By Dave Morningstar

Parsons Electric is among the early adopters of BIM technology. Images provided by M. A. Mortenson Company.

Large building projects are incredibly complex, and the space available for electrical, plumbing, and mechanical services is always limited. Despite the designer’s best efforts, the reality has always been that hundreds, and in many cases thousands, of routing conflicts have to be resolved between the various trades as the building goes up, and that inevitably leads to unplanned downtime and additional cost.

In the industry, these routing conflicts are known as clashes, and until recently they simply have been part of the cost of doing business. But that is changing as computer-based design technologies begin to replace traditional two-dimensional (2D) paper drawings with information-rich, three-dimensional (3D) images.

The technology is based on a Building Information Model, or BIM, which is actually a database containing all of a building’s details in a form that can be accessed and used by advanced Computer Aided Design (CAD) software. BIM technology is both a design tool for the architects, engineers, and trade people who plan the building, and a working tool for the contractors and subcontractors who build it.

Building Information Model (BIM) is a database containing all of a building’s details in a form that can be accessed and used by advanced Computer Aided Design (CAD) software. Images provided by M. A. Mortenson Company.

BIM is a new and rapidly evolving technology in the construction industry. Ideally, the initial electronic model is created by the architect and engineer and delivered to the general contractor who is responsible for integrating design input from all of the trades that will participate in the construction. Each trade, in turn, contributes the details of their tasks to the model to build the complete BIM for the project.

“But, it doesn’t always work out that way,” says Eric Keleny, Design Phase Coordinator for M. A. Mortenson Company. “For a number of practical reasons, architects and engineers have not implemented BIM as quickly as the construction side of the industry. In practice, the pre-fab trades have been the most aggressive in adopting BIM, probably because it has the most immediate payoff for them. Field fabricated and routed trades are not quite as far along, although the leaders in both areas are enthusiastic users of the technology.”

Parsons Electric is among the early adopters of BIM in the routed trades and is working with Mortenson Construction on three large projects using the technology. Each of these projects illustrates a different aspect of BIM implementation.

Sprint Center

Nearing completion for an October opening, the Sprint Center is in downtown Kansas City, Missouri, adjacent to the Power and Light District, a nine-square-block, $835 million, urban redevelopment project that includes the new 19-story H&R Block world headquarters; the Kansas City Live! entertainment block; and major cultural, commercial, retail, and residential projects. It is designed to house professional basketball and hockey teams, arena football, indoor soccer, as well as concerts, circuses, and other events.

The Sprint Center also includes the National Collegiate Basketball Hall of Fame and the College Basketball Experience, both sponsored by the Kansas City-based National Association of Basketball Coaches, whose offices will also be inside the arena. The Hall of Fame, which shares a lobby with the arena, will be a major attraction in its own right and is expected to draw at least 150,000 visitors in its first year.

Chad Knutson is the Parsons’ designer for the Sprint Center, which is thought to be the first large stadium project in the world to utilize BIM technology. Knutson had access to 3D models covering the mechanical and plumbing aspects of the project to reference as he developed the electrical routings.

“We read the engineering data and turned it into a 3D model to route the conduits, place the lighting fixtures, and locate the various electrical panels in the building,” Knutson says. “We shared our files with all of the other trades via Mortenson’s integrated BIM database.” That allowed them to do clash detection on the computer using everyone’s actual installation data.

“On a job like this you would typically expect to resolve literally thousands of clashes in the field. That usually means people are idled while someone negotiates a change, or a meeting is held to resolve the issue. But on this job, the number of field-resolved clashes has been cut to a few dozen that I can recall, and the 3D models made even those relatively easy to resolve. It’s just easier to correct a problem when you’re looking at a 3D image, and that’s what BIM gives us. This is a fast-track project, 18-months from start to finish, and the time we’ve saved in the field using the 3D drawings has really helped us stay on schedule,” Knutson says. “There was a learning curve for me personally, and there is a learning curve for the field electricians because they’re not used to working with 3D images yet.”

Most of Parsons’ work at Sprint Center is being done overhead — installing lighting, communication cabling, and infrastructure support for scoreboards and other stadium-specific equipment. At a second large-scale BIM project, however, the focus was directed underground.

Confidential Data Center

This confidential client’s data center is a 190,000-square-foot building with 45,000 square feet of raised floor space to house computer equipment. It has 25 megawatts of on-site generation capacity as a backup to 10.8 megawatts of UPS power and 14.9 megawatts of Utility Power.

“A data center is a really unique building,” says Ryan Halvorson, a Project Manager for Parsons Electric, “because of the amount of infrastructure that’s installed under the floor”. It takes a lot of coordination due to the amount of cooling to keep a huge room full of computers from overheating, and that means delivering large chilled water lines in 6-foot deep trenches along with large duct banks of redundant electrical power, sanitary and storm sewers, plumbing, and everything else that would be under the floor of a building. We had to request 100 column footings to be dropped up to 10 feet so we could get from point to point with the least amount of conduit bends. There was a lot of coordination and modifications to the design of the building prior to the issuance of construction documents.”

