Garage Conversion in San Francisco, CA (2026): Cost, Permits & Rules

A garage conversion is usually the lowest-cost path to an ADU in San Francisco — $120,000-$250,000, versus $200,000-$450,000 for a new detached build — because the shell already exists.

Garage Conversion Cost in San Francisco

Converting an existing garage in San Francisco runs $120,000-$250,000. That's well under the $200,000-$450,000 typical cost of a ground-up detached ADU, because you're reusing the foundation, walls, and roof. The biggest variables are whether the slab and framing are sound, what utility/electrical upgrades are needed, and your finish level. Permit fees add Replace the guessed range with SF's own published figures. DBI's own estimate: 'City fees range from 6-9% of construction costs' (and architects/engineers about 10%; at least $125,000 in material and labor for a new unit). PLANNING development application fee (Fee Schedule eff. 8/29/2025, rev. 6/15/2026) — New Construction: $3,502 flat under $100k; $3,504 base + 3.855% of cost above $100,000 in the $100k-499,999 band; $19,226 + 1.230% above $500,000. Alteration/Change of Use (garage or interior conversion): $504 under $10k; $516 + 5.274% above $10,000; $3,838 + 3.524% above $50,000; $5,638 + 3.855% above $100,000. Neighborhood notification $121 + $4.25/envelope; permit-revision back check $366. DBI building permit fees are TWO separate charges under SF Building Code Table 1A-A (amended Ord. 112-26, eff. 7/12/2026) — Plan Review: $1,671 + $15.60 per $1,000 over $50,000 ($50k-200k band), $4,011 + $13.31 per $1,000 over $200,000 ($200k-500k band); Permit Issuance: $677 + $4.83 per $1,000 ($50k-200k), $1,402 + $4.21 per $1,000 ($200k-500k). Table 1A-A note 1 states these exclude Public Works, Planning, Fire, Public Health and plumbing/electrical/mechanical permit fees. Add SFUSD school facility fees (calculated by DBI staff), SFPUC and Public Works right-of-way permits. OUR WORKED EXAMPLE (label as our calculation, not a published number): a $300,000 detached ADU = Planning $11,214 + DBI plan review $5,342 + DBI issuance $1,823, roughly $18,400 before trade permits and school fees — about 6% of construction cost, consistent with DBI's 6-9%. FEE WAIVER: building permit fees are waived for permits granting legal status to dwelling units built without permits, for activities prior to 1/1/2020 (Board Ord. 150571).. A converted unit rents for about $2,200-$3,200/mo (1BR) in San Francisco.

