Kirby's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Kirby in Seismic Design Category A: Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. That puts Kirby in the 6th percentile nationally for seismic hazard - higher than 6% of the 4,875 US cities USGS was checked against here.

Kirby by the numbers

The raw figures: peak ground acceleration 0.024g, short-period spectral response 0.051g, 1-second spectral response 0.023g. Among 384 Texas cities in this dataset, Kirby ranks 340 for seismic hazard, the 11th percentile within the state. About 8,104 people live in Kirby, Texas.

What a retrofit costs in Kirby

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Texas. 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 Kirby address.

More on how this number was built

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