San Francisco County, CA Building Permits & Zoning

San Francisco County, California requires a building permit for nearly all construction, administered citywide by the Department of Building Inspection¹². San Francisco is a consolidated city and county with no unincorporated territory, so the same building code and Planning Code zoning apply to every parcel in the county³. There is essentially no septic here: almost every property already connects to the city sewer system, and a private well instead needs a separate permit from Public Health⁴⁵.

At a glance

Building permit: Required for virtually all construction, administered by DBI¹⁶
Zoning: Citywide zoning applies to every parcel; there is no unincorporated area³⁷
Septic: Essentially none in use; nearly all parcels are on the city sewer, and state OWTS rules cover any system outside sewer service⁸⁴
Well permit: Required from SF Public Health's Water Quality Program before drilling or destroying a well⁵
Owner-builder: Available under California's statewide owner-builder exemption; a declaration is required at permit issuance⁹¹⁰
RV living: Not confirmed locally; state law limits RVs to mobilehome or special occupancy parks unless a local ordinance says otherwise¹¹
Tiny home: Not confirmed locally; state law requires approval as one of several defined structure types before occupancy¹²
Driveway / curb cut: A Street Improvement Permit is required from SF Public Works for a new or modified driveway¹³

Who to call

Building permits

San Francisco Department of Building Inspection (DBI)

Building permits, plan review and inspections for all construction in San Francisco County

628-652-3200

[email protected]

49 South Van Ness Avenue, San Francisco, CA 94103

Planning & zoning

San Francisco Planning Department

Zoning determinations, Planning Code approvals and the Permit Information Center for San Francisco County

628-652-7600

49 South Van Ness Avenue, Suite 1400, San Francisco, CA 94103

Well permits

San Francisco Department of Public Health

Environmental health permitting, including Production Well Construction/Destruction permits through its Water Quality Program, for San Francisco County

415-554-2500

1145 Market Street, San Francisco, CA 94103

Roads & driveways

San Francisco Public Works

Street Improvement Permits for new, modified or overwide driveways and curb cuts affecting the San Francisco public right-of-way

628-271-2000

Contact details are copied from each office’s official page and were checked against it on September 24, 2026.

Do you need a building permit in San Francisco, California?

San Francisco County requires a building permit for virtually all construction, alteration, repair, movement or demolition work covered by the San Francisco Building Code¹⁶. If work that needs a permit starts without one, the Department of Building Inspection must complete a special investigation before it can issue a permit for that work⁶. Every permit application filed since January 2026 is reviewed under the 2025 California Codes and the 2025 San Francisco Building Code Amendments, with no grace period for older code editions¹⁴¹⁵. California's statewide owner-builder exemption lets a property owner perform the work personally, or use employees paid wages as their sole compensation, without a contractor's license, though an Owner-Builder Declaration is still required when the permit is issued⁹¹⁰.

Who is the San Francisco building department, and how do you reach them?

The Department of Building Inspection (DBI) approves plans and issues permits for all construction in the City and County of San Francisco, and confirms that buildings comply with building and housing codes¹⁶². DBI's public counter is at 49 South Van Ness Avenue, San Francisco²; reach DBI Customer Service at 628-652-3200 or [email protected] for permit questions². Any construction that needs a permit must stay accessible and exposed for inspection until a building official approves it, and some construction types require continuous inspection by special inspectors¹⁷.

Does San Francisco have zoning?

San Francisco County has zoning, and it applies to every parcel because San Francisco is a consolidated city and county with no unincorporated territory: one Planning Code and one zoning map cover land uses countywide³⁷. Zoning regulations divide San Francisco into zoning districts, and the Planning Code marks each use in a district as Permitted, Conditionally Permitted or Not Permitted¹⁸¹⁹. A project can also need Planning Approval, a Conditional Use Authorization, a variance, environmental review, design review, neighborhood notification or a public hearing depending on the district and the use, so confirm your parcel's zoning district with San Francisco Planning before you assume what you can build¹⁸. California's ADU law lets an owner add an accessory dwelling unit or junior ADU with ministerial approval, with no discretionary review or hearing, once the local permitting agency confirms the application is complete, which it must do in writing within 15 business days of receiving it²⁰.

How do septic and well permits work in San Francisco?

San Francisco County has almost no working septic systems: nearly every parcel already connects to the city's combined sewer system, and the septic rules that do exist are the statewide framework for onsite wastewater treatment systems (OWTS) that fall outside normal sewer service⁸⁴. Under the San Francisco Bay Basin Plan, an onsite system covered by the state's conditional waiver is applied for through a local agency, and any system outside that waiver is regulated directly by the water board⁴. Soils across San Francisco County reinforce why septic is rare here: only 30.6% of the county's soils lack severe limits for a conventional drain field²¹. A private well for irrigation or industrial use instead needs a Production Well Construction/Destruction permit from the San Francisco Department of Public Health's Water Quality Program, which requires a site plan showing a 500-foot radius around the well and a completion bond, contractor's bond, cash deposit or other security of at least $10,000⁵²². We could not confirm an official San Francisco-specific inspection schedule for onsite wastewater systems; ask the Department of Public Health directly before you rely on one²².

