Boise City's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Boise City 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 Boise City sits at the 73th percentile for seismic hazard among 4,875 US cities.

Boise City by the numbers

The raw figures: peak ground acceleration 0.134g, short-period spectral response 0.303g, 1-second spectral response 0.109g. Among 36 Idaho cities in this dataset, Boise City ranks 21 for seismic hazard, the 43th percentile within the state. About 237,963 people live in Boise City, Idaho.

What a retrofit costs in Boise City

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.

Earthquake insurance for a Boise City 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 Boise City address.

More on how this number was built

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