Does Greenfield, MA need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Greenfield in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Greenfield in the 54th percentile nationally for seismic hazard - higher than 54% of the 4,875 US cities USGS was checked against here.

Greenfield by the numbers

The raw figures: peak ground acceleration 0.092g, short-period spectral response 0.177g, 1-second spectral response 0.059g. Among 58 Massachusetts cities in this dataset, Greenfield ranks 45 for seismic hazard, the 23th percentile within the state. About 17,633 people live in Greenfield, Massachusetts.

What a retrofit costs in Greenfield

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Massachusetts. 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 Greenfield address.

More on how this number was built

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