Does Tolleson, AZ need an earthquake retrofit?

Under the seismic model IBC and ASCE 7 use for new construction, Tolleson is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Tolleson ranks above 49% of the 4,875 cities in this dataset for seismic hazard - the 49th percentile.

Tolleson by the numbers

The raw figures: peak ground acceleration 0.076g, short-period spectral response 0.174g, 1-second spectral response 0.07g. Among 57 Arizona cities in this dataset, Tolleson ranks 53 for seismic hazard, the 7th percentile within the state. About 9,353 people live in Tolleson, Arizona.

Retrofit economics for Tolleson

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Arizona. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

Earthquake insurance for a Tolleson home

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Tolleson address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Tolleson's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.