Can you live in an RV or tiny home on your land in San Francisco?

We could not confirm a San Francisco ordinance that allows year-round RV occupancy on private land in San Francisco County, so do not assume it is allowed before asking the Department of Building Inspection or Planning directly². California law treats RVs as temporary units: unless a local ordinance says otherwise, an RV may generally be occupied only inside a licensed mobilehome park or special occupancy park, not on an ordinary residential or vacant lot¹¹. The same logic applies to tiny homes: a structure marketed as a tiny home can only be legally occupied once it is approved as one of the defined types the state recognizes, such as a HUD-Code manufactured home, a California Residential or Building Code home, factory-built housing, a recreational vehicle, a park trailer or a camping cabin, and the location has to be approved for that classification¹². We could not confirm an official San Francisco position on tiny-home occupancy beyond code amendments that decline to adopt the state's tiny-house and manufactured-housing appendices, so treat a tiny home on San Francisco land as needing the same permits, plan review and inspections as any other dwelling until DBI confirms otherwise².

Building a home in San Francisco: the steps, in order

Confirm your parcel's zoning district and what it allows with San Francisco Planning before you design anything¹⁹¹⁸.
If you're planning a small subdivision of 10 or fewer residential units, ask Public Works and Planning about the SB 684 streamlined review path early, since it starts with a Public Works application before Planning will process it²³.
File your building permit application with the Department of Building Inspection; anything filed since January 2026 is reviewed under the 2025 California Codes and San Francisco's 2025 code amendments²¹⁴.
If you plan to perform the work yourself, sign the Owner-Builder Declaration at permit issuance under California's owner-builder exemption¹⁰.
If your project needs a new or wider driveway, apply separately to San Francisco Public Works for a Street Improvement Permit; cuts of 30 feet or more need an Overwide Driveway Permit²⁴¹³.
Keep permitted work accessible and exposed for DBI inspection at each stage, and notify DBI when it's ready; some construction types require continuous inspection by a special inspector¹⁷.
If you need a well instead of city water for irrigation or industrial use, apply to the Department of Public Health's Water Quality Program before drilling²²⁵.

What to check before you buy land in San Francisco

San Francisco County is the most urbanized county in the state, with 17,244 people per square mile and a typical home value around $1.4 million, so budget for city land prices even on a small lot²⁵²⁶. About 9.8% of the county is federal land, largely the Presidio and other national park land, which isn't available to build on and can shape what sits next to a parcel you're considering²⁷. Confirm water and sewer service before you buy: San Francisco properties are typically already connected to the city's sewer system, but the county could not confirm an official connection mandate for every private property, so ask the San Francisco Public Utilities Commission directly about your specific parcel⁸. San Francisco sees severe drought in 34.9% of years and gets about 25.5 inches of rain annually, so a property that would depend on any private water source is a bigger risk than the city average suggests²⁸²⁹. Typical property tax in San Francisco County runs about 0.7% of assessed value, or roughly $9,412 a year on a median bill, and a buyer should also budget around $2,396 a year for typical home insurance³⁰³¹³². San Francisco's hills mean terrain varies a lot by neighborhood even though 70.6% of the county's land sits at a gentle 15% slope or less, so check the specific grade of any lot before you plan foundations or a driveway³³.

Watch-outs

San Francisco's building code changed for every permit application filed since January 2026, with no grace period under the prior code cycle; confirm which code edition applies to your specific application with DBI¹⁴.
We could not confirm an official San Francisco rule on RV or tiny-home occupancy on private land, or on off-grid sanitation; ask the Department of Building Inspection or Planning before you assume either is allowed².
The 75% site-coverage limit cited in one San Francisco Planning variance case applied to a single Chinatown Visitor Retail district example, not a countywide rule; confirm your own zoning district's lot-coverage limit with San Francisco Planning rather than assuming one citywide number³⁴¹⁹.

Sources

Written September 24, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

How San Francisco County scores

Seclusion6100% ev.

Self-Sufficiency5191% ev.

Admin Boringness41100% ev.

Durability45100% ev.

Property Autonomy56100% ev.

Carry Cost27100% ev.

Evidence strength: 98%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$1396kTypical home

0.7%Property tax

$48,425Land / acre

25.5"Annual rain

34.9% of yrsSevere drought

0.1 / yr (+0.1)Mid-century 100°F days

91.6 daysMid-century dry spell

1.69" (+5.2%)Mid-century 1-day rain

1.07×Wildfire change factor

100%Forward climate coverage

$2,396Home insurance / yr

2% / yrInsurance growth

0.59%Nonrenewal rate

county median (2+ published ZIPs)Insurance basis

1,771,780People within 30 min

11,846,987People within 2 hr

1,781,515Radius comparison (15 mi)

17,244People / sq mi

9.8%Federal land

70.6%Land at 15% slope or less

30.6%Septic soil without severe limits

5,037 acWorkable land screen

57.3°FAvg temp

Answers from the rulebook for San Francisco County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

