Warren's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Warren in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Warren ranks above 28% of the 4,875 cities in this dataset for seismic hazard - the 28th percentile.

Where Warren sits in Michigan

The raw figures: peak ground acceleration 0.047g, short-period spectral response 0.096g, 1-second spectral response 0.044g. Among 153 Michigan cities in this dataset, Warren ranks 70 for seismic hazard, the 55th percentile within the state. About 137,686 people live in Warren, 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.

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 Warren address.

More on how this number was built

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