Does Superior, WI need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Superior is Category A. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. Nationally, Superior ranks above 1% of the 4,875 cities in this dataset for seismic hazard - the 1th percentile.

Where Superior sits in Wisconsin

The raw figures: peak ground acceleration 0.019g, short-period spectral response 0.041g, 1-second spectral response 0.016g. Among 157 Wisconsin cities in this dataset, Superior ranks 156 for seismic hazard, the 1th percentile within the state. About 26,620 people live in Superior, Wisconsin.

Retrofit economics for Superior

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Wisconsin. 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 Superior address.

More on how this number was built

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