San Francisco County rules

Building permitRequired
Construction and other work regulated by the San Francisco Building Code in San Francisco County, including work for which the code requires a permit.
- The requirement applies to work for which a permit is required under the code; the code contains project-specific permit provisions and exceptions.
- If work requiring a permit starts without one, a special investigation is required before a permit may be issued.
- The San Francisco Department of Building Inspection administers the building-code permit process for the consolidated City and County of San Francisco.
“Whenever any work, for which a permit is required under the provisions of this code, has been started without a permit and where no specific additional fees are imposed as penalties as provided in this chapter, a special investigation shall be made before a permit may be issued for such work.”
2025 San Francisco Building Code Amendments ↗Re-checked Sep 24, 2026
Building code adoptedAdopted (with conditions)
Construction subject to the City and County of San Francisco Department of Building Inspection.
- Permit applications filed on or after January 1, 2026 must use the 2025 California Codes and the 2025 San Francisco Code Amendments.
- There is no grace period.
- The Department of Building Inspection approves plans and issues permits for construction in the City.
current code application date: >= 2026-01-01 (Permit applications filed before this date may be governed by the prior applicable code cycle.)
“If you file on or after January 1, 2026, you must use the 2025 California Codes and the 2025 San Francisco Code Amendments. There is no grace period.”
Department of Building Inspection ↗Re-checked Sep 24, 2026
InspectionsRequired
Construction or work for which a permit is required under the San Francisco Building Code in San Francisco County.
- All permitted construction or work must remain accessible and exposed for inspection until approved.
- The permit applicant must keep the work accessible and exposed; the jurisdiction is not liable for removal or replacement costs required to allow inspection.
- The person performing permitted work must notify the building official when the work is ready for inspection and provide access.
- Certain construction types require continuous inspection by special inspectors.
- Required sequential inspections and building-official approval must occur before work is covered or concealed.
“All construction or work for which a permit is required shall be subject to inspection by the building official, and all such construction or work shall remain accessible and exposed for inspection purposes until approved by the building official. In addition, certain types of construction shall have continuous inspection by special inspectors as specified in Section 1701.”
2025 San Francisco Building Code Amendments ↗Re-checked Sep 24, 2026
County-wide zoningPresent (with conditions)
Land uses throughout the consolidated City and County of San Francisco are governed by zoning districts and the San Francisco Planning Code.
- The Planning Code classifies uses as Permitted, Conditionally Permitted, or Not Permitted.
- Project-specific zoning, approvals, fees, environmental review, design review, neighborhood notification, and possible public hearings may apply.
“Zoning regulations govern how land can be used in areas of San Francisco called "zoning districts" (also known as "zones" or "use districts"). Zoning regulations are found in the San Francisco Planning Code, which articulates if a use is either Permitted (P), Conditionally Permitted (C), or Not Permitted (NP).”
Permits | San Francisco Planning ↗Re-checked Sep 24, 2026
Local zoningVaries (with conditions)
Local zoning across San Francisco County, aggregated across San Francisco zoning districts and use districts administered under the San Francisco Planning Code.
- Zoning rules vary by zoning district and use.
- A use may be permitted, conditionally permitted, or not permitted depending on the applicable district.
- Project-specific approvals may include Planning Approval, Conditional Use Authorization, Variance, environmental review, design review, neighborhood notification, and public hearing requirements.
“Zoning regulations govern how land can be used in areas of San Francisco called "zoning districts" (also known as "zones" or "use districts"). Zoning regulations are found in the San Francisco Planning Code, which articulates if a use is either Permitted (P), Conditionally Permitted (C), or Not Permitted (NP).”
Permits | San Francisco Planning ↗Re-checked Sep 24, 2026
Lot coverageDistrict specific (with conditions)
The cited CVR Chinatown Visitor Retail zoning district example at 675 Jackson Street
- At the lowest level occupied by a dwelling, site coverage may not exceed 75%.
- A project exceeding that limit requires a variance; the cited example had 100% coverage and therefore required a variance.
- Other districts may have different lot-coverage rules.
maximum site coverage at lowest dwelling level: <= 75 percent (Variance required for exceedance)
“PLANNING CODE SECTION 134.1 requires that at the lowest level occupied by a dwelling, the site coverage shall be no more than 75%.”
Zoning Variance Hearing ↗Re-checked Sep 24, 2026
Well permitRequired
Construction or destruction of production wells in San Francisco County under the City and County Department of Public Health Water Quality: Production Well Program.
- The application requires owner, consultant, or driller information and construction or destruction specifications.
- A plot plan must show a 500-foot radius around the well or soil boring and identify specified property, disposal, drainage, well, access, structure, utility, and waste-disposal features.
- An SFPUC approval is required if drilling fluids or extracted water will be discharged into the sanitary sewer.
- Completion bonds, contractor bonds, cash deposits, or other adequate security of at least $10,000 must be submitted.
plot-plan radius: 500 feet · minimum completion security: >= 10000 USD (The source allows completion bonds, contractor bonds, cash deposits, or other adequate security.)
“Application for Production Well Construction/Destruction [...] permission is hereby granted to commence the described project.”
Application for Production Well Construction/Destruction ↗Re-checked Sep 24, 2026
Subdividing landRegulated (with conditions)
Subdivision projects and residential developments of 10 or fewer units using San Francisco's SB 684 process
- The process is a streamlined and ministerial review path, not an exemption from subdivision requirements.
- An application must first be submitted to San Francisco Public Works.
- The applicant then references the Public Works application number to complete the San Francisco Planning application.
maximum residential units for cited streamlined path: <= 10 units
“Senate Bill (SB) 684 provides a streamlined and ministerial review path for subdivision projects and the development of 10 or fewer residential units.”
Small Lot Subdivision and Housing Streamlined Approval (SB 684) ↗Re-checked Sep 24, 2026
Driveway accessRequired
Construction of a new or modified driveway, or reconstruction of an existing driveway, affecting the San Francisco public right-of-way.
- A Street Improvement Permit is required for construction of a new or modified driveway or reconstruction of an existing driveway.
- New, relocated, and overwide driveway cuts under 30 feet may be subject to an annual assessment fee under Public Works Code Section 716.
- Once Public Works tentatively approves the permit, the applicant must have it notarized and recorded and must pay associated fees.
- Standard residential curb cuts are 10 feet long by 3 feet wide, including 18-inch wings; longer-than-standard curb cuts require Planning Department approval, and curb cuts 30 feet or longer require an Overwide Driveway Permit from Public Works.
standard residential curb cut length: 10 ft (If longer than 10 feet, Planning Department approval is required for a non-City Standard curb cut.) · standard residential curb cut width: 3 ft (Includes 18-inch wings.) · overwide driveway permit threshold: >= 30 ft (Required from Public Works.)
“A Street Improvement Permit is required for the construction of the new/modified driveway or reconstruction of existing driveways.”
Application for Driveway/Curb Cut ↗Re-checked Sep 24, 2026
Permit processPartial
Building permit approval and inspection processes administered by the San Francisco Department of Building Inspection.
- DBI approves plans and issues permits for construction in the City and County of San Francisco.
- The source states that current codes depend on filing date: applications filed on or after January 1, 2026 must use the 2025 California Codes and 2025 San Francisco Code Amendments.
- The page provides permit tracking and inspection scheduling resources but does not establish every permit type’s complete workflow.
“DBI approves plans and issues permits for all construction in the City. We make sure buildings are safe and comply with building and housing codes.”
Department of Building Inspection ↗Re-checked Sep 24, 2026

