Richton Park, IL: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Richton Park is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Richton Park ranks above 40% of the 4,875 cities in this dataset for seismic hazard - the 40th percentile.

How Richton Park compares

The raw figures: peak ground acceleration 0.064g, short-period spectral response 0.128g, 1-second spectral response 0.068g. Among 330 Illinois cities in this dataset, Richton Park ranks 160 for seismic hazard, the 52th percentile within the state. About 12,504 people live in Richton Park, Illinois.

Bracing and bolting: the actual cost

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Illinois. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

What this means for insurance

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Richton Park address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Richton Park's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.