The San Francisco Garage Conversion Permit Process

A garage-to-ADU conversion in San Francisco needs building permits even if the exterior is unchanged. Approval process: TRUE ONLY OF THE STATE PROGRAM — must be split. STATE PROGRAM: ministerial; no CEQA; no Planning Code Sec. 311 neighborhood notification; no discretionary review; no subjective design review except historic-resource standards for ADUs under Gov. Code 66314; appeals prohibited under AB 1114 for permits filed on or after 1/1/2024; eligible for a free virtual Permit Review Roundtable with DBI, Planning, Public Works, SF Fire and SFPUC in one meeting. LOCAL PROGRAM: requires (a) a Notice of Addition of ADU plus declaration posted in the building and mailed/delivered to every unit including unauthorized units at least 15 CALENDAR DAYS before applying; (b) a declaration filed with the Rent Board under penalty of perjury regarding severance of housing services, which tenants may contest by petition within 30 calendar days; (c) a Project Application (PRJ) to Planning for In-House Review and a Planning Approval Letter BEFORE DBI will accept the building permit; (d) possible Historic Resource Review; (e) Zoning Administrator waivers under PC 207.1(g)/307(l); (f) a recorded Regulatory Agreement / Costa-Hawkins agreement where waivers are granted on a lot with Rental Units. BOTH: an ADU Screening Form must be filed with the permit application, on which the applicant elects State/Hybrid or Local and signs a Rent Ordinance affidavit. ELIGIBILITY BAR (Local only): no ADU where there was an owner move-in eviction within 5 years or another no-fault eviction within 10 years. The review timeline is 60 days from a COMPLETE application under Gov. Code 66317 — but SF requires every ADU applicant to sign an 'Application Processing Time Tolling Declaration Form' electing either to TOLL (pause) the 60-day clock while revising plans, or to hold the City to it. If the applicant declines tolling, DBI may DENY the application if code compliance cannot be established within 60 days, and revised plans must be resubmitted at least 10 business days before the period ends. Most applicants therefore toll and the real elapsed time exceeds 60 days. Add the Local-Program pre-clock: 15 calendar days of posted notice before filing, a Rent Board declaration with a 30-day tenant petition window (Rent Board targets transmitting a determination within 90 calendar days of a petition), then Planning In-House Review and a Planning Approval Letter — all before the building permit is filed. SF states State-Program full permits 'generally has a shorter review and issuance timeline than the Local program.', with plan check: Expedited plan check available. Pre-approved plans: MISLEADING AS WRITTEN — rewrite. DBI runs a Pre-approved ADU Plans program, but it is a program for BUILDING DESIGNERS to submit designs for pre-approval, not a homeowner catalogue. Verified terms: a $2,408 flat fee per plan submitted for pre-approval (a widely repeated $1,519 figure is stale); plans 'should be designed for 25 ft lots'; pre-approval 'is only valid during the current code cycle'; pre-approved plans CANNOT be used in slope protection areas, landslide and liquefaction zones, Maher Zones or flood zones; and site-specific plan check is still required (Planning Code compliance, soils report and site survey, fire separation distance, foundation design, SFUSD fees, tree removal, drainage). Submissions go to dbi.preapprequests@sfgov.org and DBI schedules a Permit Review Roundtable. Do NOT claim it 'saves 2-3 months on design' — nothing on the city's pages supports a time saving. I found NO published catalogue of pre-approved plans; SF Planning's ADU page, Planning Director Bulletin No. 3 and the Local ADU Program Chart do not mention the program at all..

Confirm eligibility — ADUs are allowed in MORE GENEROUS than our list. ADUs are allowed on ANY lot in a zoning district that allows residential use — including mixed-use and commercial districts, not just the RH/RM/RTO family. PC 207.1(b) applies the Local Program to 'all lots located within the City and County of San Francisco in areas that allow residential use'. One SF-specific exclusion worth stating: PC 207.1(c)(12) bars an ADU in a Neighborhood Commercial District or the Chinatown Community Business or Visitor Retail Districts if it would eliminate or reduce ground-story retail space, unless it is a Designated Child Care Unit..
Prepare conversion plans — layout, egress windows, insulation, ventilation, smoke/CO detectors, plus a kitchen and bathroom.
Submit for plan check — Expedited plan check available.
Pull permits and build — fees run Replace the guessed range with SF's own published figures. DBI's own estimate: 'City fees range from 6-9% of construction costs' (and architects/engineers about 10%; at least $125,000 in material and labor for a new unit). PLANNING development application fee (Fee Schedule eff. 8/29/2025, rev. 6/15/2026) — New Construction: $3,502 flat under $100k; $3,504 base + 3.855% of cost above $100,000 in the $100k-499,999 band; $19,226 + 1.230% above $500,000. Alteration/Change of Use (garage or interior conversion): $504 under $10k; $516 + 5.274% above $10,000; $3,838 + 3.524% above $50,000; $5,638 + 3.855% above $100,000. Neighborhood notification $121 + $4.25/envelope; permit-revision back check $366. DBI building permit fees are TWO separate charges under SF Building Code Table 1A-A (amended Ord. 112-26, eff. 7/12/2026) — Plan Review: $1,671 + $15.60 per $1,000 over $50,000 ($50k-200k band), $4,011 + $13.31 per $1,000 over $200,000 ($200k-500k band); Permit Issuance: $677 + $4.83 per $1,000 ($50k-200k), $1,402 + $4.21 per $1,000 ($200k-500k). Table 1A-A note 1 states these exclude Public Works, Planning, Fire, Public Health and plumbing/electrical/mechanical permit fees. Add SFUSD school facility fees (calculated by DBI staff), SFPUC and Public Works right-of-way permits. OUR WORKED EXAMPLE (label as our calculation, not a published number): a $300,000 detached ADU = Planning $11,214 + DBI plan review $5,342 + DBI issuance $1,823, roughly $18,400 before trade permits and school fees — about 6% of construction cost, consistent with DBI's 6-9%. FEE WAIVER: building permit fees are waived for permits granting legal status to dwelling units built without permits, for activities prior to 1/1/2020 (Board Ord. 150571).; then framing, electrical, plumbing, and final inspection.

