Does Harper Woods, MI need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Harper Woods is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Harper Woods in the 29th percentile nationally for seismic hazard - higher than 29% of the 4,875 US cities USGS was checked against here.

Where Harper Woods sits in Michigan

The raw figures: peak ground acceleration 0.049g, short-period spectral response 0.098g, 1-second spectral response 0.045g. Among 153 Michigan cities in this dataset, Harper Woods ranks 57 for seismic hazard, the 63th percentile within the state. About 14,936 people live in Harper Woods, Michigan.

What a retrofit costs in Harper Woods

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Michigan. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

Earthquake insurance for a Harper Woods 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 Harper Woods address.

More on how this number was built

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