San Gabriel's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, San Gabriel 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. Rank it against the rest of the country and San Gabriel sits at the 98th percentile for seismic hazard among 4,875 US cities.

San Gabriel by the numbers

The raw figures: peak ground acceleration 0.897g, short-period spectral response 2.061g, 1-second spectral response 0.724g. Among 429 California cities in this dataset, San Gabriel ranks 70 for seismic hazard, the 84th percentile within the state. About 37,926 people live in San Gabriel, California.

What a retrofit costs in San Gabriel

Because San Gabriel 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 Gabriel 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 Gabriel's numbers. The retrofit cost and grant guide covers every EBB eligibility rule, including the ones this page can't check.