Does Johns Creek, GA need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Johns Creek 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. Rank it against the rest of the country and Johns Creek sits at the 70th percentile for seismic hazard among 4,875 US cities.

How Johns Creek compares

The raw figures: peak ground acceleration 0.104g, short-period spectral response 0.203g, 1-second spectral response 0.088g. Among 148 Georgia cities in this dataset, Johns Creek ranks 51 for seismic hazard, the 66th percentile within the state. About 81,167 people live in Johns Creek, Georgia.

Retrofit economics for Johns Creek

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.

Insuring against this, not just retrofitting

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 Johns Creek address.

More on how this number was built

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