Bolthole Index

San Diego County, California

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

41Index Score / 100
#34 of 58 in California

Unincorporated San Diego County, California requires building permits for most construction, although limited exemptions depend on a structure's size and location1. County zoning applies outside incorporated cities, which administer their own zoning rules2. On land without public sewer, an approved onsite wastewater system may provide sanitation, subject to county permits and review3.

At a glance

Building permit
Required for residential and commercial structures, with limited exemptions1
Zoning
County zoning applies in unincorporated areas; cities use their own rules4
Septic permits
Handled by the San Diego County Department of Environmental Health and Quality5
RV living
Permanent RV and Park Model Trailer habitation on a private lot is prohibited; temporary placement needs county approval67
Tiny homes on wheels
Permanent habitation is possible for a qualifying, permitted THOW8
Manufactured homes
Allowed on qualifying private lots for eligible homes built after September 1971, with a building permit and final occupancy approval9
Setbacks
Parcel-specific under the applicable setback designator and schedule10
Wells
A county permit is required to install or modify a well11

Who to call

Building permits

San Diego County PDS Building Services Division

Building permits, plan review and inspections for unincorporated San Diego County

(858) 694-3900

Online permits →

Planning & zoning

San Diego County Planning & Development Services

Zoning administration and land-use questions for unincorporated San Diego County

(858) 694-3900

Septic permits

DEHQ Land and Water Quality Division, Onsite Wastewater Systems

Onsite wastewater system permits, design review and inspections

(858) 565-5173

lwqdduty@sdcounty.ca.gov

5500 Overland Avenue, Suite 110, San Diego, CA

Contact details are copied from each office’s official page and were checked against it on October 16, 2026.

Off-grid gear

Going off-grid in San Diego County means bringing your own water and power. The kit we’d start with:

These are affiliate links — we may earn a commission, at no cost to you. As an Amazon Associate, Bolthole Index earns from qualifying purchases.

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

Yes, for most residential and commercial construction in unincorporated San Diego County. The Building Services Division issues the permits, while only structures meeting specific size and location requirements qualify for exemptions1. The county has adopted the 2024 International Building Code and 2025 California Building Code, with county amendments taking precedence for unincorporated areas12. Permitted work is inspected as construction proceeds, and a county inspector must approve each successive part13. The completed, signed permit card serves as the Certificate of Occupancy, so retain it after final approval14. California's owner-builder exemption concerns contractor licensing, not the county's permit and inspection requirements15. The county's rules apply to unincorporated land. San Marcos issues its own building permits16, and septic permits inside the county's cities still come from the county health office, as in Del Mar17.

Who is the San Diego County building department, and how do you reach it?

San Diego County Planning & Development Services' Building Services Division handles building permits, plan review and inspections for unincorporated property18. Applicants can use the county's online services to apply for simple building permits, check permit status, schedule inspections and pay fees18. The county assigns each project a Permit Record ID, and every listed condition must be satisfied before permit issuance; those conditions can include fire-district approval, flood control, septic review and driveway review19. The county publishes separate plan-review and permit fees by project type, with valuation used when a project is not specifically listed; every permit can also involve other applicable charges20. Call the county information line shown above when the project is not eligible for a simple online permit or when an exemption is uncertain18.

Does San Diego County have zoning?

Yes. The published County Zoning Ordinance requires land and buildings in unincorporated San Diego County to follow the regulations for the parcel's zone; incorporated cities administer their own zoning21. San Marcos, La Mesa, National City and Del Mar each set zoning inside their own limits22232425. Use the county's zoning tools or GIS and the parcel APN to identify the exact zone and development designators before designing a house2627. Minimum lot area is parcel-specific and may be stated in square feet or acres, while the coverage designator limits how much of the building site may be covered; when both a fraction and square-foot cap appear, the stricter limit controls2728. Setbacks and height are also designator-specific, with possible additional street and fire-code setbacks1029. We could not confirm a countywide minimum dwelling size, so ask Planning & Development Services about the parcel's zone and proposed dwelling type30.

How do septic permits work in San Diego County?

The San Diego County Department of Environmental Health and Quality regulates and permits onsite wastewater systems in unincorporated areas and in municipalities that formally delegate that authority31. A permit is required before installing, repairing, modifying, connecting to or destroying an onsite wastewater system, and the application must document a suitable site, potable water and a building-permit application32. DEHQ inspects installations before backfilling and finalizes the permit only after confirming the system was installed as approved33. Only 12.3% of county soils lack severe limitations for a conventional drain field, so arrange the site evaluation before fixing a house location or purchase budget34. Where public sewer is unavailable, a building may use an approved onsite wastewater system or other sanitation facility approved by the Director3.

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

Permanent habitation in a recreational vehicle or Park Model Trailer on a private lot is prohibited in unincorporated San Diego County6. A Park Model Trailer cannot go on a foundation or pier system or be affixed to the ground for permanent use7. Temporary placement needs Planning & Development Services approval and covers only temporary occupancy (including while a single-family house is built after the building permit is issued), temporary health care or farm employee housing735. Trailer-coach occupancy generally also needs zoning authorization and a valid installation permit36. A qualifying Tiny Home on Wheels may instead receive a permanent habitation permit on a lot that allows a single-family dwelling, subject to construction, fire-safety, utility, wastewater, siting, registration and zoning conditions8. A certified manufactured home is the other permanent route: it may be occupied on a private lot where zoning allows a detached home, if it was built on or after June 15, 1976 with a California HCD insignia or federal certification, or is an eligible mobile home built between September 15, 1971 and June 14, 19769. It needs a PDS building permit before installation on a foundation and Director approval before occupancy, and Wildland-Urban Interface construction rules apply9.