California rules that apply here

Owner-builder exemptionAvailable (with conditions)
Exemption from California contractor-licensing chapter for an owner-builder who builds or improves a structure on the owner’s property; this does not itself establish exemption from local building permits, inspections, or other code requirements.
- For work personally performed by the owner or performed by the owner’s employees, none of the improvements may be intended or offered for sale, and employee compensation must be wages as their sole compensation.
- For work directly contracted to licensed trade contractors, the owner must directly contract with licensees duly licensed for the respective trades.
- For single-family residential structures under the licensed-contractor arrangement, no more than four structures may be intended or offered for sale in a calendar year; this limitation does not apply if the owner contracts with a general contractor for construction.
- For a homeowner improving a principal residence or its appurtenances, the work must be performed before sale, the homeowner must have actually resided in the residence for the 12 months before completion, and the homeowner must not have used this exemption on more than two structures more than once during any three-year period.
- A nonprofit corporation may qualify when assisting an owner-builder participating in a mutual self-help housing program.
- Sale or offering for sale within one year after completion creates a rebuttable presumption that the structure was undertaken for sale; sale or offering for sale of five or more structures within one year creates a conclusive presumption.
- This is a contractor-licensing exemption and should not be treated as a building-permit exemption.
single-family structures intended or offered for sale: <= 4 structures per calendar year (Does not apply if the owner contracts with a general contractor for construction.) · prior residence occupancy: >= 12 months before completion (Applies to the principal-residence homeowner exemption.) · owner-builder exemption use: <= 2 structures during any three-year period (The statute states the homeowner has not availed himself or herself of the exemption on more than two structures more than once during any three-year period.) · sale presumption period: 1 year after completion (Sale or offering for sale creates a rebuttable presumption; five or more structures creates a conclusive presumption.) · conclusive-presumption threshold: >= 5 structures within one year after completion (Structures sold or offered for sale by the owner-builder.)
“This chapter does not apply to any of the following: (1) An owner who builds or improves a structure on his or her property”
California Business and Professions Code Section 7044 ↗Re-checked Sep 26, 2026
3 more reviewed findings on this topic
- Available (with conditions) — Owners building or improving structures on their own property, including projects in San Francisco County, subject to California Business and Professions Code section 7044.
  “(a) This chapter does not apply to any of the following: (1) An owner who builds or improves a structure on his or her property, provided that both of the following conditions are met: (A) None of the improvements are intended or offered for sale. (B) The property owner personally performs all of the work or any work not performed by the owner is performed by the owner’s employees with wages as their sole compensation.”
  California Business and Professions Code Section 7044 ↗Re-checked Sep 24, 2026
- Conditional — Owners who build or improve structures on their own property, and homeowners improving their principal residence or appurtenances, subject to Business and Professions Code section 7044.
  “(a) This chapter does not apply to any of the following: (1) An owner who builds or improves a structure on his or her property”
  California Business and Professions Code Section 7044 ↗Re-checked Sep 26, 2026
- Available (with conditions) — California contractor-licensing requirements for an owner who builds or improves a structure on the owner’s property; this is not stated as an exemption from building permits, inspections, or other code requirements.
  “This chapter does not apply to any of the following: (1) An owner who builds or improves a structure on his or her property”
  California Business and Professions Code section 7044 ↗Re-checked Sep 26, 2026
Certificate of occupancyRequired
Completed construction projects within HCAI jurisdiction involving California health facilities.
- The HCAI Compliance Officer issues the project-completion Substantial Compliance or Certificate of Occupancy once required conditions are met.
- The stated examples include delivery of all test reports to the Inspector of Record, clearance of outstanding items, and completion of the Testing, Inspection and Observation Program.
- Once construction is completed, the certificate of occupancy allows the owner to apply to the Department of Health Services for a license to operate the health facility.
“Issues the certificate of occupancy and/or construction final.”
HCAI Standard Project Process ↗Re-checked Sep 26, 2026
Zoning districtsPartial
California city and county zoning codes and the zoning districts established by those local jurisdictions.
- The city or county zoning code implements general-plan policies at the individual-parcel level.
- Local zoning codes identify allowed land uses in the jurisdiction’s zoning districts.
- Since 1971, state law requires city or county zoning codes to be consistent with the jurisdiction’s general plan, except in charter cities.
- The source does not publish a statewide list of parcel-specific zoning districts; the applicable local jurisdiction must be consulted.
“The zoning code presents standards for different land uses and identifies which land uses [...] are allowed in the various zoning districts of the jurisdiction.”
Chrome Plating Amendments Environmental and Regulatory Setting ↗Re-checked Sep 26, 2026
Minimum dwelling sizeSpecified
Efficiency units permitted by a California city, county, or city and county.
- The local jurisdiction must adopt an ordinance permitting the efficiency unit.
- Occupancy is limited to no more than two persons.
- The unit may have partial kitchen or bathroom facilities as specified by the local ordinance.
- All other applicable minimum standards under Health and Safety Code Part 1.5 continue to apply.
minimum floor area: >= 150 square feet · maximum occupancy: <= 2 persons
