Designing in 3-D

So-called “clash detection” will not help healthcare executives pick the right tie for their jacket, but it may save them time and money on their organization's next construction project.

Clash detection is one of the functions provided by building information modeling, or BIM, software, and one thing it does is help make sure construction crews aren't handed different sets of designs that accidentally call for putting objects such as heating ducts, support beams or electrical conduits in the exact same place.

Architect Kristine Fallon, president of Chicago-based Kristine Fallon Associates, says BIM provides an information-rich context in which “real-world elements” are used to create a model. For example, instead of just drawing a wall, the wall's materials, thermal properties and paint color can be entered.

Though the ideas behind BIM date back to the 1950s, Fallon says it wasn't commercially available until the mid-1990s and the most widely used program, Revit, now sold by San Rafael, Calif.-based Autodesk, was released in May 2000.

But adoption has been slow. A 2008 survey conducted by the publishers of McGraw-Hill Construction found that adequate training was a key obstacle as was management buy-in and the lack of external incentives or directives to use it.

“There is a slow learning curve,” says Todd Freed, vice president of healthcare at St. Louis-based McCarthy Building Cos. “There are a lot of set skills and shortcuts you need to learn to be proficient.”

But once BIM proficiency is achieved, architects, designers, and engineers can create 3-D models of a project that can result in cheaper, faster and higher-quality construction, says Mark Howell, a vice president and account manager at Skanska USA Building, Seattle.

“I would say it goes further than clash detection—where you make sure a pipe, a beam and a conduit are not sharing the same space,” Howell says. “The next step in 3-D modeling is determining ‘constructability,' or how the pieces come together.”

In the BIM world, scheduling is considered the fourth dimension, and pricing the fifth.

Howell explains that BIM can be used to determine the most cost-effective way or time to cast concrete or erect steel and, in the process, improve planning and avoid the delays caused by reworking sections of the project or waiting for change orders to be approved.

“There are time and cost savings—whether it's from avoiding a clash or finding a better means to build something,” Howell says, adding that the old way of fixing problems—which involved stopping work, writing a request for information, and then waiting for an answer—are over. “Anytime you speed up the flow of information, it's better.”

BIM also helps healthcare organizations, contractors and subcontractors visualize how a project will proceed.

“It can help with sequencing the flow of work with contractors so they can make sure they have materials and labor on hand,” Howell says.

If there are time constraints and the perfect pieces are not available, Howell says BIM helps determine what the possible options are and whether it's feasible to use them.

Determining exactly how much BIM shaves off a construction project's cost isn't feasible, experts say, because to do so would require the construction of two exact structures—one using BIM and one not using it. But Howell thinks his client is saving at least 2% to 5% on the cost of the new $281 million patient tower at the 221-bed MultiCare Good Samaritan Hospital that Skanska is building in Puyallup, Wash. More importantly, however, it will allow the project to be completed in a shorter period of time.

The site was cleared in January 2008, and the nine-story building should have patients moving into its 80 new private rooms and using the operating room suites and diagnostic imaging services around December 2010.

“The schedule is very aggressive for this type of project,” Howell says. BIM “has certainly aided the progress of the job. We just broke ground a year ago, and now the 350,000-square-foot structure is complete. And we're halfway up on bricks. The project is moving rapidly.”

Skanska has a design team at the site, and any changes to the plans are immediately added to the computer model, Howell says, so construction crews have immediate access to the most up-to-date data.

At St. Thomas Health Services' new 555,000-square-foot Middle Tennessee Medical Center in Murfreesboro, near Nashville, Turner Construction Co. is stating that the use of Lean Construction Institute methods facilitated by BIM has resulted in $3 million in savings with one-third of that directly attributed to BIM.

Andy Davis, a senior project manager in Turner's Nashville office, explains that the Lean methods, for example, call for having the proper-sized materials delivered on-site. So if 8-foot-long beams are called for, that's what's delivered—not 9-foot beams that have to be cut on-site.

“Every cut costs money,” Davis says. “With 270 patient rooms—if you reduce one task—that does add up over time.”

For the 270 rooms, Davis says each unit was broken down into 30 numbered pieces and then “we put everything on a pallet and sent it up to the room.”

BIM wasn't used in the early design phases, Davis says, but was used to avoid space clashes for above-the-ceiling elements such as air ducts, medical gas piping, steel structural components, fire protection, plumbing, electrical boxes and light fixtures.

“All ductwork was manufactured off-site, delivered and then just screwed together,” Davis says. “Being able to take BIM and having confidence that what you're making will fit, ultimately allows every system to go in more efficiently and at a much faster pace.”

Davis says his electrical subcontractor is reporting savings of 30% through the use of prefabricated elements. In a project in which construction costs are budgeted at $189 million, savings of $1 million to $3 million may lose some significance, but Davis says the speed of the project will mean the facility can also start producing revenue sooner.

