How to Prepare for the Next Major Bay Area Earthquake: The Complete Homeowner’s Guide
San Francisco Bay Area
September 26, 2026
No one can predict the exact date, time, or location of the next major Bay Area earthquake. But homeowners can prepare now.
Earthquake preparedness has two separate parts:
- Preparing your household, belongings, utilities, and emergency supplies.
- Preparing the house itself to resist shaking and remain usable afterward.
The U.S. Geological Survey’s published Bay Area forecast estimated a 72% probability of at least one magnitude 6.7 or larger earthquake somewhere in the San Francisco Bay region during the 2014–2043 forecast period. That is not a prediction of when the earthquake will happen. It is a reason to treat preparation as a practical responsibility instead of a future problem. (usgs.gov)
Bay Area Earthquake Preparedness Checklist
Start here:
- Download the MyShake app and enable emergency alerts.
- Learn and practice Drop, Cover, and Hold On.
- Create a family communication and meeting plan.
- Store water, food, medications, flashlights, batteries, and first-aid supplies.
- Secure bookcases, televisions, mirrors, cabinets, appliances, and water heaters.
- Learn how to shut off gas, water, and electricity safely.
- Review earthquake insurance and important financial documents.
- Identify your home’s foundation type and structural vulnerabilities.
- Check whether the house is anchored to its foundation.
- Check for cripple walls, soft-story conditions, or large garage openings.
- Evaluate foundation deterioration, settlement, drainage, and crawl-space moisture.
- Determine whether previous retrofit work was actually completed correctly.
- Create a plan for inspecting the property after a major earthquake.
California’s Earthquake Warning system can provide seconds of warning in some situations, but warnings are not predictions and may arrive after an earthquake has already started. California recommends MyShake, Android Earthquake Alerts, and Wireless Emergency Alerts as available warning methods. (earthquake.ca.gov)
How Likely Is Another Major Bay Area Earthquake?
The Bay Area contains multiple active fault systems, including the Hayward-Rodgers Creek, San Andreas, Calaveras, and San Gregorio fault systems.
Risk varies by:
- Distance from the fault;
- Local soil conditions;
- Bay fill or soft soils;
- Liquefaction potential;
- Hillside location;
- Building age;
- Foundation type;
- Structural configuration; and
- The condition of previous repairs.
Two homes on the same block can respond differently to the same earthquake. One may be well anchored and properly braced. Another may have deteriorated foundations, weak cripple walls, inadequate connections, or a soft-story condition.
The right question is not:
“Is my house near a fault?”
The better question is:
How will this particular home transfer earthquake forces from the roof and upper floors into the soil?
Prepare Your Family Before the Earthquake
A structural retrofit cannot replace household preparation.
Create a plan that addresses:
- Where family members will meet;
- How you will communicate if phone service is limited;
- Who will care for children;
- Who will care for pets;
- How medications will be replaced;
- How elderly or disabled family members will be assisted;
- Which out-of-area contact everyone should use;
- Where emergency documents will be stored; and
- What each person should do if separated.
Practice the plan. Earthquake Country Alliance recommends planning, practicing Drop, Cover, and Hold On, identifying safe locations, preparing supplies, and sharing the plan with people who care for your home, children, or pets. (earthquakecountry.org)
Build an Earthquake Emergency Kit
A basic earthquake kit should include:
- Drinking water;
- Shelf-stable food;
- Prescription medications;
- First-aid supplies;
- Flashlights;
- Extra batteries;
- Battery or hand-crank radio;
- Phone chargers or power banks;
- Cash;
- Work gloves;
- Sturdy shoes;
- Dust masks;
- Basic tools;
- Sanitation supplies;
- Pet food and pet supplies;
- Blankets;
- Copies of important documents; and
- Emergency contact information.
Keep supplies where they can be reached after shaking. Do not store the only flashlight or shoes inside a garage that may be difficult to open.
Secure the Things Inside Your Home
Many earthquake injuries come from falling or moving contents rather than complete building collapse.
Secure:
- Bookcases;
- Dressers;
- Televisions;
- Mirrors;
- Artwork;
- Kitchen cabinets;
- Water heaters;
- Refrigerators;
- Garage shelving;
- Heavy objects above beds;
- Appliances; and
- Items stored on high shelves.
Use appropriate straps, brackets, latches, anchors, and restraint systems. A heavy television that is not secured can become a serious hazard even if the house itself remains standing.