Building a home in San Diego County: the steps, in order

  1. Confirm that the parcel is unincorporated, then identify its zone, lot-size, coverage, setback and height designators with Planning & Development Services2127281029.
  1. Confirm that the proposed dwelling type is allowed; an ADU needs an existing or planned main house, and a THOW must qualify under the county's permanent-habitation standards378.
  1. Determine whether public sewer connection is required; otherwise obtain DEHQ approval and a permit for an onsite wastewater system3832.
  1. Obtain a separate county permit if installing or modifying a well11.
  1. Submit plans to Building Services, review the variable fees and clear every condition attached to the Permit Record ID3919.
  1. Request inspections during construction, pass the final inspection and retain the completed permit card as the Certificate of Occupancy1314.

What should you check before buying land in San Diego County?

Verify legal access and determine whether driveway work enters a public right-of-way or county easement, because improvement plans or driveway review may apply40. If access connects to a state highway, a Caltrans encroachment permit is required41. Determine whether a building must connect to public sewer before budgeting septic; where sewer is unavailable, the sanitation system still needs county approval383. Check septic feasibility early because only 12.3% of county soils lack severe limitations for a conventional drain field34. Agricultural and ranch support structures and new or expanded agricultural uses have a narrow exemption from specified Groundwater Ordinance review tied to Major Use Permits, but the exemption does not override other laws and does not cover feed lots42. If you plan to divide land, county subdivision rules can add access, road, drainage, erosion-control, water and fire-infrastructure requirements43.

Watch-outs

  • Permanent private-lot habitation in an RV or Park Model Trailer is prohibited, and a Park Model cannot be placed on a foundation; temporary use during home construction requires an issued building permit6735.
  • An onsite wastewater permit and installation inspection are required, and only 12.3% of county soils lack severe limits for a conventional drain field323334.
  • San Diego County setbacks and building heights are parcel-specific, and fire-code or street-related setbacks may be more restrictive1029.
  • An owner-builder exemption concerns contractor licensing; the owner-builder must still obtain permits and pass inspections15.

Sources

  1. Building Division Home, quoted and re-checked
  2. Zoning Ordinance, quoted and re-checked
  3. San Diego County Code § 68.310, Public Sewer Availability, quoted and re-checked
  4. Zoning Ordinance, quoted and re-checked
  5. San Diego County Code § 68.301, Purpose and Scope (2026 county census)
  6. Types of Accessory Units, quoted and re-checked
  7. Requirements for Placing a Certified Manufactured Home on a Private Lot, quoted and re-checked
  8. Tiny Home on Wheels Director’s Determination, quoted and re-checked
  9. Requirements for Placing a Certified Manufactured Home on a Private Lot, quoted and re-checked
  10. Zoning Ordinance Summary, quoted and re-checked
  11. Water Well Program, quoted and re-checked
  12. San Diego County Building Codes, Ordinance No. 10982 (N.S.), quoted and re-checked
  13. How to Obtain a Building Permit Summary, quoted and re-checked
  14. How to Obtain a Building Permit Summary, quoted and re-checked
  15. Owner-Builder Overview, quoted and re-checked
  16. San Marcos: San Marcos Code 20.245.050 Manufactured Homes on Residential Lots (San Diego County), quoted and re-checked
  17. Del Mar: Frequently Asked Questions on Septic Systems (San Diego County), quoted and re-checked
  18. San Diego County PDS Building Services Division (sandiegocounty.gov)
  19. Building Division Home, quoted and re-checked
  20. Building Construction Permit Fees (PDS613), quoted and re-checked
  21. Zoning Ordinance, quoted and re-checked
  22. San Marcos: San Marcos Code 20.245.030 Allowable Mobile/Manufactured Home Uses and Permit Requirements (San Diego County), quoted and re-checked
  23. La Mesa: La Mesa Municipal Code 24.05.030 Development standards (San Diego County), quoted and re-checked
  24. National City: National City Code 18.10.050 Interpretation of land use code provisions (San Diego County), quoted and re-checked
  25. Del Mar: R1-5 Development Standards (San Diego County), quoted and re-checked
  26. Zoning Ordinance, quoted and re-checked
  27. Zoning Ordinance Summary, quoted and re-checked
  28. sandiegocounty.gov, quoted and re-checked
  29. sandiegocounty.gov, quoted and re-checked
  30. San Diego County Planning & Development Services (sandiegocounty.gov)
  31. San Diego County Code § 68.301, Purpose and Scope, quoted and re-checked
  32. San Diego County Code § 68.325, Permit Required, quoted and re-checked
  33. Final 2025 Local Agency Management Program for OWTS, quoted and re-checked
  34. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  35. sandiegocounty.gov, quoted and re-checked
  36. Ordinance 8962, San Diego County Code amendments, quoted and re-checked
  37. Accessory Dwelling Units, quoted and re-checked
  38. San Diego County Code § 68.310, Public Sewer Availability, quoted and re-checked
  39. Building Forms and Handouts, quoted and re-checked
  40. Improvement Plan Application User Guide, quoted and re-checked
  41. Encroachment Permits | Caltrans (California statewide rule), quoted and re-checked
  42. San Diego County Groundwater Ordinance, quoted and re-checked
  43. San Diego County Code of Regulatory Ordinances — Subdivision Ordinance, quoted and re-checked

Written October 16, 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.

Found land here? Start a Property Hunt →

Compared with neighboring counties

Like all 6 of its neighbors, San Diego County requires a building permit for a home.

