Soft Story Retrofit Guide: Bay Area Costs, Ordinances, and Grants

What Makes a Building “Soft Story”?

The term “soft story” describes a specific structural weakness that is extremely common in Bay Area construction. If you have ever driven through neighborhoods in San Francisco, Oakland, Berkeley, or the hillside communities of the South Bay, you have seen thousands of soft story buildings without realizing it.

A soft story exists when one level of a building is significantly less rigid than the levels above it. In engineering terms, that level has inadequate lateral force resistance. It cannot handle the side-to-side forces generated by earthquake shaking as well as the rest of the building.

The most recognizable example is a two-story home with a two-car garage on the ground level. The garage door opening spans 16 to 18 feet, sometimes wider. That opening removes most of the structural wall area on one side of the building. The living space above has full walls, windows, and framing on all sides, making it relatively stiff. The ground floor, with its gaping opening, is the weak link.

During an earthquake, the upper floors want to move in one direction while the ground floor lacks the strength to keep up. The result can be catastrophic: the ground floor collapses, the upper floors drop, and the building pancakes. This exact failure pattern was documented extensively after the 1989 Loma Prieta earthquake, when numerous soft story buildings in San Francisco’s Marina District collapsed or were condemned.

Common Soft Story Configurations in the Bay Area

Tuck-under garages. The classic soft story. A one- or two-car garage occupies the ground floor, with living space directly above. This is the most common configuration in homes built from the 1950s through the 1970s throughout the South Bay, Peninsula, and East Bay.

Hillside homes on stilts. In communities like the Oakland Hills, Berkeley Hills, Saratoga, and Los Gatos, many homes are built on sloped lots with the downhill side supported by posts or columns. The open space beneath the main living level creates a soft story condition. These homes often have significant structural exposure due to the height of the stilts.

Multi-unit buildings with ground-floor parking. Apartment buildings and condominiums with open parking on the ground level and residential units above are a major soft story category. San Francisco’s mandatory retrofit program specifically targets this building type.

Split-level homes. Some split-level designs create a soft story condition at the lowest level, particularly when that level includes a garage and the upper levels are offset at different heights.

Commercial ground floor with residential above. Mixed-use buildings with storefronts, restaurants, or retail on the ground floor and apartments above often have a soft story condition due to the large window and door openings at street level.

How Soft Story Retrofits Work

A soft story retrofit strengthens the weak ground floor so it can resist the lateral forces generated by earthquake shaking. There are several engineering approaches, but the most common solution for residential buildings is the steel moment frame.

Steel Moment Frames

A steel moment frame consists of heavy steel columns and a beam connected with rigid, welded joints. “Moment” refers to the frame’s ability to resist rotational forces at its connections, meaning the frame can absorb and transfer earthquake energy without the columns separating from the beam.

For a typical tuck-under garage, one or two moment frames are installed within or adjacent to the garage door opening. The frames are anchored to a reinforced concrete foundation below and connected to the floor framing above. The key advantage of a moment frame is that it provides the necessary lateral strength without filling in the garage opening. You keep your garage functional while gaining earthquake protection.

Moment frames are fabricated in a steel shop based on the structural engineer’s design, then delivered to the site for installation. Each frame typically weighs 500 to 1,500 pounds and requires a small crane or equipment to position.

Structural Shear Walls

In some cases, adding plywood shear walls to portions of the ground floor is sufficient or preferable to moment frames. Shear walls are panels of structural plywood nailed to wood framing with a specific nailing pattern that provides lateral resistance. They are less expensive than steel moment frames but require solid wall area, which means they cannot span across a garage opening.

Shear walls are often used in combination with moment frames. The moment frame handles the large opening, while shear walls reinforce adjacent walls that do not need to remain open.

Foundation Upgrades

Soft story retrofits frequently require foundation modifications. The new steel moment frames and shear walls transfer significant forces to the foundation, which must be strong enough to handle those loads. Common foundation upgrades include:

• New reinforced concrete footings beneath moment frame columns
• Thickened or reinforced existing foundation walls
• New tie-downs and hold-down anchors connecting the wood framing to the concrete
• Foundation bolting of the sill plate if not previously completed

Foundation work is usually the most disruptive part of a soft story retrofit because it involves excavation, forming, rebar installation, and concrete pouring.

Connection Hardware

Modern seismic connection hardware (Simpson Strong-Tie and similar products) ties all the retrofit components together. Hold-down bolts anchor vertical framing members to the foundation. Shear transfer ties connect floor diaphragms to the new shear walls and moment frames. These connections ensure that earthquake forces travel through the entire structural system rather than concentrating at weak points.

Bay Area Soft Story Ordinances

Several Bay Area cities have enacted mandatory soft story retrofit ordinances, recognizing the significant life-safety risk these buildings pose. Understanding which ordinance applies to your property is important because non-compliance can result in fines, restrictions on rental, and liability exposure.

San Francisco

San Francisco’s Mandatory Soft Story Retrofit Program, established in 2013 under the Building Code, is the most comprehensive in the Bay Area. The program targets wood-frame buildings with five or more residential units and two or more stories that have a soft, weak, or open-front condition at the ground floor.

