Does Gladstone, MI need an earthquake retrofit?

Gladstone carries Seismic Design Category A under USGS's ASCE 7-16 model. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. Nationally, Gladstone ranks above 1% of the 4,875 cities in this dataset for seismic hazard - the 1th percentile.

Gladstone by the numbers

The raw figures: peak ground acceleration 0.02g, short-period spectral response 0.043g, 1-second spectral response 0.023g. Among 153 Michigan cities in this dataset, Gladstone ranks 152 for seismic hazard, the 1th percentile within the state. About 5,226 people live in Gladstone, Michigan.

What a retrofit costs in Gladstone

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.

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 Gladstone address.

More on how this number was built

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