St. John's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, St. John 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, St. John ranks above 82% of the 4,875 cities in this dataset for seismic hazard - the 82th percentile.

Where St. John sits in Missouri

The raw figures: peak ground acceleration 0.223g, short-period spectral response 0.4g, 1-second spectral response 0.15g. Among 135 Missouri cities in this dataset, St. John ranks 39 for seismic hazard, the 72th percentile within the state. About 6,472 people live in St. John, Missouri.

Bracing and bolting: the actual cost

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 St. John address.

More on how this number was built

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