From Seattle Daily Journal of Commerce (Seattle, Wash.), April 26, 2012
By Sam Bennett
On the job site, a modular frame building system is put together like Legos
As a contractor, Kim Nakamura likes to call the shots when it comes to constructing a building.
While different size buildings have different requirements for their structural frames, Nakamura says that whenever possible he uses the modular frame building system, also known as MFBS.
A pre-engineered system, MFBS has advantages over a conventional wood-framed system, according to Nakamura, president of Rushforth Construction in Tacoma.
“Every day of the week, I would pick MFBS because of the speed (of construction) and quality,” said Nakamura. “It’s a no-brainer which framing system I’m going with.”
MFBS is patented by Innovative Green Building Systems of Kent. The system includes pre-fabricated frames that are built for tilt-up, bolt together construction, allowing quicker construction.
Innovative Green Building Systems touts the system as termite and pest proof and not susceptible to warping, shrinkage, dry rot, mold or mildew.
Charlie Laboda, senior development manager of Seattle developer Tarragon and a believer in MFBS, said the system is superior to traditional wood-frame on many projects.
“It’s the efficiency of the structure and the contractor’s ability to build it,” said Laboda. “Our marketing (with MFBS) is it’s better than a wood building, and our competition in this product type is going to be a wood building.”
Increased building height is an advantage, too.
Laboda said using MFBS on the 145-unit Boxcar apartments in South Lake Union will allow it to be seven stories, a full story – and 13 apartments – more than a wood-frame building. The project recently broke ground and is scheduled to be finished in 2013.
Laboda said he chose Rushforth for Boxcar because of the company’s expertise in using MFBS. Ankrom Moisan Architects is the designer.
Nakamura first investigated the use of MFBS in 2000 for Thea’s Landing, a five-story apartment/condo project on Tacoma’s Thea Foss Waterway.
Nakamura learned of MFBS too late to use on Thea’s Landing and went with light-gauge steel-frame construction on that project, but he vowed to use MFBS on later projects such as the Panorama skilled-nursing facility in Lacey and the Muriah condo project in Ocean Shores – both of which were completed in recent years.
“It’s the only light-gauge steel-frame system we want to move forward with on any project,” said Nakamura. “It solves a lot of problems.”
In addition to multifamily housing, MFBS can be used for single-family homes, classrooms, and office, retail and light-industrial buildings.
MFBS consists of integrated brace shear panels, gravity load-bearing panels, and window and door panels or headers. The components are prefabricated and welded together from recycled steel tubing, and panels include fasteners, clips and bolts to speed up the erection process.
Blaze Bresko, a structural engineer and principal with Swenson Say Faget of Seattle, said the MFBS is more economical than wood-frame construction.
“We chose the MFBS system for Boxcar for a variety of reasons: the height limit capabilities and ease of panelized construction,” said Bresko. “Framing systems are built much better off-site. The labor and assembly line method that (the Boxcar apartments) will be built with makes it a very economical system. When you’re on-site, it’s like putting together Legos.”
MFBS results in a better acoustical rating, and better thermal properties compared with wood-framed structures, Bresko said. It is essentially a three-part steel system totaling 6 inches in width. The center 3 inches is the structural portion comprised of tube sections that support the building forces. On either side of the 3-inch frame is 20-gauge, 1.5-inch steel furring members that attach to the frame and act as studs. Sheetrock is attached to the studs.
“We feel like 10 stories is a reasonable limit (for MFBS), but more stories are conceivably possible,” said Bresko. “Practical height limits for typical light-gauge steel stud-and-track projects are approximately six stories.”
Bresko said MFBS is about 10 percent more expensive than traditional wood-frame, but the economy of the system – in construction time and thermal benefits – means MFBS will pay for itself over time.
For the Boxcar project, Rushforth used Alliance Steel Fabrication of Tacoma for steel fabrication.
If the system has any challenges, Laboda said it’s planning ahead.
For Boxcar, Laboda considered using wood-frame during design in early 2011. But he brought in Rushforth early enough to arrange the steel fabrication component and the construction schedule met his time-line.
“Kim (Nakamura) requested MFBS right away,” said Laboda. “ You have to know you’re using MFBS early in the game to make sure everything works properly,” he said.