What Is a Seismic Retrofit and Does My San Jose Home Need One in 2025?

Quick Answer: A seismic retrofit (also called “bolting and bracing”) is the process of strengthening an existing home’s connection between the foundation and the wood framing above it to reduce earthquake damage risk. Most San Jose homes built before 1980 were not built to modern seismic standards and can benefit from a seismic retrofit costing $5,000-$15,000. The two main components of a standard residential seismic retrofit in San Jose are: (1) Foundation bolting — installing anchor bolts through the wood mudsill into the concrete foundation to prevent the house from sliding off its foundation; (2) Cripple wall bracing — adding plywood sheathing to the short “cripple walls” in the basement or crawl space that support the first floor, preventing them from collapsing in a lateral (side-to-side) earthquake motion. The California Earthquake Authority (CEA) offers Earthquake Brace+Bolt (EBB) grants of up to $3,000 to eligible San Jose homeowners to offset the cost.

Does My San Jose Home Need a Seismic Retrofit?

• Pre-1980 construction: Homes built before 1980 were not required to meet the seismic standards added to the California Building Code after the 1971 Sylmar earthquake and updated after the 1989 Loma Prieta earthquake (which had its epicenter in Santa Cruz, near San Jose)
• Raised foundation (crawl space): If your San Jose home has a crawl space (raised wood floor, not a concrete slab), it likely has cripple walls that would benefit from bracing
• No anchor bolts visible: Look in the crawl space at the mudsill (the bottom wood member sitting on the concrete foundation). If there are no bolts going through the mudsill into the concrete every 4-6 feet, your home is not adequately bolted
• Soft story (ground floor garage): Homes with a garage on the ground floor and living space above (common in 1960s-1980s San Jose construction) are at particularly high seismic risk — the soft story can collapse during an earthquake, as was widely seen in the 1994 Northridge earthquake
• Located near Hayward Fault: Parts of East San Jose, Fremont, Hayward, Berkeley, and Oakland sit near or on the Hayward Fault — the most likely source of the next major Bay Area earthquake (2% annual probability of M ≥ 6.7)

Quartz Construction performs residential seismic retrofits in San Jose including foundation bolting, cripple wall bracing, and soft-story strengthening. We help homeowners apply for Earthquake Brace+Bolt grants. CSLB #1003436 | Call (650) 749-7436.