Does Chicago Heights, IL need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Chicago Heights is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Chicago Heights in the 39th percentile nationally for seismic hazard - higher than 39% of the 4,875 US cities USGS was checked against here.

Chicago Heights by the numbers

USGS's underlying values for Chicago Heights: 0.062g peak ground acceleration, 0.124g at short period, 0.067g at 1 second. Within Illinois alone, Chicago Heights ranks 197 of 330 cities by seismic hazard - the 40th percentile in-state. Chicago Heights has a population of about 26,533.

Bracing and bolting: the actual cost

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.

What this means for insurance

A Chicago Heights 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 Chicago Heights's figures come from

Chicago Heights'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 Chicago Heights.