Does Charlotte, NC need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Charlotte in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Rank it against the rest of the country and Charlotte sits at the 57th percentile for seismic hazard among 4,875 US cities.

How Charlotte compares

The raw figures: peak ground acceleration 0.102g, short-period spectral response 0.201g, 1-second spectral response 0.082g. Among 147 North Carolina cities in this dataset, Charlotte ranks 45 for seismic hazard, the 70th percentile within the state. About 943,476 people live in Charlotte, North Carolina.

Retrofit economics for Charlotte

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

More on how this number was built

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