Does Greenfield, WI need an earthquake retrofit?

Greenfield carries Seismic Design Category B under USGS's ASCE 7-16 model. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Greenfield ranks above 20% of the 4,875 cities in this dataset for seismic hazard - the 20th percentile.

Greenfield by the numbers

The raw figures: peak ground acceleration 0.038g, short-period spectral response 0.077g, 1-second spectral response 0.049g. Among 157 Wisconsin cities in this dataset, Greenfield ranks 33 for seismic hazard, the 79th percentile within the state. About 37,232 people live in Greenfield, Wisconsin.

What a retrofit costs in Greenfield

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