Does Holly Springs, GA need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Holly Springs 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. Nationally, Holly Springs ranks above 73% of the 4,875 cities in this dataset for seismic hazard - the 73th percentile.

Holly Springs by the numbers

The raw figures: peak ground acceleration 0.135g, short-period spectral response 0.246g, 1-second spectral response 0.093g. Among 148 Georgia cities in this dataset, Holly Springs ranks 23 for seismic hazard, the 85th percentile within the state. About 20,133 people live in Holly Springs, Georgia.

Retrofit economics for Holly Springs

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.

Earthquake insurance for a Holly Springs 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 Holly Springs address.

More on how this number was built

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