Does Glenwood, IA need an earthquake retrofit?

Glenwood carries Seismic Design Category B under USGS's ASCE 7-16 model. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Glenwood ranks above 18% of the 4,875 cities in this dataset for seismic hazard - the 18th percentile.

How Glenwood compares

The raw figures: peak ground acceleration 0.035g, short-period spectral response 0.072g, 1-second spectral response 0.047g. Among 85 Iowa cities in this dataset, Glenwood ranks 22 for seismic hazard, the 75th percentile within the state. About 5,250 people live in Glenwood, 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 Glenwood address.

More on how this number was built

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