Brighton, CO: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Brighton is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Brighton in the 54th percentile nationally for seismic hazard - higher than 54% of the 4,875 US cities USGS was checked against here.

Where Brighton sits in Colorado

The raw figures: peak ground acceleration 0.094g, short-period spectral response 0.179g, 1-second spectral response 0.054g. Among 79 Colorado cities in this dataset, Brighton ranks 61 for seismic hazard, the 23th percentile within the state. About 43,473 people live in Brighton, Colorado.

Retrofit economics for Brighton

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

What this means for insurance

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 Brighton address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Brighton'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.