Delafield's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Delafield is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Delafield ranks above 19% of the 4,875 cities in this dataset for seismic hazard - the 19th percentile.

Delafield by the numbers

USGS's underlying values for Delafield: 0.037g peak ground acceleration, 0.075g at short period, 0.048g at 1 second. Within Wisconsin alone, Delafield ranks 47 of 157 cities by seismic hazard - the 71th percentile in-state. Delafield has a population of about 7,275.

What a retrofit costs in Delafield

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 Wisconsin 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 Wisconsin.

Insuring against this, not just retrofitting

A Delafield 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 Delafield's figures come from

Delafield'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 Delafield.