Allen's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Allen is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Allen in the 34th percentile nationally for seismic hazard - higher than 34% of the 4,875 US cities USGS was checked against here.

Allen by the numbers

USGS's underlying values for Allen: 0.056g peak ground acceleration, 0.115g at short period, 0.058g at 1 second. Within Texas alone, Allen ranks 50 of 384 cities by seismic hazard - the 87th percentile in-state. Allen has a population of about 113,746.

What a retrofit costs in Allen

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 Allen 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 Allen's figures come from

Allen'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 Allen.