The shakes over the last few days got the phone ringing in our office about residential earthquake safety strategies, renovations, and seismic retrofitting.
If you live in the San Francisco Bay Area, earthquakes are a fact of life. It’s the elephant in the room that most don’t want to discuss, but with your family’s well-being on the line, we’ve got to make sure that elephant doesn’t turn into a bull in a china shop.
Some of you might even be aware that there’s a 2027 deadline (June 9th, more specifically) for concrete building owners to submit proof of safety compliance (you’ll need an architect to do this) or be at the mercy of mandated actions and potential fines or penalties.
Code compliance aside, this article will review how you, as the homeowner, can implement earthquake safety into your life while understanding the role and importance of seismic retrofitting.
Who is at Risk?
While most building can easily withstand their own static weight against gravity with no risk of failure, the types of load introduced by an earthquake are dynamic and lateral. In other words, side-to-side shaking forces.
Most new structures are ok, because they already meet these lateral forces. Older ones? Maybe, maybe not. After 1933, some laws and codes were established, but they were less rigorous than today’s standards, and they don’t account for unpermitted modifications that may have been made. To truly assess seismic strength/weakness requires a structural analysis. But there are some give-aways: brick foundations, and soft stories are red flags. A “soft story” results from walls that are mostly covered in openings, like garage doors and entrances without much wall – we saw al lot of these collapse in the Marina.
What is Seismic Retrofitting?
Let’s start at square one. Seismic retrofitting is the process of adding lateral strength to your home so that it can better withstand earthquake forces: typically by strengthening your home’s connection to its foundation and reinforcing structural weak points.
In practical terms, structural retrofitting usually involves two main actions:
Sheer walls – Adding plywood sheathing or engineered panels to vulnerable walls to keep the house from toppling sideways like a house of cards during seismic activity.
Bolting/Hold-downs – Connecting all of the walls, beams, floors, roof and foundation together using bolts and connection hardware to keep the home from sliding apart.
Leveling – In San Francisco, we often see homes that have differential settlement, the floors are sloping because the foundation is sinking in places. This is not usually a seismic issue per se, but it often comes up and is addressed in conjunction with seismic retrofits. Doing jacking/leveling in conjunction with foundation bolting can make sense in many cases.
The work often happens in the ground floor/garage, around the perimeter of your foundation and in other vulnerable areas like the facade. But upper levels can be vulnerable as well, particularly where there are large window walls or large open spaces without some uninterrupted wall space
When is it required
San Francisco requires mandatory seismic retrofits for older, wood-framed, multi-unit buildings with a “soft-story” ground floor. But for single family homes, it is usually voluntary, unless you are doing a renovation that triggers upgrade. Some types of alterations that will trigger a seismic upgrade requirement include:
- Adding a story (vertical addition)
- A horizontal addition increasing the building footprint by a certain amount
- Converting non-habitable ground level area to living space
- Removing more than a third of the center wall that goes the long direction of the house on any level
If you plan to embark on any of this work, it is wise to make sure you are working with a design professional who understands the code implications.
How Much Does Seismic Retrofitting Cost?
Outside of what retrofitting actually entails, the next question is almost always about costs. The good news is that seismic retrofitting costs in San Francisco can be surprisingly affordable for most homes (there’s a subsidy, too) – but certain structures or locations can complicate the issue.
Here’s how costs generally break down:
Basic Bolting & Bracing: $3,000 – $8,000 for simpler homes where you’re preventing the house from separating at the foundation.
Foundation Anchoring with Shear Ties: $6,000 – $12,000 when you need more comprehensive perimeter reinforcement.
Comprehensive Retrofits: $15,000 – $25,000+ when foundation work, replacement, or structural repairs are involved.
Hillside Homes: Can exceed $50,000 due to complex foundation conditions and access challenges. Considering the substantial amount of work that has to be done at this budget, many San Francisco home owners choose to go all-in on a whole-home remodel.
The Good News: Financial Assistance Exists
California’s Earthquake Brace + Bolt (EBB) program offers grants up to $3,000 for eligible homeowners in high-risk ZIP codes. This state-sponsored incentive program was developed specifically to help offset seismic retrofit costs for older homes whose foundations don’t meet current building standards.
If your home qualifies (concrete or reinforced masonry foundation, cripple walls or stem walls, located in a program ZIP code) that $3,000 subsidy can cover a significant portion of basic retrofitting work.
The program requires proof that your water heater is properly strapped. During past earthquakes, unanchored water heaters have moved or tipped over, causing gas line leaks, water damage, and electrical hazards. It’s a small requirement that addresses a common source of post-earthquake damage.
Where to start
Basic voluntary retrofits like foundation bolting can be usually be handled by a qualified contractor. But more complicated retrofits will benefit from, or require an analysis and design by a structural engineer. You can work with your contractor on this, or you could start with an engineer, or architect if you are doing a renovation.
Can I Buy an Earthquake-Damaged Home?
