Frequently Asked Questions
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Avant-Garde Construction Enterprise is fully licensed, insured, and bonded. Matthew
Gatterman is a second-generation San Francisco Bay Area seismic retrofit contractor
and has spent his entire life involved with seismic retrofit, drainage, and
foundation projects in the Bay Area (his father started specializing in seismic
retrofits in 1992 after spending 20 years as a new-construction development contractor
across three different states).
From “crawl space only retrofits” of flat-lot homes to complete foundation
replacements to “entire building retrofits of”: five-story steep hillside homes,
apartment complexes, beach-front properties, and even complex cantilevered cliff-side
homes, we have done it all (including retrofitting hundreds of “retrofitted”
homes that were done incorrectly). It is rare to find anyone as experienced.
We provide detailed proposals, professional site visits, and have excellent
5-star reviews from local clients. We treat every home like it is our own.
No seismic retrofit project is too simple or too complex. Whether your retrofit is a one-day project or a one-year project, we can handle it.
Seismic retrofitting is the process of modifying an existing structure to
make it more resistant to earthquakes. This typically involves reinforcing
the foundation, cripple walls, and connections between structural elements
to create a continuous load path.
The USGS estimates a 72% chance of a major earthquake (6.7 or greater) in
the Bay Area within the next 18 years. Many homes lack proper
reinforcement, putting them at risk for significant damage.
Our consultations include a thorough site assessment, professional
photographs, detailed notes and drawings, and itemized recommendations.
You’ll receive a to-scale drawing of your home and a comprehensive
proposal.
We provide free preliminary estimates via email if you share your address,
photos, and project details. Please note, site visit clients are
prioritized for scheduling and proposals. Please schedule a site visit to
guarantee service. For a detailed, written proposal and site visit, there
is a fee based on your location.
We specialize in: Learn more about our services
The EBB & ESS programs offer state-sponsored grants that help
homeowners pay for seismic retrofits. Learn more here.
A soft-story retrofit strengthens buildings with large openings (like
garages) on the ground floor. A crawl space retrofit focuses on
reinforcing the foundation and short walls beneath the main floor.
Foundation repair/replacement refers to the process of fixing or completely
rebuilding the base structure that supports your home. The foundation is
critical for the stability and safety of your house, especially in
earthquake-prone areas like the Bay Area.
Foundation repair or replacement ensures your home remains safe, level, and
structurally sound—protecting it from earthquakes and other hazards.
A French drain is a trench lined with filtration fabric then filled with ¾”
drainage rock, and contains a perforated pipe that redirects surface water and
groundwater away from your home’s foundation or crawl space– to help prevent
water from pooling around your foundation, which can cause damage or flooding.
French Drains are commonly installed along the perimeter of a home or in areas
with poor drainage.
A sump pump is a mechanical device installed in a pit (sump basin) that ejects
subterranean water away from your home, usually to a storm drain or dry-well.
Sump-pumps are essential for homes with water intrusion issues or high groundwater
tables that cannot use gravity for ejection lines to the street gutter.
A dry-well is an underground structure that collects and disperses water from
sources like French Drains or sump pumps. Dry-wells allow water to slowly
percolate into the surrounding soil, reducing surface runoff and preventing
flooding. They are often used in conjunction with French drains and sump pumps
for comprehensive drainage solutions.
In summary, French Drains, sump pumps, and dry-wells work together to keep your
foundation dry and protected from water damage.
A moment frame is a steel frame designed to resist lateral (sideways) forces—like
those from earthquakes—while allowing for large openings (such as garage doors)
in a building’s wall. Consists of vertical steel columns and horizontal steel
beams, rigidly connected. Used in “soft-story” retrofits to strengthen weak
ground floors without closing off open spaces. Helps prevent collapse by
absorbing and transferring earthquake forces.
A moment column is a vertical structural element that supports the weight of the
building above it. In seismic retrofits, steel columns are often added to
reinforce areas with large openings or weak points. Columns work with beams
and moment frames to provide strength and stability.
Structural steel refers to steel components (beams, columns, frames, etc.)
used to reinforce or build parts of a structure. Provides exceptional
strength and flexibility, making it ideal for earthquake resistance.
