Does Madison Heights, MI need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Madison Heights is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Madison Heights in the 28th percentile nationally for seismic hazard - higher than 28% of the 4,875 US cities USGS was checked against here.

How Madison Heights compares

USGS's underlying values for Madison Heights: 0.047g peak ground acceleration, 0.095g at short period, 0.045g at 1 second. Within Michigan alone, Madison Heights ranks 75 of 153 cities by seismic hazard - the 51th percentile in-state. Madison Heights has a population of about 28,626.

Retrofit economics for Madison Heights

A full earthquake retrofit typically runs $5,000-$10,000 nationally (around $7,000 typical), driven mainly by house size and foundation type, not by Michigan specifically. California's Earthquake Brace + Bolt grant, which covers a large share of this cost, is a California-only program and does not apply in Michigan.

What this means for insurance

A Madison Heights homeowner cannot buy a standalone earthquake policy in most cases - it is added to an existing homeowners policy as an endorsement, so the place to start is a regular home-insurance quote.

Where Madison Heights's figures come from

Madison Heights's Category B and every number above trace to USGS's own ASCE 7-16 Design Maps service - see the methodology guide. See the category explainer for what Category B does and doesn't tell you about Madison Heights.