Does Palos Heights, IL need an earthquake retrofit?

Palos Heights carries Seismic Design Category B under USGS's ASCE 7-16 model. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Rank it against the rest of the country and Palos Heights sits at the 40th percentile for seismic hazard among 4,875 US cities.

How Palos Heights compares

The raw figures: peak ground acceleration 0.064g, short-period spectral response 0.127g, 1-second spectral response 0.067g. Among 330 Illinois cities in this dataset, Palos Heights ranks 162 for seismic hazard, the 51th percentile within the state. About 12,088 people live in Palos Heights, 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.

Insuring against this, not just retrofitting

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 Palos Heights address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Palos Heights'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.