Central City's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Central City 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 Central City in the 81th percentile nationally for seismic hazard - higher than 81% of the 4,875 US cities USGS was checked against here.

Where Central City sits in Kentucky

The raw figures: peak ground acceleration 0.194g, short-period spectral response 0.372g, 1-second spectral response 0.161g. Among 79 Kentucky cities in this dataset, Central City ranks 10 for seismic hazard, the 88th percentile within the state. About 5,744 people live in Central City, Kentucky.

What a retrofit costs in Central City

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

Insuring against this, not just retrofitting

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 Central City address.

More on how this number was built

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