The program was implemented in four tiers based on building size, with larger buildings required to retrofit first. As of 2026, most compliance deadlines have passed, and the city actively enforces non-compliance with penalties. The Department of Building Inspection (DBI) maintains a public list of buildings subject to the ordinance and their compliance status.

San Francisco’s program has been widely cited as a model for other California cities. It has resulted in the retrofit of thousands of multi-unit buildings across the city.

Oakland

Oakland adopted a mandatory soft story retrofit ordinance targeting multi-unit residential buildings. Similar to San Francisco, the ordinance focuses on wood-frame buildings with ground-floor parking or commercial space and residential units above. Oakland’s program includes phased compliance deadlines based on building size and the number of units.

The city’s Building Bureau administers the program and provides guidance to property owners on compliance requirements.

Berkeley

Berkeley’s soft story retrofit requirements cover multi-family buildings with soft story conditions. The city has been particularly proactive given its proximity to the Hayward Fault, which runs directly through the city and is considered one of the most dangerous faults in the country. Berkeley’s program includes mandatory screening of potentially vulnerable buildings and retrofit requirements for those that do not meet current standards.

Other Bay Area Cities

While San Francisco, Oakland, and Berkeley have the most established mandatory programs, other Bay Area cities are considering or implementing their own soft story retrofit requirements. Fremont, Hayward, and San Jose have all studied the issue, and state-level legislation (including AB 1857) has pushed for broader mandatory retrofit requirements across California.

Even in cities without a mandatory ordinance, homeowners with soft story conditions face significant risk. Voluntary retrofitting is strongly recommended, particularly for homes near active fault lines.

Soft Story Retrofit Costs: What to Expect

The cost of a soft story retrofit varies significantly depending on the building’s characteristics. Here is a breakdown of typical costs for Bay Area residential projects.

Cost Ranges by Building Type

Single-family home with tuck-under garage (1-2 car):

• Steel moment frame(s): $8,000 to $15,000
• Foundation upgrades: $3,000 to $8,000
• Engineering design: $3,000 to $6,000
• Permits and inspections: $1,500 to $3,000
• Total: $15,000 to $30,000

Single-family hillside home with open lower level:

• Steel moment frames (multiple): $12,000 to $25,000
• Foundation upgrades: $5,000 to $15,000
• Engineering design: $5,000 to $10,000
• Permits and inspections: $2,000 to $4,000
• Total: $25,000 to $50,000+

Multi-unit building (4-8 units):

• Steel moment frames: $20,000 to $50,000
• Foundation upgrades: $10,000 to $25,000
• Engineering design: $8,000 to $15,000
• Permits and inspections: $3,000 to $6,000
• Total: $40,000 to $100,000+

Key Cost Drivers

Number of moment frames. Each steel moment frame costs $4,000 to $12,000 installed, depending on size and load requirements. Buildings with multiple large openings need multiple frames.

Foundation condition. If the existing foundation is in good condition and only requires new footings for the moment frame columns, costs are lower. If the foundation needs significant repair or reinforcement, costs increase substantially. Homes with termite damage to foundation-area framing may need additional repair work before the retrofit can proceed.

Site access. Tight sites, hillside lots, and buildings with limited access for equipment increase labor costs. In dense San Francisco neighborhoods, staging materials and getting equipment to the work area can be challenging.

Engineering complexity. Simple tuck-under garage retrofits with standard moment frame solutions require less engineering time. Hillside homes, irregular building shapes, and multi-unit buildings require more complex analysis.

Permit processing time. While not a direct cost, extended permit review timelines (common in San Francisco) increase overall project duration, which can affect scheduling and general conditions costs.

The ESS Grant Program

California’s Earthquake Soft-Story (ESS) grant program, administered by the California Residential Mitigation Program (CRMP), provides financial assistance to homeowners retrofitting soft story buildings.

ESS Grant Details

• Maximum grant amount: $13,000
• Eligible buildings: Wood-frame residential buildings with a soft story condition
• Eligible work: Engineering design, construction of steel moment frames, shear walls, foundation upgrades, and related structural work required for the soft story retrofit
• Income requirement: No income restriction (unlike the supplemental EBB grant)
• Application process: Online enrollment through the CRMP website during open enrollment periods

How to Apply

1. Check program enrollment status at the CRMP website
2. Submit an application during an open enrollment period
3. If accepted, hire a licensed contractor to perform the work
4. The contractor completes the retrofit per program standards
5. The grant is paid upon verification of completed work

The ESS grant can be combined with the CEA earthquake insurance retrofit discount for additional savings. A homeowner who receives a $13,000 ESS grant and then qualifies for a 25% CEA premium discount maximizes the financial return on their retrofit investment.

EBB vs. ESS: Which Grant Applies?