“When the project started three years ago, we were supposed to be done August 2010; now we are committed to be done by June and we're projecting to be done in May,” Davis says, adding that the first day for patients was originally supposed to be Nov. 1, 2010. Now it's Aug. 2, 2010.

In Burlingame, Calif., where Turner is working on a 243-bed, $620 million facility to replace the current 262-bed Mills-Peninsula Medical Center, James Barrett, the company's national director of virtual design and construction, says using BIM and Lean Construction techniques has knocked about $8.5 million off the construction price mostly through off-site prefabrication.

BIM-facilitated prefabrication of building elements also can pay off down the line with infection control, McCarthy's Freed says.

“BIM technology has allowed us to prefabricate 10- to 15-foot pieces of ductwork in a shop that is off-site in a controlled environment—which can be cleaner than a construction site—and where we can integrate the mechanical, electrical, plumbing and fire protection contractors in one facility where they're able to prefabricate systems,” Freed says. “If I were to make a guess, I'd say there'd be hundreds of clashes in all our healthcare projects, but now we're solving them before the project begins.”

Freed says BIM's benefits are often “not something tangible you can identify” with a dollar amount, such as a safer and less cluttered construction site.

“Instead of working on a 10-foot ladder, you're able to work on the ground on something right in front of you,” Freed says, explaining that the need to provide on-site material storage is also reduced, and there is no need for various cutting stations scattered around the site because everything is the proper size when it arrives.

While the Turner project in Murfreesboro utilized “same-handed” rooms, where everything is in the same place in every room, Freed says McCarthy has been able to find savings in “mirror-image” rooms, where common elements are found on either side of the wall. For example, Freed says, complicated two-unit patient head walls are able to be prefabricated off-site and delivered ready to be installed.

“You can begin to imagine all that is improved when it's assembled in a clean, dry off-site shop and delivered,” Freed says. “I don't want to say we made it into building blocks, but these preassembled pieces come in and then it's just plug and play.”

Sometimes BIM also can be used to find the most energy-efficient location or orientation for a building on a given property.

In extreme climates like Arizona, Freed explains that “shade studies” need to be done to determine how much heat a hospital gains through its windows and exterior and then take that in account when designing the heating, ventilation and air-conditioning system.

“BIM allows you to ‘move' the building and do some of those shade studies,” he says. BIM can also be used to complement other technology for more efficient renovations of existing facilities. Freed says someone can “stick their head” into a ceiling cavity and fire a laser scanner that will pick up all the obstructions present in an overhead space.

“We take all the scanned information and we can build a BIM model of the existing construction,” he says. “We then diagnose with our owners what stays, what goes away and we figure out what we can add new.” Again, the savings can be hard to calculate, but Freed says “the faster we can reopen and generate a patient stream, the faster they can generate dollars.”

Freed adds that, when owners take over a hospital, they are given sets of drawings that grow old fast and soon become a maze of red lines and numbers as old parts are replaced or serviced and spaces are renovated. Now, healthcare organizations can receive a 3-D model showing where every valve is located, along with their model numbers and when they need attention, aiding in the development of annual maintenance schedules.

Still, despite the many stated benefits of using BIM, its implementation is far from universal.

Barrett says, at last count, Turner has completed or is working on 125 projects utilizing BIM. About 25% of those projects are healthcare-related, but the biggest project overall is the new $1.2 billion Yankee Stadium. “If you look at the model and look at what was built, they're identical,” Barrett says. “The only time problems arise is when you don't follow the model.”

Utilization of BIM is not standard practice yet, but Barrett says, “You have to make an argument about why you wouldn't be using it now—and it would be a losing argument.”

He blames the lack of use on the size and fragmentation of the construction industry, which make it “hard for new information to be disseminated.”

McCarthy's Freed agrees. “There are different pockets where there are subcontractors who have not fully embraced BIM technology,” Freed says. He recalls working with one subcontractor on a 300,000-square-foot facility and introducing managers to BIM. Freed says the subcontractor was about to start working on a similar-sized hospital and told the owners that if they mandated that everyone on the project use BIM, the subcontractor would promise to return “a couple hundred-thousand” dollars from their bid.

Howell and Freed say the price of BIM systems is not a major issue. Howell prices an advanced system at about $12,000 for each computer in which it's installed. Freed agrees, saying most systems cost $12,000 to $13,000 “a seat,” but some programs like Google SketchUp are available for free, and an advanced version, called Google SketchUp Pro, is available for $495. The Google software is often used in the beginning designs, and the early models are imported into Revit.

“It's a superminor cost,” Freed says. “It is a very small cost because we're saving hundreds of thousands of dollars to our clients.”

It speeds up production, saves money and improves safety, the experts say. And it also produces stunning images and views that can't be captured on paper.

“Certainly, the more complex projects lend themselves to 3-D,” Howell says. “Not many people can look at a two-dimensional drawing and clearly visualize what it will look like. If everyone's working within the model, it's there for you. You can go in and enter at different points and have a virtual walk-through.”