Does Franklin, TN need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Franklin in Seismic Design Category D: High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. That puts Franklin in the 80th percentile nationally for seismic hazard - higher than 80% of the 4,875 US cities USGS was checked against here.

Where Franklin sits in Tennessee

The raw figures: peak ground acceleration 0.142g, short-period spectral response 0.287g, 1-second spectral response 0.141g. Among 104 Tennessee cities in this dataset, Franklin ranks 47 for seismic hazard, the 55th percentile within the state. About 89,142 people live in Franklin, Tennessee.

Bracing and bolting: the actual cost

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Tennessee. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

Earthquake insurance for a Franklin 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 Franklin address.

More on how this number was built

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