Earthquake retrofits for Palo Alto homes

Most Palo Alto houses are wood frame. Wood bends rather than breaks in an earthquake. The weak point is usually not the walls but the connection between the house and its foundation, or a ground floor that is mostly garage door. A retrofit targets those weak links. Done well, it is one of the most cost-effective upgrades an owner of an older house can make. For a buyer, knowing whether the work has been done changes how you read an inspection report and an insurance quote.

This page explains the common retrofits, the state grant programs as their operators published them in 2025 and 2026 and what Palo Alto requires. It is general information, not engineering, legal or insurance advice. Hire a licensed engineer or contractor for your own house and confirm program rules with the official sources. For what to do during and after shaking, see our earthquake safety guide.

Why older houses are vulnerable

The San Andreas Fault runs a few miles west of town and the Hayward Fault sits across the bay. Palo Alto has felt both kinds of damage. Our pages on the 1906 earthquake and the 1989 Loma Prieta earthquake tell those stories. Soil matters too. The Palo Alto annex to the county hazard plan rates liquefaction potential as moderate to high from the center of the city toward the bay.

Three house types worry engineers most:

• Unbolted houses. Many houses built before modern codes simply rest on the foundation. In strong shaking the frame can slide off.
• Cripple wall houses. A cripple wall is a short wood wall between the foundation and the first floor, enclosing the crawl space. If it is not braced, it can fold over and drop the house.
• Soft-story buildings. A ground floor with large openings, often a garage under living space, lacks the walls needed to resist sideways force.

Slab houses, including most Eichlers, have no crawl space or cripple wall, so foundation bolting is usually not the issue. Our Eichler buying guide covers the questions that do apply to them.

What a brace-and-bolt retrofit involves

For a typical raised-foundation house, the work happens in the crawl space and takes days, not months.

1. Bolting. The contractor drills through the wood sill plate into the concrete foundation and installs anchor bolts or retrofit plates at set spacing.
2. Bracing. Plywood or similar structural panels are nailed to the inside of the cripple walls in a set pattern, turning them into shear walls.
3. Connections. Framing connectors tie the floor framing to the sill and the braced walls.
4. Water heater. The water heater is strapped, which the state grant program requires as part of the job.

California has a prescriptive standard for this work, Chapter A3 of the California Existing Building Code. Approved standard plan sets are based on it. For cripple walls of 4 feet or less, a contractor can often work from the standard plans. Taller cripple walls, hillside lots and unusual foundations usually call for an engineer. A crumbling or unreinforced foundation is a bigger job that bolting alone will not fix.

State grant programs: status for 2026

The California Residential Mitigation Program, a joint effort of the California Earthquake Authority and the state's emergency services office, runs the main homeowner grants. Here is what we found as of November 1, 2026.

The city's 2025 announcement listed the main EBB rules for that round. Houses had to be built before 1980. The participant had to be the legal owner. Only one registration was allowed per household. Non-owner-occupied homes were eligible for up to five properties. The permit had to be dated after acceptance into the program. Contractors had to come from the program's directory. Bids over $10,000 required a second bid. Owner-builders could not be reimbursed for labor. Houses already retrofitted were not eligible.

The EBB program page says registration opens for a limited time each year and offers a sign-up for notice when it reopens. It also describes supplemental grants for income-eligible households, with an income limit of $94,480, paid first come, first served while funds last. Rules can change from one round to the next, so read the current terms before you hire anyone.

Soft-story houses and apartments

Houses with rooms over the garage

A split-level or two-story house with a bedroom over a wide garage door can behave like a small soft-story building. The fix is usually new plywood shear walls, steel frames or both around the garage opening, designed by an engineer. That is why the ESS grant has been larger than the EBB grant.

Apartment buildings

Palo Alto was early to study seismic risk. In 1986 the City Council adopted the Seismic Hazards Identification Program, Chapter 16.42 of the municipal code. A 2017 city staff report said it required evaluations of unreinforced masonry buildings and some large older buildings, identified 89 buildings and saw about 66 strengthened, demolished or proposed for demolition. The same 2017 work counted 294 wood-frame soft-story buildings and 37 concrete ones built before 1977 and proposed a mix of voluntary and mandatory steps.

We could not confirm that a mandatory soft-story retrofit ordinance has been adopted since. The state's 2026 EMR grant named 14 cities with mandatory soft-story programs, including San Jose, Oakland, Berkeley and San Francisco. Palo Alto was not on that list. If you rent or are buying in an older apartment or condo building with parking under units, ask the owner or association whether it has been evaluated or retrofitted. Our renting guide lists other questions for landlords.

Permits and city rules

Seismic retrofit work generally needs a building permit in Palo Alto. Applications go through the city's online permit portal. Inspections confirm the bolts, panels and nailing before they are covered. Our building permits guide covers the Development Center and the inspection schedule.

A few city layers can affect a retrofit:

• Historic houses. Buildings on the Palo Alto Historic Inventory can use the California Historical Building Code, which allows engineered alternatives that keep original fabric. Work hidden in a crawl space rarely raises design questions. See historic home rules.
• Grant timing. If you want a state grant, do not pull your permit early. EBB has required a permit dated after acceptance.
• Bigger remodels. A major remodel can trigger structural upgrades under the building code. Ask your designer early.

For buyers: reports, taxes and insurance

When you tour an older raised-foundation house, ask the seller for any retrofit permit, engineer's letter or grant completion paperwork. A general inspector or foundation contractor can tell you whether anchor bolts and braced cripple walls are visible. Our home inspections guide explains which specialist to call.

Two money questions follow.

• Insurance. The California Earthquake Authority offers a premium discount of up to 25 percent for a verified retrofit of a qualifying older house. Our home insurance guide explains how earthquake policies work.
• Property tax. California law excludes qualifying seismic retrofit improvements from reassessment, but the owner has to file a claim. Ask the Santa Clara County Assessor about the form and deadline before the work is finished.

Frequently asked questions