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.”