Does Harriman, TN need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Harriman 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. Nationally, Harriman ranks above 79% of the 4,875 cities in this dataset for seismic hazard - the 79th percentile.

Where Harriman sits in Tennessee

USGS's underlying values for Harriman: 0.28g peak ground acceleration, 0.443g at short period, 0.117g at 1 second. Within Tennessee alone, Harriman ranks 77 of 104 cities by seismic hazard - the 26th percentile in-state. Harriman has a population of about 6,216.

What a retrofit costs in Harriman

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 Tennessee 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 Tennessee.

What this means for insurance

A Harriman 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 Harriman's figures come from

Harriman'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 Harriman.