Does Kentwood, MI need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Kentwood in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Kentwood in the 24th percentile nationally for seismic hazard - higher than 24% of the 4,875 US cities USGS was checked against here.

Kentwood by the numbers

The raw figures: peak ground acceleration 0.043g, short-period spectral response 0.088g, 1-second spectral response 0.047g. Among 153 Michigan cities in this dataset, Kentwood ranks 96 for seismic hazard, the 38th percentile within the state. About 54,768 people live in Kentwood, Michigan.

Bracing and bolting: the actual cost

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Michigan. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

Earthquake insurance for a Kentwood 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 Kentwood address.

More on how this number was built

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