Seattle, you’re likely painfully aware, is due for a really Big One. And, yet, most of the city’s old brick buildings are still not reinforced to modern standards. According to a just-completed report from the city, nearly 20% of Seattle’s unreinforced masonry structures are right here on Capitol Hill, First Hill and in the Central District. The central cluster of 150 buildings is one of the biggest in the city. Below, we’ve mapped the brick buildings using the city’s data showing the few masonry structures that have been retrofitted and the more than 100 in our area alone that will need work.
The Department of Planning and Development “Unreinforced Masonry (URM) Buildings Survey” report completed in July lays it out up front — unreinforced brick is a significant earthquake risk:
Unreinforced masonry buildings have proven over the years and around the world to be the most vulnerable buildings in an earthquake. Two-thirds of the buildings determined to be unsafe to enter immediately following the Nisqually Quake in 2001, were URMs.
URMs are the brick buildings commonly seen in Seattle’s older neighborhood commercial cores, such as in Pioneer Square, Chinatown/International District, Columbia City, Capitol Hill and Ballard. Most of the URMs constructed in Seattle were built before 1940 when seismic reinforcement was not required by the building code. These buildings were originally built without steel reinforcement and with inadequate ties and connections between building elements.
Here’s the map of the city’s survey findings — you’ll note the large pocket of unreinforced masonry structures in Capitol Hill’s core as well as remaining concentrations in downtown, Pioneer Square and smaller pockets elsewhere in the city. You can zoom in and click on specific addresses to learn more. Note that the dataset is heavily caveated by DPD — there may be errors and we have found several funky address issues. If you find anything weird, let CHS know and we’ll see what we can do to further scrub the data.
The data drop from City Hall is part of preparations for a move toward mandating retrofits of brick buildings in Seattle. It’s a move, by the way, that has been crawling forward since well before 2001. The goal now is to have a plan in front of City Council by the end of this year with new legislation in mid-2013.
- Threshold for Retrofit Requirement: We anticipate single family will not be included; should other building types or sizes be excluded?
- Timeline for Compliance: What is a reasonable time period for compliance?
- Penalties and Incentives: What are appropriate penalties for non-compliance? Are there incentives that would encourage upgrades?
- Financing Options: What types of assistance might be available?
As we saw when we mapped the previously available data last year, many of the riskiest buildings were candidates for redevelopment. We profiled one of those buildings here earlier this year.