Portland is poised to require posted warnings on brick buildings vulnerable to collapse in a major earthquake.

The signs would read, in at least 30-point type and on a placard no smaller than 8-by-10 inches: "This is an unreinforced masonry building. Unreinforced masonry buildings may be unsafe in the event of a major earthquake."

Landlords would have to send similar notices to building tenants.

City officials say the signs would help visitors and residents make informed decisions about their risk.

Some owners of the buildings -- among them apartment buildings, music venues, restaurants and storefronts -- say the notices would drive away business, making it harder to afford costly seismic retrofits that could address the risk.

Portland has a stock of 1,600 unreinforced masonry buildings that have stood, on average, almost 90 years.

But the West Coast is overdue for a major quake originating from the Cascadia subduction zone, an offshore fault. The odds of a quake with a magnitude of 8 or greater that affects Portland is about 22 to 26 percent in the next 50 years, said Chris Goldfinger, an Oregon State University professor of geology and geophysics.

When the earthquake hits, Portland potentially faces $80 billion in building damage, tens of thousands of people wounded or killed and more than 250,000 residents facing long-term displacement, according to a state report released earlier this year.

California has required such signs for 23 years, though a state commission found in 2004 that only 276 unreinforced brick buildings out of 22,000 statewide complied with the law.

The Portland ordinance comes up for a vote next week. Four city commissioners present Wednesday signaled they would approve it. Commissioner Nick Fish was absent.

The city likely won't require building owners to make fixes to help prevent collapse in a major earthquake for at least 20 years, and the council proposed the placards as an interim measure.

But the building owners said the placards would create a stigma that outweighs the actual risk, and that the signs would drive away customers and renters. The cost could force them to sell to developers who could demolish the buildings, they said.

"It's a false narrative designed to deter business, patrons, tenants and buyers while creating insurance and finance roadblocks," said Angie Even, the owner of an unreinforced masonry building in Southeast Portland.

Other owners argued the city's list of vulnerable buildings is inaccurate and that proving a building should be removed would require a costly and invasive inspection.

The city hasn't retrofitted many of its own vulnerable buildings, and if the ordinance is approved, signs would go up in those buildings Jan. 1.

Other properties would have to post the signs by March 1 with the exception of churches and nonprofit organizations, which would have two years to comply.

The city delayed implementation for churches in part because several pastors from predominantly African American churches that meet in unreinforced brick buildings told the council that they hadn't been invited to discussions about the policy. Several asked the city to back off the placarding mandate altogether.

"There's no way in the world my congregation could go out and buy a million-dollar building right now, because we couldn't afford to pay the loan back," said Bishop Marcus Irving of the Albina Christian Life Center. "We're facing an impossible situation."

-- Elliot Njus

enjus@oregonian.com

503-294-5034

@enjus