Grand Haven's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Grand Haven in Seismic Design 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 Grand Haven sits at the 19th percentile for seismic hazard among 4,875 US cities.

Grand Haven by the numbers

The raw figures: peak ground acceleration 0.037g, short-period spectral response 0.076g, 1-second spectral response 0.046g. Among 153 Michigan cities in this dataset, Grand Haven ranks 116 for seismic hazard, the 24th percentile within the state. About 11,045 people live in Grand Haven, Michigan.

Retrofit economics for Grand Haven

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 Grand Haven 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 Grand Haven address.

More on how this number was built

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