Colonial Heights, VA: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Colonial Heights is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Colonial Heights ranks above 56% of the 4,875 cities in this dataset for seismic hazard - the 56th percentile.

Colonial Heights by the numbers

The raw figures: peak ground acceleration 0.101g, short-period spectral response 0.178g, 1-second spectral response 0.051g. Among 63 Virginia cities in this dataset, Colonial Heights ranks 20 for seismic hazard, the 69th percentile within the state. About 18,674 people live in Colonial Heights, Virginia.

Bracing and bolting: the actual cost

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Virginia. 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 Colonial Heights address.

More on how this number was built

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