During an Earthquake: Drop, Cover, and Hold On
If shaking begins:
- Drop to the ground;
- Cover your head and neck;
- Get under a sturdy table or desk if possible;
- Hold on until the shaking stops;
- Stay away from windows and glass;
- Do not run outside while the building is shaking;
- Do not stand in a doorway unless specifically instructed for a particular circumstance; and
- Expect aftershocks.
If you are outside, move away from buildings, walls, trees, utility lines, and other falling hazards.
If you are driving, pull over when safe and remain in the vehicle until the shaking stops.
Official California guidance emphasizes Drop, Cover, and Hold On rather than running outside or standing in doorways. (earthquake.ca.gov)
The House Itself: Will It Stay Connected to the Foundation?
Emergency supplies help your family survive the disruption. They do not strengthen the house.
Structural earthquake preparation may involve:
- Foundation anchorage;
- Mudsill connections;
- Cripple-wall bracing;
- Shear walls;
- Hold-downs;
- Floor-to-wall connections;
- Posts and piers;
- Beam connections;
- Soft-story reinforcement;
- Foundation repair; and
- A continuous load path.
A continuous load path is the structural chain that transfers earthquake forces from the roof and upper floors through the walls, framing, foundation, and into the soil.
A retrofit is not simply “adding bolts.” Bolts are only one component of a larger system.
For a broader overview, read:
Your Home vs. the Next Earthquake: A Practical Guide for Bay Area Owners
Under Your Home: The Bay Area Crawl-Space and Foundation Guide
Beyond Foundation Bolts: The California Seismic Load Path Guide
Does My Bay Area Home Need an Earthquake Retrofit?
No single factor determines whether a home needs a retrofit. However, an evaluation is especially appropriate for homes with:
- Older raised foundations;
- Crawl spaces;
- Unbraced cripple walls;
- Inadequate foundation anchorage;
- Deteriorated concrete foundations;
- Living space over a garage;
- Large ground-floor openings;
- Hillside construction;
- Previous additions;
- Irregular framing;
- Questionable prior retrofit work; or
- Little documentation of what was previously installed.
Homes built before modern seismic requirements may have vulnerabilities that are not visible from the living area. The age of the home is a screening factor, not a final diagnosis.
Read:
Does My Home Need an Earthquake Retrofit? A Bay Area Homeowner’s Guide
What Does an Earthquake Retrofit Actually Do?
Foundation Bolting
Foundation bolting connects the wood sill plate to the concrete foundation. This helps reduce the risk of the house sliding relative to the foundation during shaking.
The correct hardware, spacing, embedment, edge distance, concrete condition, and installation method matter. A bolt installed in deteriorated concrete may not provide the intended result.
Cripple-Wall Bracing
Cripple walls are short walls between the foundation and the first floor. If they are not properly braced, they can rack, buckle, or collapse during lateral movement.
Bracing may include:
- Structural plywood;
- Proper nailing;
- Blocking;
- Framing reinforcement;
- Hold-downs; and
- Connections to the foundation and floor framing.
Shear Walls and Load-Path Connections
Shear walls resist side-to-side forces. Their effectiveness depends on more than plywood alone.
The system may require:
- Proper framing;
- Edge nailing;
- Blocking;
- Foundation anchorage;
- Hold-downs;
- Transfer connections; and
- Continuity into the floor and roof systems.
Posts, Piers, and Beams
Interior posts, piers, and beams are not automatically included in every minimum retrofit. Their importance depends on how they support the floor system and participate in the overall load path.
They may require evaluation where they:
- Support major framing;
- Have inadequate connections;
- Show deterioration;
- Contribute to floor movement;
- Transfer forces between levels; or
- Affect the performance of the retrofit system.
Soft-Story Reinforcement
Soft-story conditions occur when one level has significantly less lateral strength or stiffness than the levels above it.
Common examples include:
- Living space over a large garage;
- Open parking levels;
- Large garage-door openings;
- Open commercial storefronts; and
- Apartment buildings with tuck-under parking.
Possible retrofit systems include:
- Shear walls;
- Steel moment frames;
- Collectors;
- Hold-downs;
- New foundations; and
- Engineered connections.
Read:
Seismic Retrofitting and Structural Reinforcement in the Bay Area
Crawl-Space Homes Have Specific Vulnerabilities
A typical raised-foundation home transfers forces through a sequence:
Roof and upper floors → walls and cripple walls → floor framing → mudsill and foundation → soil
A weakness anywhere in that chain can affect performance.
