Le Mars's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Le Mars is Category A. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. Rank it against the rest of the country and Le Mars sits at the 13th percentile for seismic hazard among 4,875 US cities.

Le Mars by the numbers

The raw figures: peak ground acceleration 0.036g, short-period spectral response 0.076g, 1-second spectral response 0.039g. Among 85 Iowa cities in this dataset, Le Mars ranks 75 for seismic hazard, the 12th percentile within the state. About 10,674 people live in Le Mars, 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.

What this means for insurance

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 Le Mars address.

More on how this number was built

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