Does Florissant, MO need an earthquake retrofit?

Florissant carries Seismic Design Category D under USGS's ASCE 7-16 model. 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 Florissant in the 82th percentile nationally for seismic hazard - higher than 82% of the 4,875 US cities USGS was checked against here.

Where Florissant sits in Missouri

The raw figures: peak ground acceleration 0.207g, short-period spectral response 0.376g, 1-second spectral response 0.144g. Among 135 Missouri cities in this dataset, Florissant ranks 49 for seismic hazard, the 64th percentile within the state. About 51,290 people live in Florissant, Missouri.

Retrofit economics for Florissant

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.

Earthquake insurance for a Florissant home

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 Florissant address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Florissant'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.