RuleSan Diego CountyRiverside CountyOrange CountyImperial CountyLos Angeles CountySan Bernardino CountyVentura County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredRequired
County zoningYesYesYesYesYesYesYes
Septic permitsCounty Dept. of Env. Health & QualityCounty Dept. of Env. HealthCounty Health Care AgencyCounty Public Health Dept.County Dept. of Public HealthCounty Env. Health ServicesCounty Env. Health Div.

County locator

San Diego County in California

41
County map
San Diego County highlighted among the California counties · colored by Index score

How San Diego County scores

Seclusion22100% ev.
Self-Sufficiency4198% ev.
Admin Boringness54100% ev.
Durability41100% ev.
Property Autonomy56100% ev.
Carry Cost26100% ev.

Evidence strength: 99%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$941kTypical home
0.7%Property tax
$36,053Land / acre
13"Annual rain
27.9% of yrsSevere drought
24.6 / yr (+11.4)Mid-century 100°F days
78.2 daysMid-century dry spell
1.51" (+8.2%)Mid-century 1-day rain
1.11×Wildfire change factor
100%Forward climate coverage
$1,883Home insurance / yr
6.1% / yrInsurance growth
1.38%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
5,134,508People within 2 hr
569,378Radius comparison (15 mi)
776.7People / sq mi
24.8%Federal land
63.9%Land at 15% slope or less
12.3%Soils rated "not limited" for septic (strict USDA rating)
281,407 acWorkable land screen
38.7%Wooded land
19.6 tonsBiomass / forest ac
63.3°FAvg temp

Scout San Diego County

Camp here before you commitBook a few nights nearby on Hipcamp →Already own land here?Earn money hosting campers — get $100 when you become a Hipcamp host →

Some links are affiliate or referral links — we may earn a commission, at no cost to you.

Property hunt

Find land. Bring the promising ones back.

Search live inventory elsewhere, then cost and vet each candidate here. No copied listings, account, or paid data feed.

View your full hunt →
ZillowLand & lotsRealtor.comLand listingsLandSearchRural & vacant land

Each button opens a current land search for San Diego County. Listing sites control their own results and filters.

Analyze a property
Add setup-cost allowances

Use rough quotes or placeholders. Blank fields count as $0.

Working estimate

—land + entered setup costs
Asking $ / acre
—
Setup allowance
—
All-in $ / acre
—

A planning estimate, not a valuation or contractor quote. The USDA benchmark includes farm land and buildings; it is context, not a parcel comp.

Before an offer

Parcel due diligence

0/8 checked

Saved properties and checklist progress stay on this device. Bolthole Index does not receive them.

Cities and towns in San Diego County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Not yet researched: Chula Vista · Oceanside · San Diego · Vista

Answers from the rulebook for San Diego County

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

San Diego County rules

  • Building permitRequired

    Construction, enlargement, alteration, conversion, repair, movement, or demolition of structures in unincorporated San Diego County.

    • Permits must be obtained prior to construction.
    • Work exempt from permits is addressed in Permit Requirement Exceptions form BD 110.
    • Even when a building permit is not required, projects must follow the Zoning Ordinance, Public Health and Safety Codes, and other County, state, or federal regulations.
    • The County states that certain structures meeting specific requirements, including size and location, may be exempt from building permits.
    “A permit is required to construct, enlarge, alter, convert (including change of occupancy, use, or character), repair, move, or demolish a structure. Permits are also required for grading, plumbing, electrical, and mechanical work. Permits must be obtained prior to construction. For a list of work exempt from permit, see Permit Requirement Exceptions (form BD 110).”
  • Building code adoptedAdopted (with conditions)

    Building-code requirements for construction, alteration, moving, demolition, repair, and use of buildings and structures in unincorporated San Diego County.

    • The County adopts the 2024 International Building Code and the 2025 California Building Code portion of the California Building Standards Code, with County modifications, additions, and deletions reasonably necessary because of local climatic, geological, or topographical conditions.
    • State code amendments take precedence over the 2024 IBC; the 2024 IBC applies to code sections not adopted by the State.
    • County amendments take precedence over both the 2024 IBC and 2025 CBSC provisions.
    • The code includes requirements for permits and inspections and applies to new construction and alterations, repairs, or reconstruction except as otherwise provided.
    • The ordinance states that the CBSC becomes effective as to the County 180 days after publication by the California Building Standards Commission.

    adopted model building code: 2024 International Building Code (State-adopted code amendments take precedence) · adopted California code: 2025 California Building Code portion of CBSC (County amendments take precedence) · CBSC local effectiveness: per 180 days after publication by the California Building Standards Commission

    “This chapter adopts as the County Building Code, for the unincorporated area of the County, the 2024 International Building Code (IBC), 2025 California Building Code”
  • InspectionsRequired

    Construction performed under a San Diego County building permit in the unincorporated county area.

    • In most areas of the County, at least one working day of notice is required for inspections.
    • The County may not be able to provide next-day inspections in some remote areas.
    • A building inspector must approve each part of subsequent construction.
    • An inspection must be requested and construction progress demonstrated every six months for a building permit to remain active.
    • Permits have a maximum duration of three years; expired permits may be renewed for a percentage of current fees and may be subject to new regulations in effect at renewal.
    • Changes to approved plans must be submitted, reviewed, and approved before work proceeds; inspections are delayed until the plan-change process is complete.

    inspection notice in most areas: >= 1 working day (Some remote areas may not provide next-day inspections.) · required inspection/progress interval to keep permit active: per 6 months · maximum permit duration: 3 years (Expired permits may be renewed for a percentage of current fees.)

