Does Key Biscayne, FL need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Key Biscayne is Category A. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. That puts Key Biscayne in the 0th percentile nationally for seismic hazard - higher than 0% of the 4,875 US cities USGS was checked against here.

Where Key Biscayne sits in Florida

USGS's underlying values for Key Biscayne: 0.018g peak ground acceleration, 0.039g at short period, 0.02g at 1 second. Within Florida alone, Key Biscayne ranks 225 of 228 cities by seismic hazard - the 1th percentile in-state. Key Biscayne has a population of about 15,111.

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 Florida 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 Florida.

Earthquake insurance for a Key Biscayne home

A Key Biscayne 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 Key Biscayne's figures come from

Key Biscayne's Category A 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 A does and doesn't tell you about Key Biscayne.