“Notwithstanding Sections 17922, 17958, and 17958.5, a city, county, or city and county may, by ordinance, permit efficiency units for occupancy by no more than two persons which have a minimum floor area of 150 square feet and which may also have partial kitchen or bathroom facilities, as specified by the ordinance.”
California Health and Safety Code Section 17958.1 ↗Re-checked Sep 9, 2026
SetbacksSpecified
Qualifying SB 9 housing developments in single-family residential zones, including development of up to two primary residential units, subject to the cited statutory eligibility requirements and local ministerial review.
- The parcel must be located in a single-family residential zone.
- The project must involve no more than two residential units.
- Objective standards may be applied only if they do not physically preclude the statutory housing objectives, subject to the stated exceptions.
- No setback may be required for an existing structure or a structure constructed in the same location and to the same dimensions as an existing structure.
- For SB 9 projects, side and rear setbacks may not exceed four feet; a local agency may apply a lesser setback, such as 0–4 feet.
- The local agency cannot apply existing side and rear setbacks applicable in the single-family residential zones.
- The four-foot side and rear setback standards are not subject to modification.
- The fact sheet cites Government Code Sections 65852.21(b)(2)(B) and 66411.7(c)(3).
maximum side setback: <= 4 feet (A local agency may choose to apply a lesser setback, including 0–4 feet.) · maximum rear setback: <= 4 feet (A local agency may choose to apply a lesser setback, including 0–4 feet.)
“SB 9 establishes an across-the-board maximum four-foot side and rear setbacks.”
SB 9 Fact Sheet ↗Re-checked Sep 26, 2026
One more reviewed finding on this topic
- District specific (with conditions) — Building setbacks, side and rear yard requirements, and property line requirements under California's State Housing Law framework.
  “building setback, side and rear yard requirements, and property line requirements are hereby specifically and entirely reserved to the local jurisdictions”
  California Health and Safety Code Section 17922 ↗Re-checked Sep 26, 2026
Living in an RVTemporary only (with conditions)
Occupancy of recreational vehicles as residential units in California.
- RVs are not intended for occupancy as permanent dwellings.
- Unless a local ordinance allows otherwise, RV occupancy generally is limited to mobilehome parks or special occupancy parks governed by the Mobilehome Parks Act or Special Occupancy Parks Act.
- Applicable state or local approval and enforcement requirements depend on the RV's location and classification.
maximum gross area: <= 400 square feet (Measured at maximum horizontal projections; internal living room area must be less than 320 square feet excluding specified built-in equipment and bath/toilet rooms.)
“RVs are not intended for occupancy as a permanent dwelling. [...] Unless otherwise allowed by a local ordinance, RVs generally may be occupied only in mobilehome parks or special occupancy parks”
Information Bulletin 2016-01: Tiny Homes ↗Re-checked Sep 9, 2026
Camping on your landLimited
Camping in units operated by the California Department of Parks and Recreation statewide.
- Camping is confined to areas designated for that purpose.
- Occupancy by the same persons, equipment, or vehicles is generally limited to 30 days in any calendar year in that unit.
- The Department may establish shorter or longer occupancy limits.
- When a shorter seasonal limit applies, the camper must vacate the campsite and may not reregister in the unit until 48 hours have expired, measured from 12:00 noon on the checkout day to 12:00 noon on the second day following.
- A district superintendent may permit one-night camping in a day-use area or portion of one, subject to Department-established fees and vehicle limitations; occupants must vacate by 9:00 a.m. the following morning.
- California State Parks' current reservation policy states that each campground has a consecutive-night limit, requires a 48-hour absence after that limit, and generally has a 30-night annual maximum, subject to individual park policies.
general annual occupancy limit: 30 days per calendar year per unit (The Department may establish shorter or longer limits of occupancy.) · return interval after shorter seasonal limit: 48 hours (Measured from 12:00 noon of the checkout day to 12:00 noon of the second day following.) · one-night camping in day-use area: 1 night (Only if permitted by the district superintendent; occupants must vacate by 9:00 a.m. the following morning.)
“Occupancy by the same persons, equipment, or vehicles of any camping facility is limited to a total of 30 days in any calendar year in that unit.”
California Off-Highway Motor Vehicle Laws 2014 ↗Re-checked Sep 26, 2026
One more reviewed finding on this topic
- Allowed (with conditions) — Temporary camping in California special occupancy parks, including parks containing recreational vehicles, tents, or camping cabins.
  ““Special occupancy park” means a recreational vehicle park, temporary recreational vehicle park, incidental camping area, or tent camp.”
  What is a Mobilehome Park or Special Occupancy Park? ↗Re-checked Sep 26, 2026
Tiny homesAllowed (with conditions)
Occupancy of a structure marketed or described as a tiny home in California.
- The tiny home must comply with applicable standards and be approved as a HUD-Code manufactured home, California Residential or Building Code home, factory-built housing, recreational vehicle, park trailer, or camping cabin.
- The location must be approved for the applicable classification.
- A tiny home that does not fit one of those classifications and does not comply with the California Building Standards Code is a noncomplying structure whose occupancy is illegal.
- Approving and enforcing agencies vary depending on whether the unit is inside or outside a mobilehome or special occupancy park.
park trailer or RV gross area limit: <= 400 square feet (Applicable classification-specific exclusions and standards apply.)
“In order to be occupied, a tiny home must comply with the standards of, and be approved as one of the following types of structures: a HUD-Code manufactured home (MH), California Residential Code or California Building Code home, factory-built housing (FBH), recreational vehicle (RV), park trailer (PT) or camping cabin (CC).”
Information Bulletin 2016-01: Tiny Homes ↗Re-checked Sep 9, 2026
Manufactured homesAllowed (with conditions)
Occupancy of manufactured homes inside or outside mobilehome parks in California.
