Centennial's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Centennial in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Centennial ranks above 59% of the 4,875 cities in this dataset for seismic hazard - the 59th percentile.

How Centennial compares

The raw figures: peak ground acceleration 0.114g, short-period spectral response 0.207g, 1-second spectral response 0.057g. Among 79 Colorado cities in this dataset, Centennial ranks 40 for seismic hazard, the 50th percentile within the state. About 108,853 people live in Centennial, Colorado.

Retrofit economics for Centennial

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.

Earthquake insurance for a Centennial 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 Centennial address.

More on how this number was built

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