Council addresses unreinforced masonry retrofits for 1,100 buildings

Council addresses unreinforced masonry retrofits for 1,100 buildings

Council addresses unreinforced masonry retrofits for 1,100 buildings

There’s still a lot of work left to be done to ensure that more than 1,000 unreinforced brick masonry buildings in Seattle can withstand a major earthquake, and city councilmembers on Monday identified making sure seismic upgrades don’t displace those most vulnerable among one of their chief concerns.

The city of Seattle has identified 1,100 unreinforced masonry (URM) buildings that represent a life-safety risk should a major earthquake occur, and of those 60 percent have had no retrofit activity to date.

Representative from the Seattle Department of Construction and Inspection and Office of Emergency Management provided the council with an overview of its findings so far on Monday, Oct. 9, as well as an update on recommendations crafted by a policy committee convened in 2012 to explore the issue.

That committee was reconvened in 2016, after an inventory of URMs was compiled by senior structural plans engineer Nancy Devine.

There are 140 URMs in Capitol Hill, 44 in First Hill and 24 in the Central Area.

“They are among the most historic and oldest buildings, and they’re valuable contributors to neighborhood character,” said SDCI director Nathan Torgelson.

Going into URMs that have not had their floors and roofs structurally connected to walls and retroactively reinforcing them to withstand a seismic event is a costly and often lengthy process. The average cost per square foot has been estimated at $45.

OEM director Barb Graff said nine years after the 6.5 magnitude earthquake between Seattle and Tacoma in 1965, the city council approved a retrofit requirement for the Pioneer Square area that was later scrapped due to its extreme financial burden on property owners.

The city is in discussions with the Northwest Insurance Council and banking and mortgage representatives, Graff said, to determine what financing options may be available to minimize the burden of mandatory URM retrofits, which are being recommended by the policy committee.

There are 25,000 people using those 1,100 buildings daily, Torgelson, whether it be residents or commercial tenants, and those most likely to be displaced by a mandatory retrofit policy are low-income and communities of color.

“At the same token, it’s not if, but when we have the next major earthquake occurrence, these buildings could be gone,” he said.

Graff said an assessment of earthquake risk over the next 50 years shows an 86-percent chance of a seismic event similar to the 6.8-magnitude Nisqually earthquake in 2001 and a 12-percent chance of a 9.0 Cascadia event. There are about 700 URMs in Seattle with no significant retrofit work completed, Graff said, and more than 450 of those have at least 100 people in them, or a projected 33,000 people at any given time.

“That’s why this is an urgent issue for us,” she said.

SDCI principal engineer John Siu said even a mild event like Nisqually could cause building parapets to fall, possibly dragging walls with them and reducing support for roof structures. Walls can also bow outward, taking out floors beams and collapsing floors or an entire building.

If the Seattle City Council were to approve making URM retrofits mandatory, parapets would be braced and building roofs, walls and floors would be tied together for what is called a bolts-plus retrofit. Additional bracings would be needed for buildings with thin walls, Siu said, and mortar between bricks also might need replacing on certain structures.

Graff said there are 77 buildings at critical risk, and those are primarily public and private schools. Fire stations have been proactively retrofitted over the years, she said. Seattle Public Schools has been kept updated on the city’s work, Graff said, and is working the potential of mandatory retrofits into its long-term capital budget. There are 21 Seattle schools on the list, as well as 40 buildings owned by the city.

Under the policy committee’s recommendations, critical structures would have seven years to complete a seismic retrofit, which includes one year each for an assessment, permit submittal and permit approval, and then four years to complete the retrofit.

High-risk structures — buildings more than three stories that sit on poor soil, steep slopes and slide areas — would have 10 years, while 902 buildings in the medium-risk category would have 13 years.

If the city council adopts the policy in 2018, all buildings would ideally meet retrofit standards by 2031.

Siu said the policy committee recommendations do not directly identify financing, but the hope is to have some options in place to avoid displacement.

There are more than 5,000 URMs across the state, Graff said.

“So, we firmly believe there should be a state solution that helps fund part of this,” she said.

Creating a more precise statewide inventory of at-risk unreinforced masonry was funded in the state’s capital budget, which the Legislature failed to pass during its 2017 session.

Seattle Councilmember Lorena Gonzalez said she wants real answers in the work plan that addresses reducing displacement risk when developing an ordinance for mandatory retrofits, adding the recommendations put a lot of focus on giving residents and property owners notice.

“That has gotten us into trouble in the past,” she said, “using a notify-heavy approach as a tool to address what we think will be disproportional impacts.”

Graff said city departments will keep applying a racial and social justice lens as they put together financial incentives. She added there are other ideas being worked on, including dedicating an advocate to walk property owners through the retrofit process.

The city requires landlords to provide relocation assistance to tenants who must move from their rental units due to redevelopment and certain code violations. The city also assists with a portion of those costs, which has grown over the years, said Councilmember Lisa Herbold. Knowing the number of residents in affected mixed-use buildings would help determine how much additional funding should be invested into the program, she said. Herbold added the city should think about a policy or incentives for minimizing the time residents are displaced during a retrofit and ensuring they are able to return when the work is finished.

The Great Washington ShakeOut Earthquake Drill is taking place 10:19 a.m. Thursday, Oct. 19, with the Capitol Hill emergency preparedness event occurring in Cal Anderson Park.