North Chicago's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places North Chicago in Seismic Design Category B: 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 North Chicago sits at the 30th percentile for seismic hazard among 4,875 US cities.

North Chicago by the numbers

The raw figures: peak ground acceleration 0.05g, short-period spectral response 0.101g, 1-second spectral response 0.057g. Among 330 Illinois cities in this dataset, North Chicago ranks 310 for seismic hazard, the 6th percentile within the state. About 30,639 people live in North Chicago, Illinois.

Retrofit economics for North Chicago

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.

Earthquake insurance for a North Chicago home

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 North Chicago address.

More on how this number was built

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