Does Somerville, NJ need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Somerville in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Somerville ranks above 62% of the 4,875 cities in this dataset for seismic hazard - the 62th percentile.

Where Somerville sits in New Jersey

USGS's underlying values for Somerville: 0.149g peak ground acceleration, 0.249g at short period, 0.055g at 1 second. Within New Jersey alone, Somerville ranks 129 of 194 cities by seismic hazard - the 34th percentile in-state. Somerville has a population of about 14,428.

What a retrofit costs in Somerville

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 New Jersey 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 New Jersey.

Insuring against this, not just retrofitting

A Somerville 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 Somerville's figures come from

Somerville'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 Somerville.