Does Fort Mill, SC need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Fort Mill in Seismic Design Category C: Moderate seismic hazard. Code adds irregular-building restrictions and requires bracing of some nonstructural components (e.g. tall shelving, water heaters) in addition to structural detailing. Rank it against the rest of the country and Fort Mill sits at the 72th percentile for seismic hazard among 4,875 US cities.

How Fort Mill compares

USGS's underlying values for Fort Mill: 0.117g peak ground acceleration, 0.224g at short period, 0.087g at 1 second. Within South Carolina alone, Fort Mill ranks 64 of 66 cities by seismic hazard - the 3th percentile in-state. Fort Mill has a population of about 36,244.

Retrofit economics for Fort Mill

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 South Carolina 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 South Carolina.

Earthquake insurance for a Fort Mill home

A Fort Mill 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 Fort Mill's figures come from

Fort Mill's Category C 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 C does and doesn't tell you about Fort Mill.