Custom ADU Builder San Francisco
Compare custom scope, site constraints, model options, finish level, construction sequence, and written pricing before selecting a build approach.
San Francisco County · California
San Francisco ADU design & construction
San Francisco separates State and Local ADU programs. Existing legal units, tenant housing services and the need for Planning Code waivers can change the appropriate application route.
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Custom ADU builder & contractor services in San Francisco
Start with a custom ADU builder or ADU contractor in San Francisco, then coordinate design, architecture, engineering, permits, budgeting, construction, inspections, and handoff around the property.
ADU Contractor San Francisco
Coordinate construction scope, subcontractors, schedule, inspections, site logistics, and closeout around a clearly defined permitted set.
ADU Design Build San Francisco
A coordinated design-build workflow keeps property review, design, engineering, permitting, budgeting, procurement, and construction aligned.
ADU Design San Francisco
Develop the floor plan, exterior direction, material selections, functionality, and site fit before committing to engineering and construction.
ADU Architect San Francisco
Architectural planning can address layout, massing, code constraints, site relationships, and permit drawings where an appropriately licensed professional is required.
ADU Engineer San Francisco
Engineering coordination can cover structural, foundation, utility, civil, energy, and other disciplines required by the property and permitting authority.
Local planning guide · Reviewed October 2, 2026
What matters for an ADU in San Francisco
Permitting authority: San Francisco Planning — ADUs
Official local guidanceLocal rules and design checks
| Topic | Local guidance |
|---|---|
| Program selection | San Francisco says State and Local ADU programs cannot be combined. |
| Housing services | Document garage, laundry and storage uses before conversion; removing tenant housing services has separate requirements. |
| Regulatory agreement | Local-program waivers can require a rent-control regulatory agreement before permit issuance. |
Selected local requirements, not a complete zoning determination. Confirm the current rules for your address with the responsible agency.
Fees and budget checks
Planning distinguishes application fees from development-impact fees, which DBI collects at the first construction document where applicable. Obtain the actual ADU assessment and any SFPUC charges; a citywide impact-fee change is not a blanket ADU permit waiver.
SF Planning development-impact fee guidanceHow to start the permit process
Check the legal unit record, identify the program and use the single-family or multifamily checklist. Coordinate Planning, DBI, Public Works and PUC review.
Municipal application examples
San Francisco’s two ADU checklists
Updated May 8, 2026, the checklists distinguish a single-family lot adding one ADU from multifamily and certain multi-ADU or waiver cases.
View the original sourceSan Francisco ADU questions
- Can I mix the Local and State programs?
- San Francisco expressly says they cannot be combined.
- Why does existing tenant storage matter?
- Converting it may remove a housing service; document the existing use and obtain the required review before designing around it.
Sources for this guide
- San Francisco Planning — ADUs
- SF Planning development-impact fee guidance
- San Francisco’s two ADU checklists
Local sources reviewed October 2, 2026. Historical examples retain their stated dates. Contact ADU California Inc. to confirm project availability; this guide does not establish an office location or property approval.
A useful first review
Separate what is available from what still needs verification.
01
Confirm the property
Start with a complete address and review the available parcel, building, and map context.
02
Identify the unknowns
Keep missing setbacks, easements, utilities, access, hazards, and local requirements visible.
03
Choose the next review
Use the preliminary result to prepare a focused conversation with the required professionals and agencies.
Explore project types
Compare the scope before choosing a solution.
These pages explain the questions each project type introduces. They do not assert that a particular scope is permitted or suitable for your address.
Compare planning footprints
See common ADU sizes before choosing a design.
These model pages are planning references only. They are not a statement that a particular size is allowed or buildable at a San Francisco address.
California directory
Explore more city guides.
The next useful action
Put your address at the center of the conversation.
The online review is preliminary and is not a permit decision, survey, engineering opinion, construction document, final price, or guaranteed schedule.