A pitch for metal-frame apartments

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Ankrom Moisan Architects President Tom Moisan has long argued that metal framing is the best way to construct midsize apartment buildings in Portland.

“A lot of sites need more than wood can provide,” he said. “We need urban density. This is how we can get it.”

Moisan believes metal framing is a viable way to erect taller apartment complexes than with wood and at a lower cost than concrete. But not everyone is convinced.

Prefabricated metal-panel framing systems can stifle design creativity and complicate engineering, according to Portland industry professionals who have worked with them. The systems also require careful coordination between architects, contractors and engineers from project conception, professionals say.

“People have been so reluctant to do it in the marketplace because of how proprietary it is and those relationships you have to establish,” said Barry Smith, a Portland-based architect who designed a metal-frame student housing complex near Portland State University.

Nevertheless, Ankrom Moisan has used prefabricated metal-panel framing systems on two apartment projects in Seattle, and is starting to see more interest in the method in the Portland-metro area. The firm’s first Portland project set to use metal framing, Sky3 Place on Southwest Jefferson Street, recently was approved by the Portland Design Commission.

“(Metal framing is) going to take its place as one of the three major construction types,” Moisan said. “We think it’s evolved to the point where we think everybody should look at it.”

Midrange product

Ankrom Moisan recently hosted a seminar on the topic. It was joined by Adolfson & Peterson Construction – a Minneapolis-based company that has developed a prefabricated metal framing system and used it for Seattle apartments. The construction process involves installation of prefabricated wall systems with embedded structural steel tubes that are shipped to the project site.

Joseph Hull, a senior project manager with the Portland office of Adolfson & Peterson, said the company bills its metal framing system as an affordable way to increase density on downtown properties. Wood-frame buildings are cheaper than metal or concrete, but Portland city code limits them to five stories, he said. Concrete doesn’t face those limits, but it’s expensive, he said.

Adolfson & Peterson’s metal framing system typically costs about $160 to $170 a square foot for a standard apartment building 12 to 16 stories, Hull said. A comparable concrete building would cost between $210 and $225 a square foot, he said.

“It’s tough to build a midsized building when your two options are wood and concrete,” he said. “I think these type of systems will revolutionize what downtown buildings look like.”

Potential drawbacks

Myhre Group Architects President Jeff Myhre said that when his firm’s designers have considered metal framing they can’t justify the extra cost above wood, which he said averages about $140 to $150 a square foot.

“We’ve looked at it many times, but it just simply doesn’t pencil out as far as cost,” he said.

The disadvantage of metal framing systems is working with prefabricated parts instead of raw materials, Myhre said.

“That’s the big problem for us as architects and engineers, because every building that we do is custom,” he said. “If you’ve got stock parts and stock connections that don’t offer flexibility, then it’s very hard to design a building.”

A flexible system?

This wasn’t the case for the 15-story Sky3 Place apartments, Ankrom Moisan principal Steve Poland told seminar attendees earlier this month.

“The system was reasonably flexible,” he said. “We didn’t feel it was pushing on what we wanted to do design-wise.”

Amit Kumar, a senior structural engineer with the city of Portland, said the 195-unit apartment complex is the first project in the city he’s seen with this type of metal framing system. Some work was needed to ensure the design would be seismically sound, he said.

“We had some challenges with the structural pieces of it,” he said. “We ended up with a hybrid of the system and using concrete walls.”

Kumar said he doesn’t see a problem with more apartments in Portland being constructed this way.

“As long as they meet the code it’s not an issue,” he said. “Just the material has its limitations.”

During the seminar, Ankrom Moisan associate Michael Willis explained the firm’s use of metal framing for the seven-story, 145-unit Boxcar Apartments completed in 2012 in Seattle. The construction method makes the building feel sturdier, and the floors don’t creak, he said.

“It’s a pretty dense structure,” he said. “It just has a lot of solidity that you don’t usually get with a wood-frame building. It’s just very, very quiet.”

Coordination crucial

Smith said metal framing provided more density in his design for the eight-story, 54-unit MW8 student housing complex at Southwest Fifth Avenue and College Street.

“We had a wood-frame building approved, but we wanted to go higher,” he said.

The MW8 apartments use a different metal framing system than the one developed by Adolfson & Peterson, but Smith said the construction method impressed him enough that he now works as a paid consultant for Adolfson & Peterson.

Smith said he learned with the MW8 project that metal-frame buildings can be constructed quickly only if the architect works closely with the contractor.

“The construction team has to be involved with the design team very early on to make sure they’re not designing something that the system can’t handle,” he said.

Metal-frame buildings are impractical for the traditional design-bid-build format, said Brian Gerritz, president of Portland-based Pavilion Construction, contractor for the MW8 project.

“It tests the deep-rooted conventions of how development works,” he said. “It does require a lot of preplanning, but all that preplanning is why you should be able to deliver in the field.”