Haddonfield's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Haddonfield is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Haddonfield in the 55th percentile nationally for seismic hazard - higher than 55% of the 4,875 US cities USGS was checked against here.

Haddonfield by the numbers

USGS's underlying values for Haddonfield: 0.097g peak ground acceleration, 0.176g at short period, 0.047g at 1 second. Within New Jersey alone, Haddonfield ranks 162 of 194 cities by seismic hazard - the 17th percentile in-state. Haddonfield has a population of about 12,707.

What a retrofit costs in Haddonfield

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 Haddonfield 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 Haddonfield's figures come from

Haddonfield'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 Haddonfield.