    “A County building inspector must approve each part of the subsequent construction. Once construction begins, an inspection must be requested – and construction progress demonstrated – every six months for a building permit to remain active. Permits have a maximum duration of three years.”
  • Certificate of occupancyRequired

    Buildings covered by the San Diego County building-permit process in unincorporated San Diego County.

    • All required inspections, including final inspection, must be passed to obtain a Certificate of Occupancy.
    • The County does not provide a separate document signifying the Certificate of Occupancy.
    • The completed, signed-off permit card is the Certificate of Occupancy and should be retained.
    “All required inspections (including final inspection) must be passed to obtain a Certificate of Occupancy. (See Final Residential Inspection Requirements, form PDS 117) A separate document will not be provided to signify Certificate of Occupancy. The completed, signed-off permit card is the Certificate of Occupancy and should be retained.”
  • County-wide zoningPresent (with conditions)

    Land-use regulation in unincorporated areas of San Diego County.

    • The County Zoning Ordinance applies to areas of San Diego County that are not part of a city.
    • Incorporated municipalities administer their own zoning rules.
    “The Zoning Ordinance sets rules for how land can be used in areas of San Diego County that are not part of a city.”
  • Local zoningVaries (with conditions)

    Countywide aggregate of zoning authority: the County regulates unincorporated areas, while incorporated municipalities within San Diego County regulate land within their municipal boundaries.

    • The County Zoning Ordinance applies only in areas that are not part of a city.
    • The City of San Diego states that all properties within the city have zoning designations under its Land Development Code.
    • Other incorporated municipalities may have their own zoning ordinances and zoning maps.
    “All properties within the City of San Diego have zoning designations reflecting the current designations in the Land Development Code.”
    One more reviewed finding on this topic
    • Varies (with conditions) — Aggregate local zoning across San Diego County, including County zoning for unincorporated areas and separate municipal zoning within incorporated cities.
      “The Zoning Ordinance sets rules for how land can be used in areas of San Diego County that are not part of a city.”
  • Zoning districtsPublished (with conditions)

    County zoning districts and associated zoning regulations in the unincorporated areas of San Diego County.

    • The County Zoning Ordinance applies to unincorporated areas and requires land and buildings to conform to regulations applicable to the zone in which the land is located.
    • The ordinance does not apply to County parks, County facilities, Indian Reservation lands, federally owned or state-owned public lands, and certain specified County solid-waste projects.
    • Incorporated cities administer their own zoning rules.
    “All zones (Residential, Agricultural, Commercial,Industral, etc)”
  • Minimum lot sizeDistrict specific (with conditions)

    Lots in unincorporated San Diego County; the applicable minimum is determined by the parcel's zoning development designator and may be stated in square feet or acres.

    • The County states that actual zoning regulations applied to unincorporated parcels are found through the County GIS and require the parcel APN.
    • A lot-size number indicates required net lot area in square feet unless acres are specified.
    • Village-zone properties may have regulations in applicable Village Zone Development Regulations.
    • Subdivision, General Plan density, special-area, septic, and other applicable regulations may also affect development.

    minimum lot area: parcel-specific zoning designator (number indicates required net lot area in square feet unless acres are specified)

    “Lot Size: Number indicates required net lot area in square feet, unless acres are specified.”
  • SetbacksDistrict specific (with conditions)

    Setbacks for development in unincorporated San Diego County, determined by the parcel's setback designator and applicable setback schedule.

    • The setback letter refers to the Setback Schedule.
    • Special street setbacks may apply under Section 4816.
    • Additional setbacks may apply on streets in the County General Plan Circulation Element.
    • Fire Code setbacks may be more restrictive and must be checked with the local Fire Marshal.
    • For designator V, setbacks are established during planned development, use permit, or site plan review.
    • Setback schedule footnotes include exceptions for lot size, street width, adjoining uses, alleys, open space, and subdivision recording dates.

    setback designator: A through W (designator V is established during planned development, use permit, or site plan review) · front, side, and rear setbacks: schedule values feet (subject to schedule footnotes and potentially more restrictive Fire Code setbacks)

    “setback designator on the Setback Schedule”
  • Lot coverageDistrict specific (with conditions)

    Lot coverage in unincorporated San Diego County, determined by the parcel's coverage designator.

    • A decimal fraction specifies maximum lot coverage as a fraction of the total building site.
    • A whole number specifies maximum coverage in square feet.
    • If both are specified, the more restrictive limit applies.
    • The applicable coverage designator is parcel-specific.

    maximum lot coverage: parcel-specific coverage designator (if both fraction and square-foot limits are specified, the more restrictive applies)

    “Lot Coverage. The maximum area of a building site which may be covered by a building is indicated by either of the following numbers: a. A decimal fraction specifies the maximum lot coverage as a fraction of the total building site. b. A whole number specifies the maximum coverage in square feet. If both are specified, the more restrictive applies.”
  • Building heightDistrict specific (with conditions)

    Building height in unincorporated San Diego County, determined by the parcel's height designator.

    • The height schedule provides designator-specific maximum feet and story limits.
    • Any number of stories is permitted for applicable designators when all building-code and floor-area-ratio limitations are met.
    • Height in excess of 60 feet requires a Major Use Permit.
    • The applicable height designator is parcel-specific.

    maximum height: 15 to 60 feet (designator R allows greater than 60 feet; any height over 60 feet requires a Major Use Permit) · maximum stories: 1 to 4 or code/FAR limited stories (varies by height designator)

    “Height: Letter indicates height designator”
  • Living in an RVLimited

    Use or occupancy of trailer coaches, including recreational vehicles treated as trailer coaches, in unincorporated San Diego County.

