Ellisville's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Ellisville 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 Ellisville sits at the 82th percentile for seismic hazard among 4,875 US cities.

How Ellisville compares

The raw figures: peak ground acceleration 0.21g, short-period spectral response 0.384g, 1-second spectral response 0.15g. Among 135 Missouri cities in this dataset, Ellisville ranks 48 for seismic hazard, the 65th percentile within the state. About 10,359 people live in Ellisville, Missouri.

What a retrofit costs in Ellisville

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Missouri. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

What this means for insurance

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Ellisville address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Ellisville's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.