Blythewood's Seismic Design Category, explained

Blythewood 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. That puts Blythewood in the 77th percentile nationally for seismic hazard - higher than 77% of the 4,875 US cities USGS was checked against here.

How Blythewood compares

The raw figures: peak ground acceleration 0.191g, short-period spectral response 0.338g, 1-second spectral response 0.11g. Among 66 South Carolina cities in this dataset, Blythewood ranks 31 for seismic hazard, the 54th percentile within the state. About 6,733 people live in Blythewood, 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 Blythewood 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 Blythewood address.

More on how this number was built

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