Does Marietta, OH need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Marietta is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Marietta in the 32th percentile nationally for seismic hazard - higher than 32% of the 4,875 US cities USGS was checked against here.

Marietta by the numbers

USGS's underlying values for Marietta: 0.054g peak ground acceleration, 0.111g at short period, 0.055g at 1 second. Within Ohio alone, Marietta ranks 238 of 254 cities by seismic hazard - the 6th percentile in-state. Marietta has a population of about 13,039.

What a retrofit costs in Marietta

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 Ohio 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 Ohio.

What this means for insurance

A Marietta 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 Marietta's figures come from

Marietta'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 Marietta.