Red Oak, IA: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Red Oak is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Rank it against the rest of the country and Red Oak sits at the 17th percentile for seismic hazard among 4,875 US cities.

Where Red Oak sits in Iowa

The raw figures: peak ground acceleration 0.033g, short-period spectral response 0.07g, 1-second spectral response 0.05g. Among 85 Iowa cities in this dataset, Red Oak ranks 29 for seismic hazard, the 67th percentile within the state. About 5,420 people live in Red Oak, Iowa.

What a retrofit costs in Red Oak

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

More on how this number was built

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