The EBB (Earthquake Brace + Bolt) program and the ESS (Earthquake Soft-Story) program cover different types of retrofits:

• EBB covers standard brace-and-bolt retrofits: foundation bolting and cripple wall bracing for raised-foundation homes. Grants up to $3,000 (plus up to $7,000 supplemental for income-eligible households).
• ESS covers soft story retrofits: steel moment frames and related structural work for buildings with soft story conditions. Grants up to $13,000.

If your home has both a raised foundation needing bolting and a soft story condition, you may be eligible for both programs. Discuss this with your contractor and check current program eligibility requirements. For more on the standard brace-and-bolt approach, see our comprehensive seismic retrofit guide for Bay Area homes.

Soft Story Retrofit Timeline

Understanding the full timeline helps you plan and set expectations.

Phase 1: Engineering Design (3 to 6 Weeks)

A licensed structural engineer evaluates your building, designs the retrofit solution, and produces construction drawings. This includes:

• Site visit and existing conditions assessment
• Structural analysis of the building under seismic loading
• Design of moment frames, shear walls, and foundation upgrades
• Production of stamped construction drawings for permit submittal

Choose an engineer experienced with residential soft story retrofits in your specific city. Local experience matters because each jurisdiction has different submittal requirements and plan review expectations.

Phase 2: Permitting (4 to 12 Weeks)

Your contractor or engineer submits the retrofit plans to the local building department for review. Review timelines vary significantly:

• San Jose: 4 to 6 weeks for standard plan review
• Oakland: 6 to 10 weeks
• San Francisco: 8 to 12 weeks or longer
• Smaller jurisdictions (Los Gatos, Saratoga, Menlo Park): 3 to 6 weeks

Some jurisdictions offer expedited review for seismic safety projects. Ask your contractor whether this option is available for your project.

Phase 3: Construction (4 to 8 Weeks)

Active construction for a typical single-family soft story retrofit involves:

Week 1-2: Foundation work. Excavate for new footings, install rebar cages, pour concrete for moment frame foundations. Concrete cures for 7 to 14 days before frame installation.

Week 2-3: Steel frame installation. Moment frames are delivered and set in place with equipment. Frames are welded or bolted per the engineering design. Connections to the foundation and upper floor framing are completed.

Week 3-5: Shear walls and connections. Structural plywood shear walls are installed where specified. Hold-down hardware, anchor bolts, and shear transfer connections are installed throughout.

Week 5-6: Inspections and finishing. Building inspectors verify the work at multiple stages. After final inspection, any disturbed finishes (drywall, stucco, paint) are repaired.

Week 6-8: Punch list and closeout. Final finish work, cleanup, and project documentation.

During construction, you will typically lose use of the garage for 4 to 6 weeks. Plan accordingly for vehicle parking. The rest of the home usually remains habitable throughout the project.

When a Soft Story Retrofit Is Required vs. Recommended

Mandatory Situations

• Your building falls under a local soft story retrofit ordinance (check with your city’s building department)
• You are selling the property and the buyer’s lender requires a retrofit as a condition of the loan
• You are refinancing and the lender identifies a soft story condition during the appraisal
• Your city issues a specific retrofit notice for your property

Strongly Recommended Situations

• Your home has a tuck-under garage and was built before 1980
• You live on a hillside lot with an open lower level
• Your home is located within a mapped fault zone
• You are planning a remodel or addition that will involve work on the ground floor
• You want to qualify for the CEA earthquake insurance discount
• You are preparing your home for sale and want to maximize buyer confidence

Choosing a Soft Story Retrofit Contractor

Not all general contractors have experience with soft story retrofits. This is specialized structural work that requires specific knowledge and equipment. When selecting a contractor:

Verify seismic retrofit experience. Ask for references from previous soft story retrofit projects, specifically in the Bay Area. Request photos of completed work showing moment frame installations.

Confirm licensing and insurance. Your contractor must hold a valid California Contractor’s State License (B General Building or C-General Engineering). Verify the license at the CSLB website.

Check their engineering relationships. Experienced seismic retrofit contractors work closely with structural engineers who specialize in retrofit design. A good contractor can recommend engineers or may have in-house engineering capabilities.

Understand their permitting experience. Contractors familiar with your city’s building department know the submittal requirements, the plan reviewers, and the inspection process. This experience can significantly reduce delays.

Get detailed proposals. A proper soft story retrofit proposal should include engineering scope, specific moment frame details, foundation work, connection hardware, permit costs, and a construction timeline. Vague proposals that lack engineering detail are a red flag.

Custom Home Design and Build specializes in seismic retrofitting for Bay Area homes, including soft story retrofits. Our team handles the full process from engineering through final inspection. Contact us for a consultation on your soft story retrofit project.

Protecting Your Investment

A soft story retrofit is a significant investment, but it addresses a structural vulnerability that can lead to catastrophic loss. The combination of mandatory ordinances, available grant funding, insurance premium discounts, and the fundamental safety benefit makes soft story retrofitting one of the most important structural improvements a Bay Area homeowner can make.

If your home has a garage on the ground floor with living space above, or if it is built on a hillside with an open lower level, get an assessment from a qualified structural engineer. Understanding your home’s specific risk level is the first step toward making an informed decision about retrofitting.