Concord's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Concord 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 Concord in the 97th percentile nationally for seismic hazard - higher than 97% of the 4,875 US cities USGS was checked against here.

How Concord compares

USGS's underlying values for Concord: 0.775g peak ground acceleration, 1.923g at short period, 0.6g at 1 second. Within California alone, Concord ranks 120 of 429 cities by seismic hazard - the 72th percentile in-state. Concord has a population of about 124,016.

What a retrofit costs in Concord

Cripple-wall bracing and foundation bolting - the scope California's Earthquake Brace + Bolt (EBB) grant funds - typically runs $3,000-$7,000 nationally. Every qualifying household gets a $3,000 base grant, which brings that down to $0-$4,000 out of pocket; income-eligible households ($89,040/year or under) can get up to $10,000 total, covering the retrofit outright in most cases.

What this means for insurance

Concord sits in CEA territory, but CEA earthquake coverage is agent-sold only, never direct - so the real first step for a homeowner here is a standard home-insurance quote, then asking that agent about CEA specifically.

Where Concord's figures come from

Concord's Category D and every number above trace to USGS's own ASCE 7-16 Design Maps service - see the methodology guide. Full Brace + Bolt eligibility rules - beyond what this page can check from a ZIP code alone - are in the retrofit cost and grant guide.