- The manufactured home must satisfy applicable federal standards and California Manufactured Housing Act and Title 25 requirements.
- Installation and approval for occupancy are governed by the Mobilehome Parks Act.
- HCD or a local enforcement agency with assumed Mobilehome Parks Act authority is responsible for ensuring compliance with statutory construction and maintenance requirements.
- Local agency approvals may be necessary for the project.
minimum width for a new manufactured home: >= 8 body feet (The statutory definition also includes units at least 40 body feet in length.) · minimum erected floor area for a new manufactured home: >= 320 square feet
“MHs may be occupied outside or inside of mobilehome parks and installation and approval for occupancy is governed by the Mobilehome Parks Act (MPA), HSC Sections 18200, et seq., and Title 25, CCR Sections 1000, et seq.”
Information Bulletin 2016-01: Tiny Homes ↗Re-checked Sep 9, 2026
Accessory dwellingsAllowed (with conditions)
ADUs and junior ADUs subject to California State ADU Law.
- Approval is ministerial and without discretionary review or a hearing.
- Development standards must be objective and knowable in advance.
- The local permitting agency must determine application completeness and provide written notice within 15 business days.
- If an application is incomplete, the agency must identify missing items and explain how to complete it.
- Local site, building, health, safety, fire, utility, and other applicable requirements continue to apply.
written completeness determination: <= 15 business days (Measured from the permitting agency's receipt of the application.) · final written determination after appeal: <= 60 business days (Applies after receipt of the written appeal.)
“A permit application for an accessory dwelling unit shall be considered and approved ministerially without discretionary review or a hearing [...] A permitting agency shall determine whether an application to create or serve an accessory dwelling unit is complete and provide written notice of this determination to the applicant not later than 15 business days after the permitting agency received the application.”
Accessory Dwelling Unit Handbook March 2026 ↗Re-checked Sep 9, 2026
Who permits septicMixed (with conditions)
California onsite wastewater treatment systems, including septic systems primarily treating domestic wastewater through subsurface disposal.
- The State Water Resources Control Board establishes the statewide OWTS Policy.
- Local agencies, such as county environmental health departments, issue OWTS permits under the statewide policy.
- Local Agency Management Programs may establish locally tailored siting and design standards.
OWTS Policy effective date: 2013-05-13 (Except for Tier 3, local agencies could continue existing permitting programs for 60 months after the effective date.) · Tier 1 maximum flow: <= 3500 gallons per day (Applies to qualifying new or replacement OWTS where no approved LAMP applies.) · Tier 2 maximum flow: <= 10000 gallons per day (Applies under an approved LAMP.)
“The State Water Resources Control Board [...] adopted the OWTS Policy in June 2012. The OWTS Policy authorizes local agencies [...] to issue OWTS permits.”
Onsite Waste Water Treatment Systems ↗Re-checked Sep 26, 2026
2 more reviewed findings on this topic
- Mixed (with conditions) — Onsite wastewater treatment systems affecting San Francisco County.
  “This assessment shall be included in the application submitted to local agencies [...] these systems will be regulated by the Water Board through other regulatory means.”
  San Francisco Bay Basin Plan Chapter 4 ↗Re-checked Sep 24, 2026
- Mixed (with conditions) — Statewide regulation and management of onsite wastewater treatment systems, commonly known as septic systems.
  “Implementation of the OWTS Policy will be overseen by the State Water Board and the regional water quality control boards”
  Water Quality Control Policy for Siting, Design, Operation and Maintenance of Onsite Wastewater Treatment Systems (OWTS Policy) ↗Re-checked Sep 9, 2026
Septic permitLimited
New, replacement, and corrective-action OWTS in California; existing properly functioning systems may fall under Tier 0 rather than new/replacement permitting requirements.
- Tier 1 applies to qualifying new or replacement OWTS when no Regional Water Board-approved LAMP exists, with a maximum flow of 3,500 gallons per day.
- Tier 2 applies to qualifying new or replacement OWTS under an approved LAMP, with a maximum flow of 10,000 gallons per day.
- Tier 3 applies near impaired surface waters subject to a TMDL, a special LAMP provision, or within 600 feet of a water body listed on OWTS Policy Attachment 2; supplemental treatment may apply.
- Tier 4 applies to systems that are not properly functioning and require corrective action.
- Local agencies issue the permits and local LAMP requirements may differ from Tier 1.
Tier 1 maximum flow: <= 3500 gallons per day (Qualifying new or replacement OWTS without an approved LAMP.) · Tier 2 maximum flow: <= 10000 gallons per day (Qualifying new or replacement OWTS under an approved LAMP.) · Tier 3 water-body setback: <= 600 feet (Applies to a water body listed on OWTS Policy Attachment 2.)
“Tier 1 applies when a Local Agency Management Program (LAMP) has not been approved by the Regional Water Board. Maximum flow rate is 3,500 gpd.”
Onsite Waste Water Treatment Systems ↗Re-checked Sep 26, 2026
One more reviewed finding on this topic
- Required — New and replacement onsite wastewater treatment systems (OWTS), commonly known as septic systems, statewide in California.
  “Every new or replacement septic system requires a permit, either through your local jurisdiction (City or County) OR from the Central Coast Water Board.”
  2023 OWTS Policy ↗Re-checked Sep 26, 2026
Septic inspectionLimited
OWTS in a Tier 3 Advanced Protection Management Program with supplemental treatment components, including systems in specified impaired-water-body areas statewide.
- The requirement applies to OWTS in an Advanced Protection Management Program with supplemental treatment components.
- Ongoing monitoring must follow the OWTS operation and maintenance manual or occur more frequently if required by the local agency or Regional Water Board.
- Where telemetry is not possible, the owner or owner's agent must inspect at least monthly while the system is in use and notify the service provider at least quarterly of observed operating parameters.
- For systems designed to meet disinfection requirements, a service provider must inspect proper operation quarterly while the system is in use unless continuous telemetric monitoring is capable of assessing operation.
