Markham, IL: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Markham is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Markham in the 38th percentile nationally for seismic hazard - higher than 38% of the 4,875 US cities USGS was checked against here.

How Markham compares

USGS's underlying values for Markham: 0.062g peak ground acceleration, 0.125g at short period, 0.067g at 1 second. Within Illinois alone, Markham ranks 211 of 330 cities by seismic hazard - the 36th percentile in-state. Markham has a population of about 11,290.

What a retrofit costs in Markham

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.

Earthquake insurance for a Markham home

A Markham 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 Markham's figures come from

Markham'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 Markham.