In some places in the Data Center, there are six or seven levels of conduit extending as much as 12 feet below the floor, says Eric Keleny of Mortenson. “There simply isn’t any time available on this job to resolve a large number of clashes in the field, so it had to be done beforehand using the 3D data from BIM.”

“We’ve been coordinating our underfloor routes with plumbing and other trades for more than four months now, and we’ve just broken ground,” Halvorson says. “The first conduit was actually installed on April 2, and the project is scheduled for completion in September 2008. Being able to work in 3D has let us identify and eliminate potential conflicts and clashes ahead of time. We have modeled conduit before, but this is my first experience with a model that includes coordination with the general contractor and the mechanical contractor using BIM technology. I estimate that more than 95 percent of the potential problems were discovered and eliminated during the design and review processes using the 3D imagery. That’s a very, very big deal for us, Mortenson, and the client.”

Large commercial/industrial projects aren’t the only places BIM technology can be applied. Parsons and Mortenson have also collaborated successfully on BIM-based projects where aesthetics were a primary focus.

MacPhail Center for Music

The MacPhail Center for Music, a downtown Minneapolis cultural icon for nearly a century, is building a new $12.5 million facility on the city’s increasingly upscale riverfront. Designed by Twin Cities architect James Dayton, the 58,000-square-foot center will include a performance hall, instruction studios, childhood development classrooms, a large lobby that also serves as a performance space, school offices, a café, and an outdoor performance courtyard.

Excavation for the new, state-of-the-art, 58,000-square-foot MacPhail Center for Music began in fall 2006.

“This is an art and music facility,” says Kent Haiby, a designer for Parsons, “and that means acoustics are the primary concern.” There is special sound attenuation in the ceiling, special materials are used in the walls, and even the exact placement of lighting fixtures is determined largely by acoustic considerations. All of that made the job very complex. Because of the complexity and high visibility, Mortenson decided to make this a BIM project early on. “We received the building in 3D, and then placed all of our conduit runs and lighting above the ceiling and returned the data to Mortenson, who performed the clash testing.”

“Obviously, there were some conflicts, but most of them were resolved during the design stage. Some of the luminaire housings we used were deeper than normal, and that meant we had to do some adjustment of the mechanicals in the space above the ceiling. Normally, everyone abides by an unwritten rule that the first six to eight inches of space above the ceiling belongs to the electrical infrastructure, but the deeper housings infringed on the mechanical contractor’s space.

“With the BIM technology and clash testing we discovered conflicts earlier, discussed them, and resolved them while the building was still just glowing phosphors on a computer display. This is a great coordination tool.”

Lessons Learned and a Look to the Future

And although professionals are singing BIM’s praises, they do offer a warning. “There is no doubt BIM can help us do a better job for our clients, and we are actively investigating ways to let the computer do more of the routine work on all of our projects,” Haiby says. “But you still need an experienced designer to supervise the process and monitor the details — computers are not perfect. For example, putting a decimal in the wrong place when you’re sizing lighting loads could tell you a 200 watt circuit is really a 2,000 watt circuit, or vice versa. You still need a human in the loop who knows what he or she is doing, and what they’re looking at.”

Eric Keleny echoes Haiby’s observation. “If you let the computer do its thing without someone with practical experience supervising it, you are quite likely to end up with nothing more than a bunch of pretty pictures — nice to look at, but useless on the jobsite.”

The images are also useless if not everyone knows what to do with them. “You also have to remember that 3D representations are not something the average electrician, or any other trades person for that matter, is used to dealing with,” Knutson says. “There is a learning curve to this technology, and that means in some cases it could actually add time to a particular job until everyone gets up to speed. In the end, though, there is no question in my mind that it’s worth the effort.”

The learning curve applies on the front end as well. “Designers have to learn to use the technology that generates the 3D images, just like electricians have to learn how to interpret those images,” Haiby says. “But there is more to BIM than simply generating 3D images, and it’s usefulness as a collaboration tool may well be as important as its ability to detect and avoid clashes. We held regular online coordination meetings during the MacPhail Center project. Not only did that save a lot of travel time, it also allowed people who might not have been involved in a normal project to observe and participate.

“For example, I think it would have been very worthwhile for new designers or engineers to sit in on these sessions to see firsthand exactly what’s on the other side of the ceiling tile in a project like this.”

Halvorson says while BIM is no doubt a benefit, it does have its limitations. “The technology is still a bit project-specific,” he says. “The benefits on a big, complex project like a data center or stadium are obvious, but I wonder at what level of complexity BIM will be useful on.”

As for the future, everyone involved in these projects agrees that BIM technology will play an ever-growing role in the construction industry. Whether it will be 3D images displayed on a wireless laptop, or some entirely new technology, the days of 2D paper plans are numbered as technology revolutionizes yet another industry.