Does Idaho Falls, ID need an earthquake retrofit?

Idaho Falls carries Seismic Design Category D under USGS's ASCE 7-16 model. 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. Nationally, Idaho Falls ranks above 81% of the 4,875 cities in this dataset for seismic hazard - the 81th percentile.

Idaho Falls by the numbers

The raw figures: peak ground acceleration 0.172g, short-period spectral response 0.399g, 1-second spectral response 0.144g. Among 36 Idaho cities in this dataset, Idaho Falls ranks 7 for seismic hazard, the 83th percentile within the state. About 69,523 people live in Idaho Falls, Idaho.

Bracing and bolting: the actual cost

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

More on how this number was built

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