FAQs

A. Seismic retrofitting of vulnerable homes is critical to reducing your risk of earthquake injury and damage.

The frames of older houses are often not bolted to their foundations, and their cripple wall may lack bracing. Houses without adequate bolting and bracing can slide or topple off their foundation during an earthquake.

These repairs can be completed with a proper seismic retrofit.

If you live in a retrofitted house or mobilehome, you're less likely to be injured during an earthquake, or displaced from your home.

A. Determining your risk from violent earthquake shaking goes beyond finding your location to the nearest fault. The United States Geological Survey (USGS) states three main factors that determine your seismic risk: the level of the seismic hazard, exposure to the hazard, and how vulnerable your community’s population and property is to the hazard.

Hazard: USGS Earthquake Hazard Maps are a great tool to depict hazard levels across the country. Interactive hazard maps are available from the California Governor's Office of Emergency Services (Cal OES) at the My Hazards Awareness Map website on the “Earthquake Risk” tab.

Exposure: Earthquake causalities are estimated and determined by the population in geographical areas with a higher risk of earthquakes such as the San Francisco Bay Area and Los Angeles basin. The quantity and quality of the infrastructure (roads, bridges, gas and power lines) in that area are also evaluated.

Vulnerability: The vulnerability of your home to seismic hazards is determined by whether it has earthquake-resistance construction.

A. Seismic retrofitting is the adjustment of existing structures to make them more resistant to earthquake activity, ground motion, or soil failure.

Consult the California Existing Building Code (CEBC) retrofit provisions. The code sets "minimum standards intended to improve the seismic performance of residential buildings; however, they will not necessarily prevent earthquake damage."

A. There are standard sets of plans made available to homeowners and contractors by local governments, to use as construction documents for the seismic retrofit of wood-frame, single-family dwellings. These plan sets include specifications, details, and instructions for installing foundation anchorage and cripple-wall bracing (for walls shorter than four feet). A registered design professional (architect or engineer) must design any modifications to plan-set provisions.

Visit our Resources page to download plan set PDFs.
 

A. Identifying your house’s age, construction and foundation type is the first step in the earthquake retrofit process. Almost any house built before 1980 can be improved to reduce earthquake risk. Even some houses built between 1980-1989 can be improved. Houses built in 1990 or after usually have earthquake resistant features installed during the original construction.

A visual inspection by a licensed contractor, engineer or architect can determine your home’s earthquake vulnerabilities. Recommendations from the licensed professional may suggest strengthening the connections between the house and the foundation, as well as strengthening the sub-area supporting walls.

Knowing what to do, where to do it, and how to do it are very important.
 

A: On average a project can last from 4 to 12 weeks, after receiving a client's permits and plans and depending on the scope of work, but construction work often takes only 1-3 days. In almost all cases, the work does not require entry to the inside of your home, which means now is a great time to get the ball rolling.

A: We recommend looking at our Resources page for information from partner organizations and to get started. You can also check out information and tips from these websites:

•  FEMA Foundation Systems
• Association of Bay Area Governments Earthquake Resilience Program
• EarthquakeSafety.com: Retrofitting
• California State Treasurer: CAL/CAP Seismic Safety Financing Program
• California Seismic Safety Commission: A Homeowner’s Guide to Earthquake Safety 2020
• City of San Jose: Earthquake Retrofit Your Home
• Earthquake Country: How to Hire Someone to Strengthen Your Home
• California State License Board: Ten Tips

A: There isn't a standard cost for earthquake retrofitting a home. The retrofitting repair range for a brace and bolt type of retrofit runs from $3,000 to $7,000. The Association of Bay Area Governments (ABAG) estimated the typical home retrofit that does not require an engineer costs about $4,500.

Larger homes, those built on hillsides, and those with basements or rooms over garages will typically cost more to retrofit. But many houses may require only bolting cost of about $3,000.

A: In 2014, when a moderate earthquake hit Napa, California, it cost individual homeowners as much as $300,000 to repair their homes. Most were older structures that were unable to stand up to the moderate magnitude 6.0 quake. Generally, the cost of earthquake repairs comes out of homeowner savings. In some cases, you may be able to report damages as deductible casualty loss on your tax return.

