Marlborough's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Marlborough is 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 Marlborough sits at the 61th percentile for seismic hazard among 4,875 US cities.

Where Marlborough sits in Massachusetts

USGS's underlying values for Marlborough: 0.146g peak ground acceleration, 0.25g at short period, 0.064g at 1 second. Within Massachusetts alone, Marlborough ranks 29 of 58 cities by seismic hazard - the 51th percentile in-state. Marlborough has a population of about 42,169.

Retrofit economics for Marlborough

A full earthquake retrofit typically runs $5,000-$10,000 nationally (around $7,000 typical), driven mainly by house size and foundation type, not by Massachusetts specifically. California's Earthquake Brace + Bolt grant, which covers a large share of this cost, is a California-only program and does not apply in Massachusetts.

Earthquake insurance for a Marlborough home

A Marlborough homeowner cannot buy a standalone earthquake policy in most cases - it is added to an existing homeowners policy as an endorsement, so the place to start is a regular home-insurance quote.

Where Marlborough's figures come from

Marlborough's Category B and every number above trace to USGS's own ASCE 7-16 Design Maps service - see the methodology guide. See the category explainer for what Category B does and doesn't tell you about Marlborough.