Brighton's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Brighton is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Brighton in the 27th percentile nationally for seismic hazard - higher than 27% of the 4,875 US cities USGS was checked against here.

How Brighton compares

The raw figures: peak ground acceleration 0.046g, short-period spectral response 0.094g, 1-second spectral response 0.046g. Among 153 Michigan cities in this dataset, Brighton ranks 84 for seismic hazard, the 45th percentile within the state. About 7,933 people live in Brighton, Michigan.

Retrofit economics for Brighton

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 Brighton 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 Brighton address.

More on how this number was built

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