Silverton's Seismic Design Category, explained

Silverton 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. Rank it against the rest of the country and Silverton sits at the 86th percentile for seismic hazard among 4,875 US cities.

How Silverton compares

The raw figures: peak ground acceleration 0.354g, short-period spectral response 0.773g, 1-second spectral response 0.374g. Among 80 Oregon cities in this dataset, Silverton ranks 52 for seismic hazard, the 35th percentile within the state. About 10,391 people live in Silverton, Oregon.

Retrofit economics for Silverton

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.

Earthquake insurance for a Silverton home

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 Silverton address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Silverton'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.