Sandpoint's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Sandpoint is 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. That puts Sandpoint in the 74th percentile nationally for seismic hazard - higher than 74% of the 4,875 US cities USGS was checked against here.

Sandpoint by the numbers

The raw figures: peak ground acceleration 0.15g, short-period spectral response 0.334g, 1-second spectral response 0.112g. Among 36 Idaho cities in this dataset, Sandpoint ranks 13 for seismic hazard, the 66th percentile within the state. About 10,444 people live in Sandpoint, Idaho.

What a retrofit costs in Sandpoint

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.

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 Sandpoint address.

More on how this number was built

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