Under the home, an evaluation may examine:
- Foundation walls;
- Mudsills;
- Anchor bolts;
- Cripple walls;
- Posts;
- Piers;
- Beams;
- Floor joists;
- Rollover blocks;
- Shear connections;
- Existing retrofit hardware;
- Moisture;
- Rot;
- Corrosion; and
- Crawl-space access.
A short access estimate may identify one visible issue while missing the relationship between several components.
That is why crawl-space evaluation should be based on actual access, photographs, measurements, and documented findings rather than a quick look from the entry opening.
Living Over a Garage? Check for Soft-Story Conditions
Homes with living space above a garage deserve specific attention because the large opening may reduce the strength and stiffness of the lower level.
Warning signs include:
- A wide garage opening;
- Few or narrow wall segments;
- Large windows or doors at the ground level;
- A floor above that appears to move independently;
- Cracks near garage corners;
- Weak or deteriorated posts;
- Inadequate foundation support; and
- Previous work that was not engineered or documented.
Not every living-over-garage home has a soft-story problem. The condition depends on the entire structural system.
Foundation Condition Comes Before or Alongside Retrofit Work
A seismic retrofit attaches to the existing structure. If the foundation or framing is deteriorated, the attachment point may be the weak link.
Before installing retrofit hardware, check for:
- Crumbling concrete;
- Spalling;
- Efflorescence;
- Major cracking;
- Foundation displacement;
- Deteriorated foundation caps;
- Rot or decay;
- Damaged mudsills;
- Corroded hardware;
- Settlement;
- Soil movement; and
- Water exposure.
A retrofit should not be designed in isolation from the foundation it depends on.
Read:
What Should I Consider When Planning Earthquake Retrofits for My Bay Area Home?
How Soil Affects Foundation Stability When Repairs Are Required
Drainage, Soil, and Earthquake Performance
Drainage problems are not automatically seismic problems. But long-term moisture and soil movement can affect the condition of the structure before an earthquake occurs.
Relevant conditions include:
- Expansive clay soil;
- Erosion;
- Poor grading;
- Standing water;
- Crawl-space moisture;
- Foundation saturation;
- Settlement;
- Differential settlement;
- Corrosion;
- Wood decay; and
- Retaining-wall movement.
A home with a deteriorated or moving foundation may begin an earthquake with less structural capacity than a home with stable, dry, properly supported conditions.
Related resources:
Why Is There Standing Water Under My House?
Why Does My Crawl Space Smell Musty?
Clay Soil and Seasonal House Movement in the Bay Area
My House Was Already Retrofitted. Am I Done?
Not necessarily.
A previous retrofit should be evaluated based on:
- What standard or plan was used;
- Whether permits and plans exist;
- What was actually installed;
- Whether the installation matches the plans;
- Whether required connections are present;
- Whether hardware is correctly installed;
- Whether the foundation remains sound;
- Whether additions changed the load path; and
- Whether moisture or deterioration affected the work.
A permit, inspection sign-off, grant approval, or photograph package may document part of the project. It does not automatically prove that every concealed condition was correctly installed.
Read:
Seismic Truth Audit™: Existing Retrofit Reality Check
Does Your Existing Seismic Retrofit Pass a Seismic Truth Audit?
The Real Cost of a Cheap Seismic Retrofit
Plan Set A, FEMA P-1100, and Custom Retrofits
Homeowners often hear several retrofit terms used as though they mean the same thing.
They do not.
Plan Set A
Plan Set A is a prescriptive retrofit approach used for certain eligible residential conditions. It generally represents a minimum defined scope, not a guarantee that the home will experience no damage.
FEMA P-1100
FEMA P-1100 provides prescriptive retrofit guidance for certain existing wood-frame homes and addresses more conditions than a basic bolting-only approach.
Custom-Engineered Retrofit
A custom-engineered retrofit may be appropriate when the home has:
- Unusual framing;
- Significant additions;
- Soft-story conditions;
- Complex foundations;
- Hillside construction;
- Commercial or multifamily use;
- Major irregularities; or
- Conditions outside prescriptive programs.
Performance-Based Retrofit
Performance-based approaches evaluate expected building performance rather than only applying a minimum prescriptive checklist. FEMA P-58 is an example of a broader performance-based methodology.
Read:
What Is the FEMA P-58 Seismic Methodology?
The right question is not whether one plan is universally “the best.” The right question is:
What protection level is appropriate for this structure, this foundation, this budget, and this owner’s risk tolerance?
How Much Does a Bay Area Earthquake Retrofit Cost?