• The Earthquake Mitigation Incentive and Tax Parity Act was introduced in 2019 and would change the federal tax code. It would exempt from federal tax liability the funds from state programs that help homeowners protect their homes from earthquakes.
• Under California law (Revenue and Tax Code, Section 74.5), a homeowner can implement seismic-strengthening measures without a property tax reassessment. To receive the exclusion, you must have the work approved by the local building department and file a claim form with your county tax assessor.
• If you live in Berkeley or El Cerrito, the cities offer a transfer tax rebate if you retrofit your home within a year of buying it. You can also borrow money to make the repairs without paying any upfront costs. Homeowners or contractors must file a Seismic Retrofit Verification & Refund Application after the seismic work is completed.
• If you participate in an Earthquake Brace + Bolt grant program that is FEMA funded, that grant would not be taxable. 
• Check with your local city/county to find out if similar assistance is available in your area.

A: More than 1.2 million homes in California are in high-seismic-hazard areas and are vulnerable to earthquake shaking damage.

• The California Earthquake Authority (CEA) provides policyholder eligibility for the CEA Brace + Bolt program. This program offers grants of up to $3,000 to help for a seismic retrofit.
• The state Office of Emergency Services and CEA oversee the Earthquake Brace + Bolt program. ZIP Codes chosen for program participation are selected by the following criteria:
  • Earthquake Hazard: Hazard was identified using the United States Geological Survey (USGS) earthquake hazard map for California.
  • Earthquake Vulnerability: Vulnerability was represented by identifying the percentage of pre-1940 houses in ZIP Codes in California (US Census Data). Older houses are more likely to require earthquake bracing and bolting.
• Check out other local government seismic assistance programs listed through the California State Treasurer’s Office.
• Property Assessed Clean Energy (PACE) financing, offered in cities such as Berkeley, which allows property owners to borrow money to pay seismic retrofits and spread the cost of the upgrade over a period of time through a special assessment on their property tax bill.
• Low-income and fixed income residents of the San Francisco Bay Area may be eligible for grants specifically designated for home earthquake strengthening through the U.S. Department of Housing and Urban Development's block grant program. For more information, call (510) 577-6004. 
• City of Oakland: low income homeowners in the redevelopment zone may qualify for a grant for 50% of the cost of the work (up to $5,000) matched with a low interest loan for the remaining 50% of the cost. Retrofit permit fees for all residents are fixed at $250.
• For recently-purchased homes, there are transfer tax Rebates: The cities of Berkeley and El Cerrito offer rebates or refunds on a percentage of your home’s transfer tax if you complete a voluntary seismic retrofit of your residential property.

How your house is built, and its foundation type determine what type of retrofit your house needs. Houses with a raised concrete perimeter foundation that lack sill plate anchors and/or cripple wall bracing may follow existing state building code (CEBC, Chapter A3) or standard plan sets, which also provide step-by-step directions. Download plan sets on our Resources page [link to Resources].

The following types of houses may require an engineer to design a retrofit:

• Soft-story row houses
• Houses on hillsides
• Houses with living space over the garage
• Post and pier foundation houses

A. It means that the framing of the house’s first floor is composed of beams and cross-beams made of wood. You should be able to look under the house to see if wooden beams and cross-beams support the first floor.

A: A cripple wall, or what we call a crawl space wall, is a less-than-full-height wall, typically four feet or less tall, located between the house’s foundation and the base of the house’s first floor.

A: Your home’s foundation must support not only the building above it but transfer loads acting on the structure to the supporting soils.

A continuous perimeter foundation is concrete and runs without gaps under the exterior walls of your home. California Existing Building Code, Chapter A3, and standardized plan sets are designed specifically for this type of foundation that lacks sill plate anchors and/or cripple wall bracing.

If you have a partial perimeter foundation or if your house foundation is made from unreinforced masonry or stone, you’ll need to have your house evaluated by an engineer or design professional before planning or starting a retrofit, to ensure you will meet building-code requirements.

A slab-on-grade-foundation house has no basement or crawl space and therefore no basement wall. Your house is built on a solid slab of concrete.