    • Use or occupancy must be authorized by the County Zoning Ordinance.
    • A valid, unexpired trailer coach installation permit issued and approved by the Director of Planning and Land Use is generally required.
    • No installation permit is required for temporary trailer use during a trailer roundup when a Department of Environmental Health permit has been issued.
    • The application must include required supplementary information and the nonrefundable application fee specified in County Code Section 56.202.3.
    • The permit may include discretionary conditions, expires on its specified date, and may be revoked or suspended for noncompliance.

    permit validity: valid and unexpired · application fee: specified in Section 56.202.3 (nonrefundable)

    “except when authorized by The Zoning Ordinance of San Diego County and in accordance with a valid unexpired trailer coach installation permit”
    3 more reviewed findings on this topic
    • Prohibited — Permanent habitation of a Park Model Trailer or recreational vehicle on a private lot in unincorporated San Diego County.
      “Park Model trailers are not allowed for permanent use on private lots. [...] RV’s are not approved for permanent habitation.”
    • Temporary only (with conditions) — Temporary occupancy of a Park Model Trailer on a private lot in unincorporated San Diego County during construction of a single-family residence.
      “a Park Model trailer may only be used (with issuance of a Building Permit) [...] during construction of a single-family residence.”
    • Temporary only (with conditions) — Park Model Trailers, identified by the County as a type of recreational vehicle, on private lots in unincorporated San Diego County.
      “A Park Model Trailer shall not be used for permanent habitation”
  • Tiny homesLimited

    Permanent habitation of a Tiny Home on Wheels in unincorporated San Diego County.

    • The THOW must be designed and constructed to ANSI A119.5 standard for Park Models and have a certification sticker before permit issuance from an accredited third-party inspection agency.
    • Exterior walls must meet the stated noncombustible, ignition-resistant, heavy-timber, or log-wall requirements; stucco or cement plaster must be at least 7/8 inch thick, and applicable WUI guidelines apply.
    • Windows, eaves, soffits, fascia, roofing, fire sprinklers, loft egress, carbon-monoxide detectors, and smoke detectors must meet the determination's requirements; the fire-sprinkler requirement has an exception when the unit is used as an ADU and applicable ADU exemptions apply.
    • The THOW must not exceed 430 square feet measured from the inside face of walls and must have at least R-13 insulation in all exterior walls.
    • The THOW must remain licensed and registered with the California Department of Motor Vehicles, cannot move under its own power, and cannot have slide or pop-out features that increase habitable square footage.
    • The THOW must be at least six feet from other structures and parked on a paved pad meeting the specified asphalt or cement thickness requirements, with movement-prevention installations.
    • Required building permits must be issued for connection to electric, water, and sewer utilities; mechanical equipment must be incorporated into the structure rather than placed on the roof.
    • The THOW must be no greater than one story and no higher than 16 feet; a sleeping loft up to 150 square feet is allowed and is not considered a second story.
    • A THOW used as a single-family dwelling must comply with applicable main-building setbacks, building type, density, and other zoning regulations. The policy does not change property zoning or allowed density.
    • A THOW used as an ADU requires no additional parking, and displaced parking caused by its placement need not be replaced; however, it cannot block or remove required parking for the primary residence.
    • A qualifying THOW is eligible for a permit allowing permanent habitation and may be used on a lot that allows a single-family dwelling. Removal requires a demolition permit to remove the dwelling from county records.
    • For OWTS-served property, DEHQ review and approval of an OWTS Layout Report is required; secondary-dwelling OWTS density is generally limited to a combined six bedrooms with a conventional OWTS or ten bedrooms with supplemental treatment, subject to applicable acreage allowances.
    • All dwellings, including THOWs, must have an approved potable water source and wastewater-disposal method. Hauled water, composting toilets, holding tanks, and portable toilets are not approved for new THOW construction.

    maximum floor area: <= 430 square feet (measured from inside face of walls) · maximum height: <= 16 feet (maximum height) · maximum stories: 1 story (sleeping loft up to 150 square feet is not a second story) · minimum separation from other structures: >= 6 feet · minimum exterior-wall insulation: R-13 · maximum sleeping loft: <= 150 square feet (loft is not considered a second story)

    “A THOW meeting the above standards is eligible for a permit that would allow permanent habitation.”
  • Manufactured homesAllowed (with conditions)

    Residential occupancy of eligible manufactured homes (called mobilehomes in the ordinance) on private lots in unincorporated San Diego County where a single detached residential building is permitted.

    • Sections 6502 through 6506 apply to mobilehomes on a private lot wherever a single detached residential building is permitted.
    • The home must have been constructed after September 15, 1971 and have a California Department of Housing and Community Development insignia of approval, or be certified under the National Mobilehome Construction and Safety Standards Act of 1974.
    • The home may not have been altered in violation of applicable codes; it must be occupied only as a residential use; and it must conform to the Zoning Ordinance, Subdivision Ordinance, and Health and Safety Code provisions applicable to residential structures.
    • A mobilehome may be on the same lot as conventionally constructed dwellings subject to those regulations.
    • If attached to a permanent foundation, it must comply with Health and Safety Code section 18551.
    • Exterior walls, roofing, and roof overhangs must meet the listed conventional-dwelling standards, subject to the Director’s stated waiver authority for certain accessory canopy structures or concealed roofs.
    • Before installation on a permanent foundation, the owner or licensed contractor must obtain a building permit from Planning and Development Services and comply with Health and Safety Code section 18551(a).
    • The owner must comply with mobilehome registration-cancellation requirements under Health and Safety Code sections 18551(b) and 18550(b).
    • The Director must determine compliance with applicable requirements and conditions before final approval for occupancy.
    • No modification may be granted from these requirements or from Title 25 California Administrative Code requirements that are not subject to local modification.

    eligibility construction date: after September 15, 1971 · minimum roof pitch: >= 2 inches vertical rise per 12 inches horizontal run (unless waived under Section 6506(b)(8) or (b)(9)) · minimum roof overhang: >= 1 foot (measured from the vertical side of the mobilehome, subject to stated exceptions and waiver authority)

    “An eligible mobilehome shall comply with the following requirements when located on a private lot: 1. Has not been altered in violation of applicable codes. 2. Is occupied only as a residential use.”
    One more reviewed finding on this topic
  • Accessory dwellingsLimited

    Accessory dwelling units and junior accessory dwelling units on residential property in unincorporated San Diego County.