- Quarterly effluent sampling and certified-laboratory requirements apply to systems subject to the disinfection provisions.
inspection frequency where telemetry is not possible: per monthly (While the system is in use.) · inspection frequency for disinfection systems: per quarterly (While the system is in use, unless continuous telemetric monitoring is capable of assessing operation.)
“Where telemetry is not possible, the owner or owner’s agent shall inspect the system at least monthly while the system is in use as directed and instructed by a service provider and notify the service provider not less than quarterly of the observed operating parameters of the OWTS. [...] OWTS in an Advanced Protection Management Program designed to meet the disinfection requirements in Section 10.10 shall be inspected for proper operation quarterly while the system is in use by a service provider unless a telemetric monitoring system is capable of continuously assessing the operation of the disinfection system.”
2023 OWTS Policy ↗Re-checked Sep 26, 2026
Mandatory utility hookupSewer (with conditions)
Certain existing OWTS in California Tier 3 impaired-water-body areas that commit to connect to a centralized wastewater collection and treatment system regulated through waste discharge requirements.
- The OWTS must have been constructed and operating, or permitted, on or before the date the nearby water body was added to OWTS Policy Attachment 2.
- The owner must commit by legally binding document to connect to a centralized wastewater collection and treatment system regulated through waste discharge requirements.
- The owner must sign the legally binding document within 48 months after the nearby water body's initial listing on Attachment 2.
- The specified connection date may not extend beyond nine years after the date the nearby water body is added to Attachment 2.
- The rule is an exception to Section 10 requirements for qualifying existing or permitted systems; it is not a general statewide requirement that every property connect to public sewer.
deadline to sign connection commitment: 48 months (Measured from the date the nearby water body is initially listed on Attachment 2.) · maximum time to complete connection: <= 9 years (Measured from the date the nearby water body is added to Attachment 2.)
“The owner must sign the document within forty-eight months of the date that the nearby water body is initially listed on Attachment 2. The specified date for the connection to the centralized community wastewater collection and treatment system shall not extend beyond nine years following the date that the nearby water body is added to Attachment 2.”
2023 OWTS Policy ↗Re-checked Sep 26, 2026
Campground & park staysLimited
Occupancy and use of manufactured homes and mobilehomes in California mobilehome parks and other locations subject to HCD jurisdiction.
- HCD administers titling and registration for manufactured homes and mobilehomes.
- HCD-inspected mobilehome parks are subject to health and safety enforcement where local government has not assumed enforcement.
- Manufactured/mobilehome park regulations address construction, use, maintenance, and occupancy.
- Separate local land-use, building, fire, health, and utility requirements may apply.
“MHs may be occupied outside or inside of mobilehome parks and installation and approval for occupancy is governed by the Mobilehome Parks Act (MPA), HSC Sections 18200, et seq., and Title 25, CCR Sections 1000, et seq.”
Manufactured & Mobilehomes ↗Re-checked Sep 26, 2026
2 more reviewed findings on this topic
- Limited — RV and trailer camping at Silver Strand State Beach Campground in the San Diego Coast District.
  “Camping Stay Limits: Applies to persons, equipment, or vehicles and any combination thereof [...] Maximum stay of 30 days per calendar year [...] Maximum 7 consecutive days during peak season (May 15 – September 15) [...] Maximum 14 consecutive days during non-peak season”
  Silver Strand State Beach Campground Rules and Regulations ↗Re-checked Sep 9, 2026
- Limited — Occupancy and use of recreational vehicles in California special occupancy parks and designated RV sections of mobilehome parks.
  “Unless otherwise allowed by a local ordinance, RVs generally may be occupied only in mobilehome parks or special occupancy parks governed by the Mobilehome Parks Act”
  What is a Mobilehome Park or Special Occupancy Park? ↗Re-checked Sep 26, 2026
county zoning authorityGeneral
California county legislative bodies' authority to adopt zoning ordinances regulating buildings, structures, land uses, lots, yards, open space, lot coverage, intensity of use, parking, loading, and setbacks within county jurisdiction, including unincorporated areas.
- The authority is exercised pursuant to Government Code Chapter 4, Zoning Regulations.
- The statute separately authorizes city legislative bodies; incorporated municipalities may exercise their own zoning authority.
- Government Code Section 65850 also lists authority to regulate signs and billboards, building and structure location, height, bulk, number of stories, and size, lot and open-space size and use, lot coverage, intensity of land use, offstreet parking and loading, and building setback lines.
- The cited section states it was amended by Stats. 2017, Ch. 376, Sec. 1, effective January 1, 2018.
“The legislative body of any county or city may, pursuant to this chapter, adopt ordinances that do any of the following:”
California Government Code Section 65850 ↗Re-checked Sep 21, 2026
county building authorityGeneral
California counties administering and enforcing state building standards through county building departments, including residential construction in unincorporated areas.
- Each county must maintain building standards and state building regulations in the office of the building official responsible for administration and enforcement of state building standards.
- The statewide Title 24 standards apply subject to statutory exceptions and any authorized local amendments or local requirements.
- The cited HCD bulletin concerns the 2019 California Building Standards Code and its July 1, 2021 supplement; later code editions may supersede those particular edition dates.
“These codes shall be maintained in the office of the building official responsible for the administration and enforcement of state building standards”
Information Bulletin 2021-02: 2019 California Building Standards Code Supplement ↗Re-checked Sep 26, 2026