A low-slope building site has a natural slope of 10% or less. If columns or beams support a house, it’s likely the house has been built on a slope greater than 10%.

A. It is common and accepted practice for seismic improvements to be planned by a licensed contractor, civil or structural engineer, or architect.

Many cities now have “prescriptive or standard plans,” which an experienced, licensed contractor or homeowner-builder can use in planning the retrofit. Engineered plans are advisable or may be required in the following situations:

• Large, complex, multilevel houses.
• Stilt houses on steep hillsides.
• Houses with large openings in lower level walls.
• Houses with serious foundation and/or drainage problems.

A. You may follow personal recommendations from friends and family, or consider online directories or paid advertisements. Search for licensed contractors in the Contractor Directory on the Earthquake Brace + Bolt (EBB) website. Contractors on the EBB list have completed FEMA training for retrofits of houses with raised continuous perimeter foundations and cripple walls.

Before you make your final decision and sign a contract, the California Seismic Commission and the Contractor’s State License Board (CSLB) recommends:

• Getting at least three written bids on the project.
• Checking at least three customer references.
• Verifying the contractor's business location and telephone number.
• Ensuring the contractor has a license and the legally required bond.
• Verifying the contractor's workers’ compensation and commercial general liability insurance coverage.

A. The California State Contractors State License Board (CSLB), part of the state Department of Consumer affairs, provides online search information about contractors. You can search for a licensed contractor, verify contractor license number, the contractor’s business name, and confirm that the license is active.

A. The California Seismic Safety Commission recommends that contractors be paid in installments as the work is completed. Other tips from the Commission include:

• Keep the down payment low. By law, a down payment on a home improvement contract cannot exceed 10% of the contract price or $1,000, whichever is less.
• Wait to pay the final bill until the local building department has signed off on the work and you have conducted a final review of the work to make sure it is complete and correct.

You can also check the California State Contractors State License Board (CSLB) for your contractor’s information and to verify they are licensed.

A. Knowing what to do, where to do it, and how to do it are important. A good plan is the place to begin. Often DIY homeowners choose to undertake some of the preparation and follow-up work themselves to save some money.

The details of solving tricky situations under a house are not covered in most do-it-yourself manuals. Making sure certain details are handled properly often makes a big difference in the strength of the retrofit. Prior to the installation of a retrofit, a good plan is needed. Prescriptive Plan Sets are available for certain types of houses.

For a raised foundation property, a seismic retrofit involves bolting or bolting and bracing the house to its foundation in compliance with California Existing Building Code Chapter A3. Remember, most foundation repairs require a building permit and plans to start work.

• City of San Leandro has an earthquake strengthening program with valuable DIY handbooks and tools.
• Association of Bay Area Governments (ABAG) standard plan for retrofits is available for San Francisco Bay Area residents.
• The City and County of Los Angeles and many of its surrounding cities accept the LA Standard Plan Set #1. Download them on our Resources page.

Other types of retrofits, such as post and pier or living space over garage, require an engineered retrofit and may be too complicated for a do-it-yourselfer to completed.

A. Because requirements vary, check with your local building inspection department to verify the construction documents and drawings required for a building permit. Many building departments accept standard plan sets, which the homeowner-builder or contractor can access online. If you hire a registered design professional (architect or engineer) to design a retrofit for your cripple wall house, specify that they design the retrofit in accordance with Chapter A3 of the CEBC or one of the plan sets adopted by your local building official. Download plan sets on our Resources page.
 

A. There are standard sets of plans made available to homeowners and contractors by local governments, to use as construction documents for the seismic retrofit of wood-frame, single-family dwellings. These plan sets include specifications, details, and instructions for installing foundation anchorage and cripple-wall bracing (for walls shorter than four feet). A registered design professional (architect or engineer) must design any modifications to plan-set provisions.

Visit our Resources page to download plan set PDFs.
 

A. Check with your local building inspection department to see if it has adopted a standard plan set that meets the requirements of the CEBC, Chapter A3.

A number of jurisdictions have accepted either “Plan Set A” or LA Standard Plan #1. These plan sets apply to any wood-framed, single-family dwelling with a raised foundation and with or without a cripple wall of less than four feet.
 
Download plan sets on our Resources page.