Used in retrofits to support sagging floors, brace cripple walls, or
create moment frames.
To summarize, moment frames, columns, and structural steel are essential tools
in seismic retrofitting—especially for homes or buildings with large openings
or unique layouts. They provide the strength and flexibility needed to keep
structures safe during earthquakes.
We use structural steel, plywood, engineered lumber, structural screws, and
specialized seismic connectors (brackets, plates, bolts, hold-downs,
etc.), all installed to meet or exceed building codes.
You may need engineered plans for complex projects (e.g., 3+ stories, tall
cripple walls, or soft-story retrofits). We can recommend experienced
engineers if needed.
Yes! The EBB and ESS programs offer grants for qualifying retrofits. We also
offer referral rebates—$100 for each successful referral.
Most standard retrofits are completed in 1–3 days, depending on the size
and complexity of the project. Advanced projects may take weeks or months–
complete foundation replacements, entire-home-retrofits of complex
hill-side homes, etc.
In most cases, you can remain in your home during the retrofit. Work is
typically done in the crawl space or garage, minimizing disruption. When
work is done in your living space, we will use floor protection and
plastic to section-off work areas and protect your home.
A cripple wall is the short wall between your home’s foundation and the
first floor. It’s often the weakest part of older homes and a common
failure point during earthquakes. Reinforcing cripple walls by creating
shear walls is a key part of retrofitting.
A shear wall is a structural wall designed to resist lateral (sideways)
forces caused by wind or earthquakes. In residential seismic retrofits,
shear walls are typically made by attaching plywood panels to the inside
of the stud-framed walls in the crawl space or garage.
Key points about shear walls:
A continuous load path connects all parts of your home—roof, walls,
floors, and foundation—so earthquake forces are safely transferred down to
the ground. This prevents structural failure during a quake.
We use premium seismic hardware such as structural screws, seismic
connectors, anchor bolts, and hold-downs—often exceeding minimum code
requirements for added safety.
A structural screw is a heavy-duty, high-strength screw specifically
designed for use in construction and structural applications, including
seismic retrofits.
Key facts about structural screws:
A seismic connector is a specialized piece of hardware used to
strengthen the connections between different parts of a building’s
structure, helping the home move as a single unit during an earthquake.
Key facts about seismic connectors:
An anchor bolt is a heavy-duty fastener used to securely connect a building’s
wood framing (usually the mudsill) to its concrete foundation.
Key facts about anchor bolts:
A hold-down is a heavy-duty steel bracket used in seismic retrofits to
anchor the ends of shear walls or other structural elements to the foundation.
Key facts about hold-downs:
In summary, hold-downs are essential for keeping your home’s walls securely
anchored to the foundation during seismic activity.
A plywood panel is a flat sheet made from thin layers (plies) of wood
veneer that are glued together, with the grain of each layer running
perpendicular to the previous one. This construction gives plywood its strength
and stability.
In seismic retrofits:
Plywood panels are a key material in seismic retrofits, used to reinforce walls
and improve your home’s earthquake resistance.
If your home was built before the 1980s, has a raised foundation, or has a
crawl space or soft-story (living space over a garage), it likely needs a
retrofit. We can assess your home and provide recommendations.
We’re happy to review previous work! Please email us photos and any
available plans, and we’ll provide recommendations for any additional
improvements as soon as we can.
Please note, site visit clients are prioritized for scheduling and
proposals. Please schedule a site visit to guarantee service.
Yes! If you and a neighbor schedule retrofits on consecutive days, both of you
can receive a credit. We also offer rebates for successful referrals.
In most cases, you’ll receive a detailed, itemized proposal within 2–5 business
days after your site visit. Timing will be communicated when scheduling.
Yes! If you provide your address, contact info, and some photos or details
about your home, we can send a free preliminary estimate by email. Please
note, site visit clients are prioritized for scheduling and proposals.
Please schedule a site visit to guarantee service.
Most contractors simply skip these areas. We’re experienced with
challenging access situations and ensure your seismic retrofit is done
properly– no matter what.