    • The property must be in unincorporated San Diego County, be considered residential, and already have an existing or planned main house or single-family dwelling.
    • An ADU must be attached or detached, provide independent living facilities, and be on the same lot as the main house. A JADU must be completely contained within an existing or proposed house; a JADU with direct interior access may share bathrooms with the main house.
    • All ADUs and JADUs must follow County regulations and require a building permit addressing zoning, building, health, and safety codes.
    • An ADU or JADU can be located on a residentially zoned property with an existing single-family residence; property-specific zoning must be checked through the County property summary report.
    • An attached ADU may be up to 50 percent of the single-family dwelling area, subject to a 1,200-square-foot maximum, with stated exceptions to the 50-percent limit when the main house has more than one bedroom.
    • A detached ADU may not exceed 1,200 square feet, regardless of the size of the single-family dwelling.
    • A JADU may not exceed 500 square feet.
    • The County's ADU impact-fee waiver program went into effect January 9, 2019 and ended January 9, 2024. Qualifying projects started before January 9, 2024 did not pay the plan-check fee, but projects whose permits were not issued by January 9, 2024 must pay fees typically collected at permit issuance.
    • The County adopted an AB 1033 program on March 4, 2026 allowing separate ADU sales in unincorporated communities through a condominium conversion process; the County states that implementation went into effect April 4, 2026, and the guidance does not bypass tentative parcel-map or tentative-map processes.
    • For properties with ADU condominiums, effective September 18, 2026, the County requires a right-of-first-refusal contract, an owner-occupancy affidavit for new buyers, and a defined-period public posting and primary-residence disclosure.

    maximum attached ADU area: <= 1200 square feet (also generally limited to 50 percent of the single-family dwelling area, subject to stated exceptions) · maximum detached ADU area: <= 1200 square feet (size does not depend on single-family dwelling size) · maximum JADU area: <= 500 square feet · AB 1033 implementation effective date: 2026-04-04 (separate sale of ADUs through condominium conversion) · ADU condominium local criteria effective date: 2026-09-18 (right of first refusal, owner-occupancy affidavit, and public-posting requirements)

    “An ADU or JADU can be located on a residentially zoned property that has an existing single-family residence.”
  • Who permits septicCounty

    County regulation and permitting of onsite wastewater treatment systems in unincorporated San Diego County and in municipalities that have formally delegated authority to the County.

    • The County LAMP implements statewide OWTS baseline requirements under a Regional Water Quality Control Board-approved local program.
    • The County chapter also applies within a jurisdiction where authority has been delegated through a specific municipal ordinance, memorandum of understanding, or another appropriate mechanism.
    • The cited chapter does not itself establish County DEHQ authority throughout every incorporated municipality absent such delegation.
    “This chapter is applicable to OWTS in the unincorporated areas of San Diego County”
  • Septic permitRequired

    Installing, constructing, reconstructing, repairing, adding to, modifying, connecting to, or destroying an OWTS or other sanitation facility authorized under the County chapter.

    • A permit issued by the Director is required before the covered work begins.
    • A separate application and permit are required for each installation, modification, or destruction.
    • The application must include a scaled system diagram and sufficient information to demonstrate compliance with the County chapter and LAMP.
    • An OWTS installation permit requires proof of a suitable site evaluation, potable water from a public water purveyor or approved domestic well, and a building-permit application.
    • The property grading must be completed and inspected before an OWTS permit is issued.
    • No permit may issue if site or public-health conditions are unsuitable or would risk contamination or an unsanitary condition.
    • The chapter applies to unincorporated areas and delegated municipal jurisdictions; it does not establish universal County authority in all incorporated cities.
    “No person shall install, construct, reconstruct, repair, add to, modify, connect to, or destroy an OWTS [...] without first obtaining a permit issued by the Director.”
  • Septic inspectionRequired

    Installation inspection and finalization of an OWTS installation permit in the County program.

    • After installation is complete, the permittee must give DEHQ at least 24 hours' advance notice that the system is ready for inspection.
    • Unless DEHQ authorizes otherwise, the OWTS installation may not be backfilled before DEHQ inspects and approves it.
    • The installation permit is finalized only after inspection verifies that the OWTS was installed as approved and permitted and meets all minimum requirements.
    • Corrections require a reinspection request within 10 business days.
    • Local land-use agencies typically require completion of all OWTS installation inspections and DEHQ finalization before issuing an occupancy permit.
    • The LAMP scope is unincorporated areas and jurisdictions with delegated authority.

    advance inspection notice: >= 24 hours (unless otherwise authorized by DEHQ) · reinspection request deadline: <= 10 business days (when installation deficiencies are identified)

    “Unless otherwise authorized by DEHQ, no person shall backfill, or cause another person to backfill, an OWTS installation before DEHQ inspects and approves the work.”
  • Off-grid sanitationAllowed (with conditions)

    Use of an onsite wastewater treatment system or other approved sanitation facility where public sewer is unavailable under the County OWTS chapter.

