Friendswood's Seismic Design Category, explained

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

Friendswood by the numbers

USGS's underlying values for Friendswood: 0.032g peak ground acceleration, 0.066g at short period, 0.038g at 1 second. Within Texas alone, Friendswood ranks 239 of 384 cities by seismic hazard - the 38th percentile in-state. Friendswood has a population of about 41,291.

Retrofit economics for Friendswood

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 Friendswood 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 Friendswood's figures come from

Friendswood'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 Friendswood.