Does Danville, CA need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Danville is Category D. 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 Danville in the 98th percentile nationally for seismic hazard - higher than 98% of the 4,875 US cities USGS was checked against here.

Danville by the numbers

The raw figures: peak ground acceleration 0.868g, short-period spectral response 2.119g, 1-second spectral response 0.737g. Among 429 California cities in this dataset, Danville ranks 74 for seismic hazard, the 83th percentile within the state. About 43,410 people live in Danville, California.

Bracing and bolting: the actual cost

Because Danville 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 Danville 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 Danville homeowner asking about it.

More on how this number was built

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