Mount Prospect, IL: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Mount Prospect is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Mount Prospect ranks above 36% of the 4,875 cities in this dataset for seismic hazard - the 36th percentile.

Mount Prospect by the numbers

The raw figures: peak ground acceleration 0.059g, short-period spectral response 0.116g, 1-second spectral response 0.061g. Among 330 Illinois cities in this dataset, Mount Prospect ranks 249 for seismic hazard, the 25th percentile within the state. About 55,460 people live in Mount Prospect, 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 Mount Prospect address.

More on how this number was built

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