Frankfort's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Frankfort is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Frankfort in the 47th percentile nationally for seismic hazard - higher than 47% of the 4,875 US cities USGS was checked against here.

Where Frankfort sits in Indiana

USGS's underlying values for Frankfort: 0.072g peak ground acceleration, 0.149g at short period, 0.079g at 1 second. Within Indiana alone, Frankfort ranks 66 of 126 cities by seismic hazard - the 48th percentile in-state. Frankfort has a population of about 16,459.

Bracing and bolting: the actual cost

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 Indiana 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 Indiana.

Insuring against this, not just retrofitting

A Frankfort 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 Frankfort's figures come from

Frankfort'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 Frankfort.