Tega Cay's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Tega Cay in Seismic Design Category C: 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. That puts Tega Cay in the 71th percentile nationally for seismic hazard - higher than 71% of the 4,875 US cities USGS was checked against here.

Where Tega Cay sits in South Carolina

The raw figures: peak ground acceleration 0.116g, short-period spectral response 0.222g, 1-second spectral response 0.086g. Among 66 South Carolina cities in this dataset, Tega Cay ranks 65 for seismic hazard, the 2th percentile within the state. About 14,294 people live in Tega Cay, 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.

Earthquake insurance for a Tega Cay home

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 Tega Cay address.

More on how this number was built

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