Collingdale's Seismic Design Category, explained

Collingdale carries Seismic Design Category B under USGS's ASCE 7-16 model. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Collingdale ranks above 56% of the 4,875 cities in this dataset for seismic hazard - the 56th percentile.

Where Collingdale sits in Pennsylvania

The raw figures: peak ground acceleration 0.1g, short-period spectral response 0.18g, 1-second spectral response 0.047g. Among 193 Pennsylvania cities in this dataset, Collingdale ranks 35 for seismic hazard, the 82th percentile within the state. About 8,956 people live in Collingdale, Pennsylvania.

What a retrofit costs in Collingdale

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

Earthquake insurance for a Collingdale 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 Collingdale address.

More on how this number was built

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