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

Off-grid sanitation — Off-grid sanitation systems in San Francisco County.
Agricultural exemption — Agricultural building or land-use exemptions in San Francisco County

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Living off-grid in San Francisco County, California

Is San Francisco County a good place to live off-grid or homestead?

San Francisco County scores 23/100 on the Bolthole Index, a weak county profile. Watch-outs: little seclusion — roughly 1,771,780 people within a 30-minute drive and higher long-term carry cost.

Do you need a building permit in San Francisco County, California?

San Francisco County generally requires a residential building permit, and it enforces county zoning. Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

Can you live in an RV or tiny home on your land in San Francisco County?

Living in an RV on your own land in San Francisco County is allowed on a temporary basis only: Statewide rule. Occupancy of recreational vehicles as residential units in California. RVs are not intended for occupancy as permanent dwellings. Unless a local ordinance allows otherwise, RV occupancy generally is limited to mobilehome parks or special occupancy parks governed by the Mobilehome Parks Act or Special Occupancy Parks Act. A tiny home is allowed. Confirm with the county before relying on it.

How much does land cost in San Francisco County, California?

Land in San Francisco County runs about $48,425 per acre, based on the latest county data.

What is the water situation in San Francisco County?

San Francisco County gets about 25.5" of rain a year, with severe drought in roughly 34.9% of years.

How remote is San Francisco County?

A representative private-land location has about 1,771,780 people within a 30-minute drive and 11,846,987 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

Building permits, zoning and land rules in San Francisco County, California