Yes! If you already have engineered plans, please email them to sales@avant-gardece.com.
We’ll review them and provide a proposal as soon as we can.
Please note, site visit clients are prioritized for scheduling and proposals.
Please schedule a site visit to guarantee service.
Yes, Avant-Garde Construction is fully licensed, bonded, and insured for
all work performed.
Yes, we can assist with the permitting process and ensure all work meets
local building codes.
There will not be any issues discovered in any areas that were visible
during the site visit. We conduct thorough site visits to avoid this
possibility. If we discover unexpected conditions that were covered up by
existing plywood, stucco, and/ or drywall during the site visit (like dry
rot or termite damage), we’ll document them with photos and discuss repair
options before proceeding.
We do not offer in-house financing, but we do provide financing through
Acorn. You can check offers here:
https://www.acornfinance.com/pre-qualify/?d=TCLDX&utm_medium=web_pre_qual_banner
Many clients also use home equity loans or lines of credit. Additionally,
some government programs may offer grants or low-interest loans for
seismic upgrades.
Day-to-day, we serve the entire Greater San Francisco Bay Area. If you’re
outside this area, we can still accommodate– let us know and we’ll advise on
next steps.
A properly retrofitted home is often more attractive to buyers and may
increase your property value, especially in earthquake-prone areas.
Many insurance companies offer discounts for homes that have been
professionally retrofitted.
Yes! After your retrofit, we will provide documentation and photos for
your insurance company, which may help you qualify for discounts.
Yes, Avant-Garde Construction provides warranties on workmanship and materials.
Details will be included in your proposal.
We have experience working with historic homes and can recommend retrofit
solutions that preserve your home’s character while improving safety.
Absolutely! We’re happy to collaborate with your existing team to ensure your
retrofit integrates smoothly with other renovations or repairs.
We accept checks, credit cards, and electronic payments such as Zelle. Payment
details will be outlined in your proposal.
You can book a consultation directly through our online booking system, email,
or phone.
Retrofits for brick or stone foundations are more complex and may
require engineered solutions. We can assess your home and recommend the
best approach.
The average cost for a minimum-requirement crawl space seismic retrofit in the
Bay Area can range anywhere from $4,000-$40,000+ for most single-family homes.
The final price depends on factors like:
For a more accurate estimate, we recommend a site visit, which includes a
detailed assessment, professional photos, and a written proposal.
Clear access to the crawl space, garage, or basement is helpful. Move
personal items away from work areas and let us know about any pets or special
concerns.
When planning earthquake retrofits for your home, consider the following key
factors:
We go beyond minimum code requirements, providing comprehensive
assessments, detailed proposals, and premium hardware. Our team has
completed over 3,000 retrofits and is highly rated by clients.
Great question! The best options for seismic retrofits in the San Francisco
Bay Area depend on your home’s structure, age, and specific vulnerabilities.
Here are the most effective and commonly recommended retrofit solutions:
Top Seismic Retrofit Options for Bay Area Homes 1. Crawl Space Retrofits
Bolting
the mudsill (the wood framing at the base of your home) to the concrete
foundation.
Installing
seismic connectors to attach the floor framing to the mudsill / cripple
walls. When you have cripple walls, these attach the top of the walls to
the floor framing. When you do not have cripple walls, these attach the
mudsill directly to the floor framing.
Adding
plywood shear panels to cripple walls for lateral strength.
Installing
hold-downs for uplift and overturning protection.
2. Soft-Story Retrofits
Installing
steel moment frames or proprietary shear walls in buildings with large
garage openings or open ground floors.
Reinforcing
columns and beams to prevent collapse during an earthquake.
3. Earthquake Brace + Bolt (EBB) Retrofits
Standardized
retrofit for older homes, involving foundation bolting and bracing cripple
walls.
Qualify
for state grants.
4. Foundation Repair or Replacement
Replacing
or repairing damaged, cracked, or unreinforced foundations.
Upgrading
to meet current seismic codes.
5. Structural Steel Upgrades
Adding
steel beams, columns, or moment frames for additional strength, especially
in multi-story or complex buildings.
