Clarendon Hills, IL: what USGS's seismic model says

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Clarendon Hills in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Clarendon Hills in the 42th percentile nationally for seismic hazard - higher than 42% of the 4,875 US cities USGS was checked against here.

Clarendon Hills by the numbers

USGS's underlying values for Clarendon Hills: 0.066g peak ground acceleration, 0.129g at short period, 0.065g at 1 second. Within Illinois alone, Clarendon Hills ranks 132 of 330 cities by seismic hazard - the 60th percentile in-state. Clarendon Hills has a population of about 8,703.

What a retrofit costs in Clarendon Hills

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 Illinois 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 Illinois.

Insuring against this, not just retrofitting

A Clarendon Hills 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 Clarendon Hills's figures come from

Clarendon Hills'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 Clarendon Hills.