Looking for Unreinforced Masonry Buildings on Bainbridge Island

Looking for Unreinforced Masonry Buildings on Bainbridge Island

A team of volunteers accompanied by seismic experts went out on the streets of Bainbridge Island this past fall to look for Unreinforced Masonry Buildings (URMs) that could become dangerous during an earthquake. This is part of an effort to test out a new guidebook that teaches communities how to do sidewalk surveys and build inventories of these structures in their community.

The Bainbridge Island survey follows efforts in Tacoma and Everett in recent years to work with local communities to identify their Unreinforced Masonry Buildings. These previous surveys helped craft the URM Building Survey Workflow Guidebook, which was produced by Cascadia Region Earthquake Workgroup (CREW). The Bainbridge Island survey is the first to utilize the state's newly developed URM survey application that all jurisdictions will be able to utilize moving forward.

"Most small jurisdictions don't have a lot of time or ability to do a thorough inventory," said Maximilian Dixon, the hazards and outreach program supervisor. "That's why this guidebook is important and our partnerships are important. With these surveys and data local governments provide, we can create the scope of the URM problem, understand how big of a problem this is, where it's concentrated and look into how are we going to get funding for this. It's much more difficult to push for funding if we don't have evidence of the problem."

Back in 2018, the state Legislature provided some funding to the Department of Commerce to conduct a survey of Washington's URMs. State agencies collaborated to review 15,200 buildings statewide and used existing data on these structures to identify about 4,300 as confirmed or potential URM buildings and another 2,200 as unknown. However, this survey was just the start of this endeavor. Washington EMD and the Department of Archaeology and Historic Preservation (DAHP) have been working with many partners across the state to build out a more robust process, and develop the tools needed to support this, including a statewide surveying tool, and a centralized URM database.

"We don't know when the next earthquake will be, but we know these buildings will not perform well," said Riley McNabb, earthquake program outreach coordinator with WA EMD. "We want to identify them and get them seismically retrofitted to save lives and preserve these historic structures."

McNabb said the portal could be ready for public viewing at some point in 2026. Information on these buildings is still being gathered and entered.

"Seismic retrofits are expensive, so we don't we want to just present folks with a problem. We want to give them information on what to do next," she said. "We want this information on URM structures to inform and improve communities' preparedness, mitigation, and response planning."

For Pascal Schuback, the executive director of CREW, the issue of URMs on Bainbridge Island is a personal one because it's where he and his family live. He has focused his career on helping his community to be better prepared.

"When we know where the URMs are, we will know those buildings will likely have damage after an earthquake and we can concentrate our resources there after a disaster," he said. "On a hot sunny day on a Saturday, those buildings could all be full of people."

On Bainbridge Island, after a few hours of training, team members split up into groups and scoped out a couple of dozen potential URM buildings in downtown Bainbridge Island.

Groups inspected buildings to see if it was made with bricks, concrete blocks, hollow clay tile, stone, or of some other material. Is the building on a sloping hillside? Does the building show signs of some seismic retrofit already?

"We look to see how these buildings are being used and where there might be more risk," McNabb said. "If one URM building currently houses 30 people and another URM is a vacant building, that can inform which building a community might prioritize retrofitting first."

Groups looked for anchor plates - oftentimes decorative, floral plates called "rosettes" - as these indicate some level of seismic retrofit. They also checked to see if buildings had parapets - wall features that extend beyond a building's roofline - as these can be dangerous in an earthquake if not properly braced.

"Window arches are also a good indicator of URM construction," McNabb told volunteers. "While these arches can indicate high risk, they are also beautiful features that give buildings a lot of character."

This survey was completed entirely on the streets and sidewalks. While these surveyors aren't required to be licensed engineers, they are trained on how to identify these features beforehand, and this data will be then reviewed and verified by credentialed volunteers later.

"For CREW, we work with a lot of communities across the West Coast so a lot of communities are benefiting from this work and this environment," Schuback said. "And this is a great process to bring communities together."

Learn more about URMs.

Check out the CREW URM Guidebook.