6. Engineered Solutions
Custom
retrofits designed by a structural engineer for unique or complex homes,
including hillside properties or those with irregular layouts.
Bonus:
Always
use code-compliant, high-quality hardware (like Simpson Strong-Tie
products).
Work
with experienced local contractors familiar with Bay Area building codes
and soil conditions.
Yes, there are specific regulations for soft-story retrofits in the San
Francisco area.
San Francisco has a Mandatory Soft-Story Retrofit Program that
requires certain multi-unit, wood-frame buildings with a “soft-story”
condition (typically, buildings with large openings like garages on the
ground floor and residential units above) to be seismically strengthened.
This ordinance applies to buildings built before 1978 with five or more
residential units and at least two stories over a “soft” or open front.
Key points:
Finding a reliable contractor for foundation replacement in the Greater San
Francisco Bay Area is crucial for your home’s safety and investment.
Here are some steps and tips to help you choose wisely:
Why Consider Avant-Garde Construction Enterprise?
What is seismic retrofitting?
Why is seismic retrofitting important in the Bay Area?
What does a retrofit consultation include?
Do you offer free estimates?
What types of projects do you handle?
What are the Earthquake Brace + Bolt (EBB) & Earthquake Soft-Story (ESS) programs?
What is the difference between a “soft-story” and a “crawl space” retrofit?
What is foundation repair/ replacement?
Foundation Repair
Foundation Replacement
What are French Drains, Sump-Pumps, and Dry-Wells?
What are moment frames, columns, and structural steel?
What materials do you use?
Do I need engineered plans?
Are there rebates or incentives?
How long does a typical seismic retrofit take?
Will I need to move out during the retrofit?
What is a cripple wall, and why is it important?
What is a shear wall?
What is a “continuous load path” and why does it matter?
What kind of hardware do you use?
What is a structural screw?
What is a seismic connector?
What is an anchor bolt?
What is a hold-down?
What is a plywood panel?
How do I know if my home needs a seismic retrofit?
What if my home already had some retrofit work done?
Can I get a discount if my neighbor also retrofits their home?
How soon will I get my proposal after a site visit?
Can I get a preliminary estimate without a site visit?
What if my crawl space or foundation is hard to access?
Do you work with engineered plans?
Are your crews licensed and insured?
Do you handle permits?
What happens if you find additional issues during the retrofit?
Do you offer financing?
What areas do you serve?
Can seismic retrofitting increase my home’s resale value?
Will seismic retrofitting lower my homeowner’s insurance premium?
Can you help with insurance documentation?
Do you provide warranties on your work?
What if my home is a historic property?
Can you work with my contractor or architect?
What payment methods do you accept?
How do I schedule a consultation?
Can you retrofit homes with brick or stone foundations?
What is the average cost of crawl space retrofits in the Bay Area?
How do I prepare my home for a retrofit project?
What should I consider when planning earthquake retrofits for my home?
Older homes (especially pre-1980s) and those with raised foundations, crawl
spaces, or soft-story designs are often most vulnerable.
Identify weak points such as cripple walls, unbolted mudsills, large openings
(garages), and unreinforced foundations.
Make sure your retrofit plan complies with local building codes and any
city-specific requirements (like San Francisco’s soft-story ordinance).
Some homes require engineered plans, especially if they have complex layouts,
multiple stories, or unique conditions.
Choose a contractor with extensive seismic retrofit experience and strong local
knowledge—like Avant-Garde Construction.
Costs can vary widely. Consider your budget, available rebates (like EBB/ESS),
and possible insurance discounts.
Most retrofits require permits. A reputable contractor will help with
permitting and inspections.
Plan for access to crawl spaces, garages, or basements. Most retrofits allow
you to stay in your home.
Keep records of all work, permits, and photos for insurance and resale
purposes.
A retrofit not only protects your family but can also increase your home’s
value and marketability.What sets Avant-Garde apart from other contractors?
What are the best options for seismic retrofits in the San Francisco Bay Area?
Are there specific regulations for soft-story retrofits in the San Francisco area?
How can I find a reliable contractor for foundation replacement in Greater San Francisco?