Norwich's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Norwich 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 Norwich sits at the 57th percentile for seismic hazard among 4,875 US cities.

Where Norwich sits in Connecticut

The raw figures: peak ground acceleration 0.106g, short-period spectral response 0.194g, 1-second spectral response 0.054g. Among 21 Connecticut cities in this dataset, Norwich ranks 16 for seismic hazard, the 25th percentile within the state. About 39,993 people live in Norwich, Connecticut.

Retrofit economics for Norwich

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

Insuring against this, not just retrofitting

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 Norwich address.

More on how this number was built

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