    • When public sewer is unavailable because the sewer-availability conditions are not satisfied, the building must connect to an approved OWTS or other sanitation facilities approved by the Director.
    • The system is approved only if it received all permits required by the County code when installed or modified.
    • The Director determines the required system after considering area, soil porosity, groundwater level, and population density.
    • The OWTS must be designed to receive and dispose of all sewage and liquid waste from the building served.
    • Improper disposal outside an approved public sewer, approved OWTS, or authorized sanitation facility is unlawful.
    • The cited County chapter applies in unincorporated areas and delegated municipal jurisdictions.
    “shall be connected to an approved OWTS, or other sanitation facilities approved by the Director.”
  • Well permitRequired

    Installation or modification of water wells within San Diego County.

    • DEHQ regulates water-well design, construction, modification, and destruction throughout San Diego County.
    • Well standards identified by the County apply.
    • Well Completion Reports must be submitted to DEHQ within 60 days after completing the work.
    • For permits approved on or after July 1, 2026, failure to submit the completion report within 180 days of completion prevents new permits from being issued to the driller or consultant until overdue reports are received.
    • If a well has not been constructed within the first 120 days after permit approval, the applicant may request a one-year extension.

    well completion report deadline: 60 days after completing work · permit-approval effective date for 180-day enforcement policy: 2026-07-01 · construction extension request window: 120 days after permit approval (applicant may request a one-year extension)

    “The installation or modification of wells within San Diego County requires owners to obtain a permit”
  • Mandatory utility hookupConditional

    Sewer connection requirements for buildings constructed or reconstructed where public sewer is available under the County OWTS chapter.

    • Connection to public sewer is required when the property abuts a public sewer or a public sewer is within 200 feet of the building.
    • The property must be within the sewer district or annexation to the sewer district must be completed.
    • No easement through adjacent property may be necessary to complete the connection.
    • The replacement-OWTS exception applies when connection fees and construction costs exceed twice the total cost of the OWTS repair and the replacement OWTS meets the chapter and LAMP requirements.
    • When public sewer is unavailable because one or more conditions are not satisfied, the building must connect to an approved OWTS or other sanitation facilities approved by the Director.
    • The cited County chapter applies in unincorporated areas and delegated municipal jurisdictions.

    public sewer distance threshold: <= 200 feet (measured from the building) · replacement OWTS cost exception: > 2 times repair cost (connection fees and construction costs must be greater than twice the total OWTS repair cost)

    “shall be connected to a public sewer if:”
  • Agricultural exemptionConditional

    County Groundwater Ordinance requirements for specified Major Use Permits and Major Use Permit modifications involving agricultural and ranch support structures or new or expanded agricultural land uses in San Diego County.

    • The exemption applies only to the specified Major Use Permits or Major Use Permit modifications listed in Section 67.750(b).
    • Agricultural and ranch support structures must be used in the production, storage, or processing of food, fiber, and flowers; examples include roadside stands, barns, sheds, packing houses, and greenhouses.
    • The exception does not apply to feed lots.
    • New or expanded agricultural land uses include changes in commodities produced on the property, operations performed upon those commodities, and development of additional irrigated acreage, unless accompanied by subdivision.
    • The exemption does not supersede or limit any other applicable law or regulation, including the California Environmental Quality Act.
    • Agricultural and ranch support structures do not include commercial exportation of groundwater for resale outside the basin.
    • A proposed subdivision exempt from filing a tentative map or tentative parcel map is not subject to the ordinance unless it also involves a General Plan or Specific Plan adoption or amendment, a zoning reclassification, or a Major Use Permit or modification thereof.
    “The following Major Use Permits or Major Use Permit modifications are exempt from this ordinance: (1) Those involving the construction of agricultural and ranch support structures used in the production, storage, or processing of food, fiber, and flowers, including but not limited to roadside stands, barns, sheds, packing houses, and greenhouses, except that this exception does not apply to feed lots. (2) Those involving new or expanded agricultural land uses, including but not limited to changes in commodities produced on the property, operations performed upon such commodities, and development of additional irrigated acreage on the property unless accompanied by subdivision.”
  • Subdividing landRegulated (with conditions)

    Subdivision of land in unincorporated San Diego County, including agricultural subdivisions within County Agricultural Preserves subject to Land Conservation Contracts.

    • An agricultural subdivision may not be approved with lots smaller than the minimum lot size specified in the Land Conservation Contract, in addition to Government Code section 66474.4 limitations.
    • Access roads must meet specified minor-subdivision access standards.
    • Required improvements include private-road grading and improvement, drainage and erosion-control facilities, and water-supply pipelines, fire hydrants, and connections as required by the Planning Commission or Board.
    • For agricultural subdivisions with parcels of 20 acres or more, all improvement requirements in subsection 81.410(c)(1) apply.
    • The ordinance lists amendments effective through May 18, 2018.

    minimum agricultural-subdivision lot size: minimum lot size specified in Land Conservation Contract (subject also to Government Code section 66474.4)

    “no tentative map for an agricultural subdivision shall be approved if it proposes lots smaller than the minimum lot size specified in the contract.”
  • Driveway accessLimited

    Driveways and driveway approaches associated with development in unincorporated San Diego County, especially work in public rights-of-way or County easements.

