Florence's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Florence is 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 Florence in the 96th percentile nationally for seismic hazard - higher than 96% of the 4,875 US cities USGS was checked against here.

Florence by the numbers

The raw figures: peak ground acceleration 0.71g, short-period spectral response 1.411g, 1-second spectral response 0.74g. Among 80 Oregon cities in this dataset, Florence ranks 5 for seismic hazard, the 95th percentile within the state. About 9,504 people live in Florence, Oregon.

Retrofit economics for Florence

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

Earthquake insurance for a Florence 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 Florence address.

More on how this number was built

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