In short, yes, but with your eyes wide open.
Sellers are required to disclose any known defects, but if they inherited issues that were never disclosed to them, those problems will pass undisclosed to you. This is where due diligence becomes critical.
Make seismic inspections part of your pre-purchase planning. Have a structural engineer assess the foundation, framing connections, and any previous earthquake damage or repairs. The inspection report gives you leverage to negotiate for seismic retrofitting and other repairs as part of the purchase agreement, or to adjust the price to account for work you’ll need to commission.
I’ve seen buyers walk into situations where “minor cosmetic damage” turned out to be symptomatic of serious structural issues. A few thousand dollars spent on a thorough inspection can save you tens of thousands—or help you avoid a bad purchase entirely.
Understanding Earthquake Safety (and Your Checklist)
You’ve seen this in disaster movies. Or maybe news reels during hurricane season in the tropics. There will be a weather event or natural disaster of some kind, and people race at the last minute looking for supplies – when only empty shelves exist.
If you’ve got a family, last-minute scrambles never work. It’s always best to have a plan in place before anything occurs so you and yours know exactly what to do.
Here’s what belongs in your earthquake preparedness plan:
Communication Strategy
Cell service will likely be down or overloaded after a significant earthquake. Charged walkie-talkies or two-way radios give you reliable communication when phones don’t work. Designate a meeting place if your family gets separated and communications are down. Choose someone outside the immediate area as an secondary emergency contact for kids if immediate friends and family cannot be reached.
Emergency Supplies
Keep disaster supplies in convenient, accessible locations. This includes battery-powered or hand-crank lighting, a well-stocked first aid kit, prescription medications (rotate these to keep them current), non-perishable food and water for at least 72 hours, and yes, even flare guns if you’re in a more remote area where signaling for help might be necessary.
Don’t neglect your car. You could become trapped, or you could be called upon to rescue a trapped motorist. Your center console needs to have critical tools available, such as a seatbelt cutter and glass breaker, a multi-tool, basic first-aid supplies, and a few power bars.
Home Safety Measures
Secure furniture, TVs, and heavy items that could fall during shaking. Install latches on cabinets to prevent glass and dishes from becoming projectiles. Know where your gas main shutoff is and keep a wrench next to it. If you smell gas after an earthquake, you need to be able to shut it off immediately. Renters should ask landlords about the building’s gas shutoff location.
Pets. They become victims, too. Don’t forget about them and know where their medications are and consider having pet transport available so that they feel safe and secured if you need to take them on the road.
Important Documents
Organize insurance policies, property deeds, medical records, and financial documents in a waterproof, portable container. Digital backups stored in the cloud give you access even if physical documents are destroyed. Anything worth saving could also be stored in a heavy-duty safe or Pelican-style case.
Practice the Plan
Run through earthquake drills with your family. Drop, cover, and hold on when shaking starts. Stay inside until it stops. Don’t rush to run outside during the event as to avoid falling utilities, out of control vehicles, and more. Be on the alert for aftershocks, which can be powerful enough to cause additional damage.
The San Francisco Department of Emergency Management offers presentations on disaster preparedness. Sign up for AlertSF to receive updates before, during, and after emergencies. In a major event, the city will share official information.
Seismic Retrofitting As Part of Your San Francisco Home Remodel Or Renovation
Here’s where seismic retrofitting intersects with the work we do every day: whole-house remodels and additions.
When you’re already opening walls, updating systems, and reconfiguring your home, that’s the ideal time to address seismic vulnerabilities. In fact, it will usually be required. You’re affecting the foundation. The framing is exposed. You’re already working with structural engineers and pulling permits.
Integrating seismic retrofitting into a larger renovation makes practical and financial sense, because it is usually absorbed into and done in conjunction with the work you are doing. You’re not paying for mobilization twice. You’re not coordinating separate contractor schedules. The work happens as part of a comprehensive approach to making your home safer, more functional, and code-compliant.
This is where the feasibility study we always start with becomes especially valuable. We assess your site, your structure, and your goals. We will provide preliminary guidance on the structural/seismic implications for your project. No surprises six months into construction. No discovering structural code complications after you’ve committed to a design that doesn’t account for city requirements.
I can’t tell you how many times proper upfront assessment has prevented expensive mid-project changes. When you know what the structural ramifications will be, you design accordingly. The seismic work becomes part of an elegant solution, not a reactive add-on.
Seismic Retrofitting Support for San Francisco Bay Homeowners
We get it. Nobody likes to think about earthquakes, but in California, being prepared is always a good idea.
If you’d like to explore ways that our architecture firm can support you with earthquake safety and seismic retrofitting compliance, drop us a line and we’ll get right back to you. We’ve been designing such spaces for over 25 years, and as San Francisco residents, we’re right there with you.
Schedule a complimentary Design Discovery Session and we’ll assess what your specific situation requires. No obligation, no pressure, just honest guidance from people who know San Francisco’s building requirements and earthquake realities inside and out.