Does Houston, TX need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Houston is Category A. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. That puts Houston in the 12th percentile nationally for seismic hazard - higher than 12% of the 4,875 US cities USGS was checked against here.

How Houston compares

USGS's underlying values for Houston: 0.033g peak ground acceleration, 0.068g at short period, 0.039g at 1 second. Within Texas alone, Houston ranks 220 of 384 cities by seismic hazard - the 43th percentile in-state. Houston has a population of about 2,390,125.

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 Texas 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 Texas.

Insuring against this, not just retrofitting

A Houston 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 Houston's figures come from

Houston'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 Houston.