Grayson's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Grayson is 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. Rank it against the rest of the country and Grayson sits at the 69th percentile for seismic hazard among 4,875 US cities.

Grayson by the numbers

The raw figures: peak ground acceleration 0.093g, short-period spectral response 0.187g, 1-second spectral response 0.085g. Among 148 Georgia cities in this dataset, Grayson ranks 83 for seismic hazard, the 44th percentile within the state. About 5,252 people live in Grayson, Georgia.

What a retrofit costs in Grayson

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

More on how this number was built

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