San Diego, CA Earthquake Safety: Foundation Anchoring (2026)

San Diego's adopted California Residential Code (CRC) Section R602.10.11 and R403.1.6 require foundation plates or sills to be bolted or anchored to the foundation using approved anchor bolts or hold-down connectors. New residential construction must have anchor bolts at maximum 6-foot spacing and within 12 inches of each end of the sill plate, with minimum 7-inch embedment. For existing homes, particularly those built before 1979, seismic retrofit involving foundation bolting and cripple wall bracing is strongly recommended but not mandated absent a permit trigger. The California Earthquake Authority (CEA) sponsors the Earthquake Brace + Bolt (EBB) program, which provides grants of up to $3,000 for qualifying foundation bolt and cripple wall bracing retrofits in select zip codes. San Diego County has several EBB-eligible zip codes. The retrofit involves installing expansion bolts or epoxy bolts through the existing sill plate into the foundation, and adding structural plywood sheathing to cripple walls (the short wood-framed walls between the foundation and first floor). Typical cost for a basic foundation bolt and cripple wall brace retrofit ranges from $3,000-$7,000.