    • Improvement plans are generally required for improvements in public rights-of-way, County-dedicated easements, and certain private road easements.
    • Driveway and approach work may be treated as a minor improvement when allowed by County staff.
    • A single-family residence with a building permit may construct a concrete driveway in the public right-of-way without an improvement plan prepared by a licensed civil engineer if it meets County design criteria.
    • Private driveway self-certification is limited to qualifying projects; the County page states that the full requirements are in the Rules handout.
    “The County of San Diego allows for private driveways to be done under the self-certification process. The full list of requirements can be found in the Rules handout.”
  • Permit feesPublished (with conditions)

    Building permits and applications processed by San Diego County Planning & Development Services for projects in the unincorporated areas of San Diego County.

    • The schedule is effective July 10, 2026.
    • Fees must be paid to Planning & Development Services for processing the listed permits and applications.
    • Every permit is different; applicants must review the linked information, handouts, and forms to determine which fees might apply.
    • For a project not specifically listed in the building-construction or street-naming and addressing fee tables, the fee is calculated based on valuation.
    • The published schedule includes separate plan-review and permit-fee columns and contains permit-type-specific fees and per-square-foot charges.

    schedule_effective_date: 2026-07-10 · schedule_revision_date: 2026-07-06 · example_permit_type: Single Family Dwelling/Duplex · example_plan_review_fee: $2,310 + $0.357/sf USD · example_permit_fee: $2,547 + $0.222/sf USD

    “PDS 613 REV.: 07/06/2026 PAGE 1 of 7 (Effective 07/10/2026) The following fees shall be paid to the Planning & Development Services for the processing of the following permits and applications: SCHEDULE OF BUILDING CONSTRUCTION PERMIT FEES PERMIT TYPE FY 26/27 Plan Review Fee Permit Fee Single Family Dwelling/Duplex $2,310 + $0.357/sf $2,547 + $0.222/sf”
    One more reviewed finding on this topic
    • Variable (with conditions) — Building permit fees for residential and commercial structures in unincorporated San Diego County.
      “This section provides information on many of the fees associated with obtaining building permits. Every permit is different, so please review the information linked here and the handouts and forms linked from this page to determine which fees might apply.”
  • Permit processPublished (with conditions)

    Residential and commercial building permit processing by the County Building Services Division in unincorporated San Diego County.

    • The County provides in-person processing at the Permit Center and online services for applying for simple building permits, checking permit status, scheduling inspections, and paying fees.
    • The County assigns a Permit Record ID and requires applicants to meet each project condition before permit issuance.
    • Conditions may include Fire District Approval, Flood Control, Septic Review, and Driveway Review.
    “We will assign your project a Permit Record ID. It will include requirements for your project called Conditions of Approval. You must meet each condition before we issue your permit.”

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”
    3 more reviewed findings on this topic
    • Conditional — Owners performing or contracting for construction, alteration, repair, improvement, or remodeling of property in San Diego County, subject to California contractor-licensing exemptions.
      “An owner-builder is exempt from licensure, but there are limitations. A license is not required if: The owner-builder does the work themselves or through their own employees with wages as their sole compensation and the structure(s) is/are not intended for sale.”
    • 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”
    • 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”
  • 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.”
  • 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.”
    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.”
  • 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.”
    One more reviewed finding on this topic
    • 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”
  • 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:”
  • 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”

Still unanswered

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

  • Short-term rentals — Short-term rental land-use authorization in unincorporated San Diego 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.

Water rights & wells in San Diego County

Whether a new home can legally get its own water here — the sub-state groundwater regime, from California’s water agency.

Adjudicated — rights fixed

Water rights here have been fixed by a court. New supply effectively means acquiring an existing right.

Household wellPermit required — restricted

California requires no STATE permit for a domestic well — wells are permitted by the county — but under SGMA a Groundwater Sustainability Agency can meter or restrict new wells in medium/high-priority and critically overdrafted basins, and Executive Order N-7-22 requires counties in those basins to get GSA verification that a new well is consistent with the Groundwater Sustainability Plan before permitting.

Limit: 2 acre-feet/year de minimis under SGMA (Water Code §10721(e)) — largely exempt from GSA metering/fees

California DWR / State Water Board — SGMA de minimis & EO N-7-22 Action 9 FAQ ↗

Hybrid state (appropriation + riparian). Groundwater rules change and basin boundaries follow the aquifer, not the county line — confirm current well and appropriation rules with the California state water agency before you buy or drill.Groundwater governance as of Jul 2026, cited to each administering agency.

Living off-grid in San Diego County, California

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

San Diego County scores 41/100 on the Bolthole Index, a marginal county profile. Watch-outs: about 569,378 people within 15 miles and higher long-term carry cost.

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

San Diego County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by San Diego County Department of Environmental Health and Quality. 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 Diego County?

Living in an RV on your own land in San Diego County is limited to specific cases: Use or occupancy of trailer coaches, including recreational vehicles treated as trailer coaches, in unincorporated San Diego County. Use or occupancy must be authorized by the County Zoning Ordinance. A valid, unexpired trailer coach installation permit issued and approved by the Director of Planning and Land Use is generally required. A tiny home is limited to specific cases. Confirm with the county before relying on it.

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

Land in San Diego County runs about $36,053 per acre, based on the latest county data.

What is the water situation in San Diego County?

San Diego County gets about 13" of rain a year, with severe drought in roughly 27.9% of years. On water rights, San Diego County lies in the Borrego Springs Subbasin — Critically Overdrafted (Adjudicated) — Stipulated adjudication (2020) with a ~74% pumping reduction to 2040; extractions capped/allocated by a watermaster; new appropriation effectively closed..

How remote is San Diego County?

A typical private-land location has about 569,378 people within 15 miles and 24,360,248 within 100 miles. These radius catchments are the published fallback where road routing is unavailable.

How San Diego compares in California

Compare side-by-side →See all 58 California counties ranked →