Does North Branch, MN need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, North Branch is Category A. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. That puts North Branch in the 2th percentile nationally for seismic hazard - higher than 2% of the 4,875 US cities USGS was checked against here.

Where North Branch sits in Minnesota

The raw figures: peak ground acceleration 0.021g, short-period spectral response 0.045g, 1-second spectral response 0.023g. Among 155 Minnesota cities in this dataset, North Branch ranks 143 for seismic hazard, the 8th percentile within the state. About 12,258 people live in North Branch, Minnesota.

What a retrofit costs in North Branch

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

More on how this number was built

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