Structural engineering · San Francisco, CA

Structural engineer in San Francisco, California

Connect with engineering firms serving San Francisco. From mandatory soft-story retrofit compliance and hillside retaining walls to ADU calculations, beam designs, and historic building structural assessment.

Also searched as: residential structural engineer San Francisco CA · San Francisco County structural engineer · stamped structural calculations San Francisco · soft-story retrofit engineer San Francisco · structural engineer near me San Francisco CA

Find an engineer in San Francisco Start a beam design

Local code & loads

San Francisco building code & ASCE 7 design loads

San Francisco enforces the 2025 California Building Code (CBC) with San Francisco Building Code ammendments, based on the 2024 IBC. Stamped calculations submitted for permit reference the design parameters below.

Values shown for reference only — project-specific values from the ASCE 7 Hazard Tool should be used for engineering design at the actual project address.

ASCE 7 design parameters

Default values used for most residential and light-commercial projects in San Francisco. Site Class and seismic spectral values may shift based on geotechnical investigation.

Building code	2025 California Building Code (CBC) with San Francisco Building Code ammendments, based on the 2024 IBC
ASCE 7 edition	ASCE 7-22
Seismic Sₛ	1.56g
Seismic S₁	0.60g
Site class	Default
SᴅS	1.20g
Sᴅ₁	1.16g
Seismic Design Category	D
Ultimate wind speed	92 mph
Ground snow load	0 psf

Risk Category II assumed for typical residential and light commercial use — confirm with your engineer if the occupancy or use may require a higher category.

San Francisco is one of the most seismically complex urban environments in North America. The city sits between the San Andreas Fault (offshore to the west) and the Hayward Fault (across the Bay to the east); both are capable of major ruptures affecting the city simultaneously. Geologically, the city is highly heterogeneous: bedrock outcrops in Twin Peaks and Diamond Heights behave very differently under seismic loading than soft Bay mud in SoMa and the Mission, or the hydraulic fill underlying the Marina; which liquefied in both 1906 and 1989. Wind exposure on west- and north-facing building faces is significant

Common projects engineers design in San Francisco

The work engineers handle frequently in San Francisco and the surrounding San Francisco County.

Load-bearing wall removals and open-concept remodels
Accessory Dwelling Units (ADUs) and garage conversions (in-law units)
Mandatory soft-story retrofit compliance (pre-1978 multi-family)
Seismic retrofit of wood-frame Victorians and Edwardians
Foundation design for Bay mud, fill, and variable bedrock
Hillside retaining walls and slope stabilization
Second-story and rooftop additions (vertical expansion)
Deck and balcony structural repair and replacement
Rooftop solar and green-roof structural verification
Historic building structural assessment and preservation engineering

What's different about San Francisco

Local conditions that affect structural design

City-specific factors that show up in many San Francisco calculations — and the things plan reviewers look for.

San Francisco's dense, largely Victorian and Edwardian housing stock creates a structural engineering market unlike anywhere else in California. Thousands of wood-frame houses (many with cripple-wall foundations, unbraced soft stories above garage parking, and insufficient anchor bolting) are candidates for seismic retrofit. The city's Mandatory Soft-Story Retrofit Program has driven significant activity for licensed structural engineers, and voluntary retrofits of single-family homes remain common when owners undertake other renovation projects.

San Francisco's soil conditions are among the most variable in the Bay Area. Bedrock outcrops in the Castro, Noe Valley, Twin Peaks, and Potrero Hill behave very differently under seismic loading than the soft Bay mud in SoMa and the Mission, or the hydraulic fill that underlies the Marina and parts of the Financial District. The Marina District liquefied in both the 1906 earthquake and the 1989 Loma Prieta event; dramatic illustrations of how soil type can dominate building performance during a major earthquake. A geotechnical investigation is standard practice for any significant foundation work in fill or mud zones.

The city's building conversion market is robust: vertical additions on flat-roofed Edwardians, garage conversions to ADUs (in-law units), and rear additions are all common project types. San Francisco's planning code adds complexity; historic district overlays, Discretionary Review, and design standards in some neighborhoods mean the structural engineer often works alongside a planning consultant and architect, not just DBI.

Wind loads are an underappreciated factor in San Francisco structural design. The city's west- and north-facing neighborhoods (the Outer Sunset, the Richmond, Twin Peaks) experience sustained and gusting winds much higher than the Bay Area inland average. Roof decks, rooftop additions, and solar array anchorages on exposed building faces warrant careful wind analysis.

Permits

Where to submit your San Francisco permit

Stamped calculations from clearspan are submitted directly to the City and County of San Francisco — Department of Building Inspection (DBI). Most residential structural submittals are reviewed online.

Building department

City and County of San Francisco — Department of Building Inspection (DBI)

49 South Van Ness Ave, San Francisco, CA 94103

(628) 652-3700

Visit the building department →

Submittal notes

San Francisco's Department of Building Inspection (DBI) is the sole permitting authority; the city and county are coterminous. DBI has a Mandatory Soft-Story Retrofit Program for wood-frame multi-family buildings built before 1978; compliance is required in phased tiers based on number of units. San Francisco has numerous historic districts and design-review overlays that may add planning review steps to structural projects.

FAQ

Structural engineering in San Francisco — FAQs

The questions San Francisco contractors and homeowners ask most often.

What is San Francisco's Mandatory Soft-Story Retrofit Program?+

San Francisco requires owners of certain wood-frame multi-family buildings built before 1978 to retrofit them for seismic safety; targeting the 'soft story' created by open parking or commercial space at the ground floor beneath residential units above. The program is phased by number of units. A licensed structural engineer prepares the design; DBI reviews and issues the permit. clearspan can connect you with an engineer experienced with this program.

Do I need a structural engineer to add an in-law unit in San Francisco?+

Yes; garage conversions and ADUs in San Francisco require PE-stamped structural plans as part of the building permit. The structural scope typically includes the floor framing over the converted garage space, any new walls, and a review of the building's seismic load path above. DBI will not issue a permit without stamped drawings for structural scope.

My San Francisco home is in a historic district; does that affect the structural work?+

It can. Historic district designation typically means Planning Department review for exterior work, separate from DBI. Structural repairs and retrofits done entirely inside the building generally aren't affected, but any exterior modification (windows, additions, rooflines) may trigger historic review. Coordinate with your architect and the Planning Department early in the project.

Nearby cities

Structural engineers in other San Francisco Bay Area cities

Browse city pages for nearby jurisdictions.

Concord, CA→Fremont, CA→Oakland, CA→San Jose, CA→Bakersfield, CA→Citrus Heights, CA→

Find a structural engineer →Structural engineering services →Structural engineering guides →For engineering firms →

Need a beam designed quickly in San Francisco?

Submit your project details and get a design in minutes, then submit to a licensed California engineer for review.

Get started