Louisville/Jefferson County's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Louisville/Jefferson County is 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 Louisville/Jefferson County sits at the 69th percentile for seismic hazard among 4,875 US cities.

Where Louisville/Jefferson County sits in Kentucky

USGS's underlying values for Louisville/Jefferson County: 0.093g peak ground acceleration, 0.19g at short period, 0.098g at 1 second. Within Kentucky alone, Louisville/Jefferson County ranks 26 of 79 cities by seismic hazard - the 68th percentile in-state. Louisville/Jefferson County has a population of about 640,796.

Retrofit economics for Louisville/Jefferson County

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 Kentucky 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 Kentucky.

Insuring against this, not just retrofitting

A Louisville/Jefferson County 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 Louisville/Jefferson County's figures come from

Louisville/Jefferson County'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 Louisville/Jefferson County.