Manchester's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Manchester is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Manchester ranks above 50% of the 4,875 cities in this dataset for seismic hazard - the 50th percentile.

Manchester by the numbers

The raw figures: peak ground acceleration 0.079g, short-period spectral response 0.147g, 1-second spectral response 0.044g. Among 46 Maryland cities in this dataset, Manchester ranks 6 for seismic hazard, the 89th percentile within the state. About 5,440 people live in Manchester, Maryland.

Retrofit economics for Manchester

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

Earthquake insurance for a Manchester 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 Manchester address.

More on how this number was built

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