Suisun City's Seismic Design Category, explained

Suisun City 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 Suisun City in the 94th percentile nationally for seismic hazard - higher than 94% of the 4,875 US cities USGS was checked against here.

How Suisun City compares

The raw figures: peak ground acceleration 0.641g, short-period spectral response 1.561g, 1-second spectral response 0.545g. Among 429 California cities in this dataset, Suisun City ranks 218 for seismic hazard, the 49th percentile within the state. About 29,614 people live in Suisun City, California.

Retrofit economics for Suisun City

Because Suisun City is in California, the EBB grant applies if the ZIP code participates and the house qualifies (wood-framed house on a raised (not slab-on-grade) foundation, built before 1980): a $3,000-$7,000 bracing-and-bolting job drops to $0-$4,000 after the $3,000 base grant, or effectively free for income-eligible households getting the full $10,000.

Earthquake insurance for a Suisun City home

Earthquake coverage in California mostly runs through the California Earthquake Authority (CEA), sold only through licensed agents at CEA-participating insurers - there is no direct-to-consumer CEA policy. A general home-insurance quote is the practical starting point for a Suisun City homeowner asking about it.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Suisun City's numbers. The retrofit cost and grant guide covers every EBB eligibility rule, including the ones this page can't check.