No Replacement Parking Required

No. California law (AB 68 / Gov Code §66314) prohibits cities from requiring replacement parking when you convert or demolish a garage to build an ADU — so you do not need to add a parking space anywhere on the lot. Owner-occupancy: Correct for ADUs — neither PC 207.1 nor PC 207.2 imposes owner occupancy, matching Gov. Code 66315. Add the JADU exception SF actually applies: if a JADU SHARES sanitation facilities with the main residence, the owner must record a deed restriction that includes an owner-occupancy requirement in either the JADU or the primary home. A JADU with its own bathroom carries no owner-occupancy requirement.

The JADU Option for an Attached Garage

If your garage is attached to the house, you can convert it into a junior ADU (JADU) — capped at 500 sq ft of interior livable space — correct, adopts the state definition. Add the SF-specific caveat: a JADU exists ONLY in the State Program (single-family buildings). The Local Program offers no JADU. A JADU may be combined with a Detached ADU and a Converted ADU. and built within the existing walls. JADUs are cheaper and faster to permit than a full ADU, though they may share sanitation with the main home. A full ADU gives you more size and a separate unit; a JADU is the budget route.

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San Francisco Garage Conversion FAQ

How much does a garage conversion cost in San Francisco?

A garage conversion in San Francisco typically costs $120,000-$250,000 — well below the $200,000-$450,000 cost of a new detached ADU, because the foundation, walls, and roof already exist. Budget separately for permit fees (Replace the guessed range with SF's own published figures. DBI's own estimate: 'City fees range from 6-9% of construction costs' (and architects/engineers about 10%; at least $125,000 in material and labor for a new unit). PLANNING development application fee (Fee Schedule eff. 8/29/2025, rev. 6/15/2026) — New Construction: $3,502 flat under $100k; $3,504 base + 3.855% of cost above $100,000 in the $100k-499,999 band; $19,226 + 1.230% above $500,000. Alteration/Change of Use (garage or interior conversion): $504 under $10k; $516 + 5.274% above $10,000; $3,838 + 3.524% above $50,000; $5,638 + 3.855% above $100,000. Neighborhood notification $121 + $4.25/envelope; permit-revision back check $366. DBI building permit fees are TWO separate charges under SF Building Code Table 1A-A (amended Ord. 112-26, eff. 7/12/2026) — Plan Review: $1,671 + $15.60 per $1,000 over $50,000 ($50k-200k band), $4,011 + $13.31 per $1,000 over $200,000 ($200k-500k band); Permit Issuance: $677 + $4.83 per $1,000 ($50k-200k), $1,402 + $4.21 per $1,000 ($200k-500k). Table 1A-A note 1 states these exclude Public Works, Planning, Fire, Public Health and plumbing/electrical/mechanical permit fees. Add SFUSD school facility fees (calculated by DBI staff), SFPUC and Public Works right-of-way permits. OUR WORKED EXAMPLE (label as our calculation, not a published number): a $300,000 detached ADU = Planning $11,214 + DBI plan review $5,342 + DBI issuance $1,823, roughly $18,400 before trade permits and school fees — about 6% of construction cost, consistent with DBI's 6-9%. FEE WAIVER: building permit fees are waived for permits granting legal status to dwelling units built without permits, for activities prior to 1/1/2020 (Board Ord. 150571).) and any electrical or utility upgrades the conversion triggers.

Do I need a permit to convert a garage in San Francisco?

