For many of us in California, our homes are our quiet, safe, and comfortable place. We have spent years pouring time and money into them. The last thing we want is for our space to become unlivable, but that’s exactly what could happen in a big earthquake… if we don’t take steps to prepare to survive and recover.
Earthquake Brace + Bolt (EBB) was developed to help homeowners lessen the potential for damage to their houses during an earthquake. A residential seismic retrofit strengthens an existing older house, making it more resistant to earthquake activity such as ground shaking and soil failure. The seismic retrofitting involves bolting the house to its foundation and adding bracing around the perimeter of the crawl space.
Owners of houses in program ZIP Codes with house characteristics suitable for this type of retrofit in accordance with California Existing Building Code Appendix Chapter A3 (Chapter A3) are eligible for an incentive payment of up to $3,000 to help pay costs associated with the retrofit of their houses.
Most homeowners decide to hire a contractor to do the retrofit work instead of doing it themselves. A typical retrofit may cost between $3,000 and $7,000 depending on the location and size of the house, contractor fees, and the amount of materials and work involved. If the homeowner is an experienced do-it-yourselfer, a retrofit can cost less than $3,000.
Surrounding the crawl space under the ﬁrst ﬂoor, many houses have a short wood framed wall (“cripple wall”) that needs to be strengthened to help prevent the house from sliding or toppling off of its foundation during an earthquake. Seismic Retrofitting involves:
- Bolting: Adding anchor bolts in the crawl space to improve the connection between the wood framing of a building and its concrete foundation.
- Bracing: Adding plywood to the cripple walls to help keep the house from toppling off of the foundation during an earthquake.