Portland's Seismic Design Category, explained

Portland carries Seismic Design Category D under USGS's ASCE 7-16 model. High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. That puts Portland in the 87th percentile nationally for seismic hazard - higher than 87% of the 4,875 US cities USGS was checked against here.

How Portland compares

The raw figures: peak ground acceleration 0.396g, short-period spectral response 0.875g, 1-second spectral response 0.389g. Among 80 Oregon cities in this dataset, Portland ranks 29 for seismic hazard, the 65th percentile within the state. About 635,749 people live in Portland, Oregon.

Retrofit economics for Portland

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Oregon. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

Insuring against this, not just retrofitting

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Portland address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Portland's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.