Yes. Converting a garage to a living unit in San Francisco requires building permits even if the exterior stays the same — the work has to meet code for insulation, egress, ventilation, electrical, and a kitchen/bathroom. The ADU permit timeline is 60 days from a COMPLETE application under Gov. Code 66317 — but SF requires every ADU applicant to sign an 'Application Processing Time Tolling Declaration Form' electing either to TOLL (pause) the 60-day clock while revising plans, or to hold the City to it. If the applicant declines tolling, DBI may DENY the application if code compliance cannot be established within 60 days, and revised plans must be resubmitted at least 10 business days before the period ends. Most applicants therefore toll and the real elapsed time exceeds 60 days. Add the Local-Program pre-clock: 15 calendar days of posted notice before filing, a Rent Board declaration with a 30-day tenant petition window (Rent Board targets transmitting a determination within 90 calendar days of a petition), then Planning In-House Review and a Planning Approval Letter — all before the building permit is filed. SF states State-Program full permits 'generally has a shorter review and issuance timeline than the Local program.', and the process is: TRUE ONLY OF THE STATE PROGRAM — must be split. STATE PROGRAM: ministerial; no CEQA; no Planning Code Sec. 311 neighborhood notification; no discretionary review; no subjective design review except historic-resource standards for ADUs under Gov. Code 66314; appeals prohibited under AB 1114 for permits filed on or after 1/1/2024; eligible for a free virtual Permit Review Roundtable with DBI, Planning, Public Works, SF Fire and SFPUC in one meeting. LOCAL PROGRAM: requires (a) a Notice of Addition of ADU plus declaration posted in the building and mailed/delivered to every unit including unauthorized units at least 15 CALENDAR DAYS before applying; (b) a declaration filed with the Rent Board under penalty of perjury regarding severance of housing services, which tenants may contest by petition within 30 calendar days; (c) a Project Application (PRJ) to Planning for In-House Review and a Planning Approval Letter BEFORE DBI will accept the building permit; (d) possible Historic Resource Review; (e) Zoning Administrator waivers under PC 207.1(g)/307(l); (f) a recorded Regulatory Agreement / Costa-Hawkins agreement where waivers are granted on a lot with Rental Units. BOTH: an ADU Screening Form must be filed with the permit application, on which the applicant elects State/Hybrid or Local and signs a Rent Ordinance affidavit. ELIGIBILITY BAR (Local only): no ADU where there was an owner move-in eviction within 5 years or another no-fault eviction within 10 years.

Do I have to replace the parking if I convert my garage in San Francisco?

How long does a garage conversion take in San Francisco?

Plan on 60 days from a COMPLETE application under Gov. Code 66317 — but SF requires every ADU applicant to sign an 'Application Processing Time Tolling Declaration Form' electing either to TOLL (pause) the 60-day clock while revising plans, or to hold the City to it. If the applicant declines tolling, DBI may DENY the application if code compliance cannot be established within 60 days, and revised plans must be resubmitted at least 10 business days before the period ends. Most applicants therefore toll and the real elapsed time exceeds 60 days. Add the Local-Program pre-clock: 15 calendar days of posted notice before filing, a Rent Board declaration with a 30-day tenant petition window (Rent Board targets transmitting a determination within 90 calendar days of a petition), then Planning In-House Review and a Planning Approval Letter — all before the building permit is filed. SF states State-Program full permits 'generally has a shorter review and issuance timeline than the Local program.' for permit review (Expedited plan check available for plan check), then construction. A garage conversion is usually faster to build than a ground-up ADU because the structure already exists.

Can I convert an attached garage into a JADU in San Francisco?

If the garage is attached to the house, yes — a junior ADU (JADU), capped at 500 sq ft of interior livable space — correct, adopts the state definition. Add the SF-specific caveat: a JADU exists ONLY in the State Program (single-family buildings). The Local Program offers no JADU. A JADU may be combined with a Detached ADU and a Converted ADU., can be carved out of the existing footprint, which includes an attached garage. JADUs are cheaper but may share sanitation with the main home.

Compare your options: see the full San Francisco ADU rules, estimate your build with the San Francisco ADU cost calculator, or read the general garage conversion guide.

Garage Conversion in San Francisco, CA: Cost, Permits & Rules (2026)