With steel costs rising, city reconsiders wood frames
Daily Journal of Commerce
January 3rd 2008
The Portland Bureau of Development Services this year went against state building codes and approved a handful of mid-rise buildings to be constructed with wood that's not chemically treated for fire protection. The city instead let designers substitute other fire protection measures in exchange for the allowance.
Now, the city says it won't approve anymore un-treated wood-frame buildings over five stories until further notice.
Until recently, steel was the standard building material for structures five or more stories tall.
But over the last five years steel prices have risen to a tipping point where developers can no longer afford to build low-rise buildings with metal frames.
Designers instead are opting for wood frames, which cost less than steel but have different building code requirements from the state.
"It has to do with the market," said Allen Tsai, a project manager for Myhre Group Architects, which is using untreated wood on a five-story apartment project at 14th Avenue and Lovejoy Street in Northwest Portland. "I'd like to go with steel because it's less structurally challenging to go as tall. But because wood is less expensive to build with, that's a developer's choice for a five-to-six-story apartment."
When Oregon's construction standards were based on the Uniform Building Code more than two years ago, designers couldn't substitute wood for steel in five-story buildings. But a state-approved local building code amendment, title 25.95, allowed mid-rise wood frames in Portland.
Few designers took advantage of the code amendment then because steel prices were lower, Hank McDonald, a plan reviewer with the Portland Bureau of Development Services, said.
But in 2005 the state switched from the Uniform Building Code to the International Building Code as the basis for state construction standards and allowed wood-frame buildings over five stories if the lumber was treated with fire resistant chemicals.
Portland's wood-frame code amendment, meanwhile, didn't transfer, and the city hasn't applied to the state for a new amendment.
Still, some Portland designers are playing mix-and-match with old and new building codes, bartering with the city on other fire-protection features to use untreated wood in mid-rise apartments and low-income housing.
The city this year approved designs for five wood-frame five-story buildings but required stricter fire protection measures.
Now the city says it's reluctant to allow more tradeoffs without an in-depth review of the costs and benefits of changing the code.
"The issue is coming at us regularly right now," McDonald said. "(BDS) will rewrite or repeal it so a clear message is being sent."
The Bureau of Development Services today will meet with local builders and architects to consider the need for fire-resistant wood in stick-frame low-rises.