training is viewed as the greatest challenge to adopting the technology, according to McGraw-Hill Construction’s SmartMarket Report: Building Information Modeling.
The same report showed that potential risks and liabilities associated with BIM technology also exist. For example, errors and inaccuracies in a BIM can result in future change orders and even possible safety issues for owners.
Accountability issues are another area of concern. Since BIM allows for data exchange between architects, engineers and contractors, legal issues can arise over the reliability of the data used in creating the models. "A lot of times, legally, they won’t give you a model until you sign a lot of waivers,” Rapaport says. "That’s because you can’t always rely on the quantities. The architect doing the BIM is not necessarily going to verify what your quantities should be, so you still have to do your own take-off.”
Some contractors worry about sharing trade secrets with any who have access to a common BIM file. "An integrated environment offers considerable advantages to productivity, but team members must hold a greater level of trust in each other,” the McGraw-Hill SmartMarket Report says. "How much of my proprietary information are we going to be able to provide to create the models without the assurance that we’re going to get the contract?” Rapaport asks. "That’s the line over which I think smart owners should act. They should bring in preferred contractors who can model projects, and do so early on.”
Of course, it’s taking time for BIM technology to get up to full speed. "Information is not necessarily flowing as much as I’d like to see it flow,” Smith says. "We are trying to reduce the amount of re-collection of information. We want to collect information once and use it throughout the life of a facility. But I’d say we’re a ways away from getting to that point.”
Software and Specialists
"We hired a BIM specialist to come in and help us,” Anderson says. "The way we were setting up our drawings was killing our computers. We have expensive high-end computers that handle BIM, but you can still overpower them. Anyway, the big thing we heard from architects is that you need to bring in a specialist, somebody who knows what they’re doing.”
What kind of software do you need to open BIM files and contribute to the models? Autodesk has both AutoCAD and Revit Architecture platforms, and Bentley Systems offers the MicroStation—both of which can create modeling files. A product called Autodesk Navisworks enables project design and building professionals to unite their files into a single, synchronized BIM. Finally, software plug-ins are available that allow BIM software to work with standard databases, such as Access, ODBC and Excel.
"What you want to do is take everyone’s models, put them together and figure out the conflicts,” says Bill Johnson, BIM manager at TEECOM.
Basically, BIM software creates pull-down tabs or menus, such as a "Ceilings” pull-down tab, so contactors can view potential conflicts. The software may, for example, number the conflicts—number one, two, three—however many there are. By clicking on a conflict tab, the software zooms in to that area. After that, the GC can call a meeting, often via a Web conferencing session, and together the trades can participate in resolving the conflict. Each subcontractor uploads his proposed solution, modifying the master BIM file, and in this way the construction team avoids costly field delays and reworks. In an ideal world, BIM-enabled projects would allow contractors a way to exert their expertise early in the design process, through a new and developing procedure known as Integrated Project Delivery (IPD).
In IPD, contractors are accorded elevated status as full-fledged design-team members (see InSync on page 00). "The promise of getting my foreman—who has 20 years’ worth of knowledge, or my super, or one of my field guys who really knows what they’re doing—and, early on, having them work together with an architect to design these systems is totally my argument,” Rapaport says. "If you’re going to coordinate, coordinate.”
"Here is the way to take advantage of BIM,” Anderson says. "We’re not quite there yet, but we are starting to show devices in the ceilings of our models. We show public address speakers, security cameras and other things that penetrate the ceilings. At some point soon, ceiling subs are going to be able to say, ‘I know exactly where every single penetration is in every single tile in this whole building.’ They could pre-manufacture these tiles, bring them on site, slap them in place, and every hole will be exactly where it needs to be. That’s the way I see the future going for BIM—everybody cutting costs and being more efficient.”
"Contractors may get the most benefits: managing conflicts, reducing change orders and reducing requests for information,” Smith says. "One issue we’re still wrestling with is that everybody uses the word BIM, but not everybody sees it the same way. We started out with a lot of visualization—and visualization is important. It allows the customer to have a better idea of what they’ll get when it’s delivered. But now what we’re really trying to do is link in sustainability. I think that’s our big challenge for 2009.”
Speaking for wall and ceiling contractors, Rapaport sees paying for the technology as this year’s big issue to resolve. "A lot of public works projects require models to be created, and they want the subcontractors involved in creating models,” Rapaport says. "While some collaboration will happen in the design stage, the driver of the BIM will still be the architect. Should I pay for modeling when I’m not guaranteed to get the project?”
It’s a kind of Catch-22. "Everyone’s convinced the MEP should be modeling, but they’re not convinced the wall and ceiling guy needs to model. They only want my model if I can show them that, by modeling, my work will cost less. Well, that’s very hard to prove,” Rapaport says. "It’s the chicken or the egg. Do a model, and they’ll show you a better way to do your work. Don’t do a model, and they’ll make you do all the change-orders for the others who did do a model. It makes no logical sense.”
That is, the truth be told, the nature of most technology. It is no less true of BIM. While the technology appears to be moving forward, there is nevertheless a lot to sort out.
Mark L. Johnson is an industry writer and marketing communications consultant.