There is no single price because the scope depends on:
- House size;
- Foundation type;
- Crawl-space access;
- Cripple-wall height;
- Concrete condition;
- Existing hardware;
- Number and location of connections;
- Soft-story conditions;
- Hillside conditions;
- Required foundation repairs;
- Engineering;
- Permits;
- Finish restoration; and
- Desired protection level.
A basic retrofit may cost far less than a whole-home system involving foundation replacement, drainage, soft-story strengthening, or custom engineering.
Read:
How Much Does a Seismic Retrofit Cost in the San Francisco Bay Area?
What Makes Seismic Retrofit Costs Increase?
Do not compare prices without comparing scope. One contractor may be pricing foundation bolting only. Another may include cripple-wall bracing, crawl-space framing, hold-downs, drainage, permits, photographs, and finish restoration.
Earthquake Brace + Bolt and Other Programs
Earthquake Brace + Bolt, commonly called EBB, is a grant-based program for certain eligible homes and retrofit scopes. Program requirements, contractor requirements, funding, deadlines, and eligibility can change.
Homeowners should verify current requirements through the official program before relying on an article or contractor statement.
A grant can help reduce the cost of a minimum eligible retrofit. It does not necessarily fund every repair the home needs.
Read:
EBB Retrofit Preparation Guide
Does EBB Vet and Regulate Contractors? Here’s the Truth
Should You Buy Earthquake Insurance?
Earthquake insurance and structural mitigation solve different problems.
Insurance may help address covered losses after an earthquake, subject to:
- Deductibles;
- Coverage limits;
- Exclusions;
- Dwelling coverage;
- Personal-property coverage;
- Loss-of-use coverage; and
- Policy terms.
A retrofit may reduce damage exposure but does not replace insurance.
Homeowners should compare the cost of coverage with the deductible and the potential financial consequences of remaining uninsured. For policy-specific advice, speak with the California Earthquake Authority, your insurer, or a qualified insurance professional.
Read:
CEA Earthquake Insurance Evaluation and Retrofit Verification
Earthquake Preparation by House Type
Older Raised-Foundation Home
Primary concerns may include:
- Foundation anchorage;
- Cripple-wall bracing;
- Mudsill condition;
- Posts and piers;
- Crawl-space access;
- Foundation deterioration; and
- Moisture.
Living-Over-Garage Home
Primary concerns may include:
- Large openings;
- Weak garage-level walls;
- Soft-story behavior;
- Transfer connections;
- Foundation capacity; and
- Engineering requirements.
Hillside Home
Primary concerns may include:
- Complex load paths;
- Retaining walls;
- Slope movement;
- Foundation steps;
- Soil movement;
- Drainage; and
- Access for construction.
Slab-on-Grade Home
The evaluation may focus more on:
- Foundation cracking;
- Shear walls;
- Wall anchorage;
- Roof and wall connections;
- Additions; and
- Irregular framing.
Crawl-space and cripple-wall recommendations may not apply.
Home With an Existing Retrofit
Primary questions include:
- What was installed?
- Was the work permitted?
- Does it match the plans?
- Are connections missing?
- Has the foundation deteriorated?
- Did later remodeling change the structural system?
What to Do After a Major Earthquake
After significant shaking:
- Check for injuries;
- Check for fire or smoke;
- Leave if there is a gas smell;
- Avoid damaged electrical systems;
- Watch for falling objects;
- Expect aftershocks;
- Check for water leaks;
- Look for major new cracks;
- Look for foundation displacement;
- Check chimneys, stairs, decks, and retaining walls; and
- Do not enter an unsafe crawl space.
Call qualified professionals or emergency officials when conditions are beyond a basic homeowner observation.
Do not crawl underneath a visibly shifted, leaning, collapsed, or unstable structure.
How to Check Your House After an Earthquake
Exterior
Look for:
- New foundation cracks;
- Separation between the house and foundation;
- Leaning walls;
- Damaged chimneys;
- Porch or deck separation;
- Shifted stairs;
- Broken utility connections;
- Retaining-wall movement; and
- New drainage or soil failures.
Interior
Look for:
- New diagonal wall cracks;
- Doors and windows that suddenly bind;
- Sloping or uneven floors;
- Ceiling separation;
- Cabinet movement;
- Broken tiles; and
- New gaps around trim.
Crawl Space
Do not enter if there is:
- Structural instability;
- Gas odor;
- Electrical damage;
- Standing contaminated water;
- Fallen framing;
- Severe foundation movement; or
- Another obvious hazard.
Ten Questions to Ask About Your Home
- How old is the home?
- What type of foundation does it have?
- Is the house anchored to the foundation?
