A bolt-and-brace retrofit anchors a house to its concrete foundation and braces the short wood walls in the crawlspace with plywood, so the house cannot slide off its foundation in an earthquake. It costs roughly $3,000 to $12,000 in Los Angeles and takes one to two weeks. It is the standard retrofit for raised-foundation houses built before 1980.
What gets installed
Anchor bolts or foundation plates every four to six feet along the wood sill plate, square plate washers, plywood sheathing on the short crawlspace walls with a specific nailing pattern, and metal connectors tying the floor framing to those walls. Usually the water heater gets strapped at the same time.
The state grant
California's Earthquake Brace + Bolt program offers up to $3,000 toward a code-compliant retrofit for wood-framed houses built before 1980 on a raised foundation, in participating ZIP codes. There is also a supplemental grant for lower-income households. Registration opens for a limited window each year rather than running continuously, so check the program site for the current window rather than assuming it is open.
Does my house need it
If it was built before 1980, sits on a raised foundation with a crawlspace, and you cannot see bolts through the sill plate or plywood on the short walls, then probably yes. Houses from before the 1950s usually have nothing holding them down at all. We will come look and tell you either way.
Los Angeles County figures, reviewed 2026-10-29 by America General Contractors, California contractor licence CSLB 1083262. Planning ranges, not a quote, and not legal advice. We confirm the current rules for your parcel before anything gets drawn.
