Does Urbandale, IA need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Urbandale 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 Urbandale sits at the 16th percentile for seismic hazard among 4,875 US cities.

Where Urbandale sits in Iowa

USGS's underlying values for Urbandale: 0.029g peak ground acceleration, 0.061g at short period, 0.051g at 1 second. Within Iowa alone, Urbandale ranks 48 of 85 cities by seismic hazard - the 44th percentile in-state. Urbandale has a population of about 47,759.

Retrofit economics for Urbandale

A full earthquake retrofit typically runs $5,000-$10,000 nationally (around $7,000 typical), driven mainly by house size and foundation type, not by Iowa specifically. California's Earthquake Brace + Bolt grant, which covers a large share of this cost, is a California-only program and does not apply in Iowa.

What this means for insurance

A Urbandale homeowner cannot buy a standalone earthquake policy in most cases - it is added to an existing homeowners policy as an endorsement, so the place to start is a regular home-insurance quote.

Where Urbandale's figures come from

Urbandale's Category B and every number above trace to USGS's own ASCE 7-16 Design Maps service - see the methodology guide. See the category explainer for what Category B does and doesn't tell you about Urbandale.