- Does it have cripple walls?
- Are the cripple walls braced?
- Is there living space above a garage?
- Is the foundation deteriorated or moving?
- Are there drainage or crawl-space moisture problems?
- Has the home been retrofitted before?
- Do you have plans, permits, photographs, or documentation showing what was installed?
If you cannot answer several of these questions, that does not prove the home is unsafe. It does indicate that you may be making a major decision without sufficient information.
How to Prepare This Week
Today
- Download MyShake;
- Confirm emergency contacts;
- Identify safe locations in each room; and
- Move heavy objects away from beds and seating areas.
This Weekend
- Secure furniture and televisions;
- Check the water heater;
- Gather emergency supplies;
- Identify utility shutoffs; and
- Make a family communication plan.
This Month
- Review insurance;
- Gather permits and prior retrofit documents;
- Identify your foundation type;
- Check the crawl space if safe and accessible;
- Look for moisture and deterioration; and
- Evaluate whether the home has a raised foundation, cripple walls, soft-story condition, or complex addition.
Before the Next Major Earthquake
- Have significant structural concerns evaluated;
- Compare retrofit scopes rather than only prices;
- Repair foundation or drainage conditions that affect the structure;
- Decide whether minimum, enhanced, or custom protection is appropriate; and
- Document the work after completion.
Frequently Asked Questions
When will the next major Bay Area earthquake happen?
No one can predict the exact date, time, or location of the next major earthquake. Probability forecasts explain regional risk but do not provide a schedule.
What are the chances of a major Bay Area earthquake?
The USGS published forecast for the San Francisco Bay region estimated a 72% probability of at least one magnitude 6.7 or larger earthquake during the 2014–2043 forecast period. (usgs.gov)
Does my Bay Area house need an earthquake retrofit?
It depends on the home’s age, foundation type, framing, anchorage, cripple walls, soft-story conditions, additions, soil, foundation condition, and existing work. A site-specific evaluation is necessary to determine the appropriate scope.
What year homes need earthquake retrofitting?
There is no single construction year that automatically determines the answer. Older homes may have more vulnerabilities, but newer or remodeled homes can also contain structural, foundation, or connection problems.
How do I know if my house is bolted to the foundation?
A crawl-space inspection may reveal anchor bolts, epoxy-set anchors, washers, nuts, mudsills, and related hardware. Some conditions remain concealed and may require further investigation.
What is a cripple wall?
A cripple wall is a short framed wall between the foundation and the first floor. Unbraced cripple walls can rack or collapse during earthquake shaking.
What is a soft-story house?
A soft-story house has a lower level with substantially less strength or stiffness than the levels above it. Large garage openings and open lower floors are common examples.
Does earthquake retrofitting prevent all damage?
No. Retrofitting is intended to improve structural performance and reduce risk. It does not guarantee that a building will suffer no damage or remain fully usable after every earthquake.
Is Earthquake Brace + Bolt worth applying for?
A grant can reduce the cost of an eligible minimum retrofit. Homeowners should still understand what the funded scope does and does not address, including foundation, drainage, framing, and additional vulnerabilities.
Can I retrofit a house that already has foundation problems?
Possibly, but foundation deterioration, movement, moisture, or settlement may need to be addressed before or together with seismic work.
How do I know whether an old retrofit was done correctly?
Compare the installed work with the plans, permits, photographs, applicable requirements, hardware specifications, and visible construction conditions. A previous permit or grant approval does not automatically establish that every concealed component was correctly installed.
Should I enter my crawl space after an earthquake?
Not if there is structural instability, gas odor, electrical damage, standing contaminated water, collapsed framing, or another obvious hazard. Wait for qualified assistance.
Final Takeaway
Preparing for the next major Bay Area earthquake requires more than buying an emergency kit.
Household preparation helps people survive the event. Structural preparation helps the building resist shaking and recover afterward.
Start with the basics:
- Prepare your household;
- Secure your contents;
- Learn Drop, Cover, and Hold On;
- Download earthquake alerts;
- Identify your foundation type;
- Check for cripple walls and soft-story conditions;
- Review drainage and foundation conditions;
- Verify previous retrofit work; and
- Compare retrofit scopes based on documented conditions, not just price.
If you want to understand how your particular home is likely to perform, the next step is a site-specific evaluation rather than a generic internet answer.
Schedule a Seismic Safety Visit
This article provides general earthquake-preparedness and construction information. It is not a structural-engineering report, geotechnical report, legal advice, insurance advice, or guarantee of future building performance.
