Does San Dimas, CA need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, San Dimas 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. Nationally, San Dimas ranks above 96% of the 4,875 cities in this dataset for seismic hazard - the 96th percentile.

How San Dimas compares

The raw figures: peak ground acceleration 0.719g, short-period spectral response 1.689g, 1-second spectral response 0.633g. Among 429 California cities in this dataset, San Dimas ranks 170 for seismic hazard, the 61th percentile within the state. About 33,226 people live in San Dimas, California.

Retrofit economics for San Dimas

Because San Dimas 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.

Insuring against this, not just retrofitting

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 San Dimas homeowner asking about it.

More on how this number was built

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