Does Simpsonville, SC need an earthquake retrofit?

Simpsonville carries Seismic Design Category C under USGS's ASCE 7-16 model. Moderate seismic hazard. Code adds irregular-building restrictions and requires bracing of some nonstructural components (e.g. tall shelving, water heaters) in addition to structural detailing. Rank it against the rest of the country and Simpsonville sits at the 76th percentile for seismic hazard among 4,875 US cities.

Where Simpsonville sits in South Carolina

The raw figures: peak ground acceleration 0.167g, short-period spectral response 0.291g, 1-second spectral response 0.094g. Among 66 South Carolina cities in this dataset, Simpsonville ranks 42 for seismic hazard, the 37th percentile within the state. About 28,078 people live in Simpsonville, South Carolina.

Bracing and bolting: the actual cost

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

More on how this number was built

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