Does Sheldon, IA need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Sheldon in Seismic Design Category A: Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. Nationally, Sheldon ranks above 12% of the 4,875 cities in this dataset for seismic hazard - the 12th percentile.

Sheldon by the numbers

The raw figures: peak ground acceleration 0.033g, short-period spectral response 0.07g, 1-second spectral response 0.037g. Among 85 Iowa cities in this dataset, Sheldon ranks 77 for seismic hazard, the 10th percentile within the state. About 5,584 people live in Sheldon, Iowa.

Bracing and bolting: the actual cost

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.

Earthquake insurance for a Sheldon 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 Sheldon address.

More on how this number was built

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