Imperial County, CA Building Permits, Zoning & Septic Rules

Unincorporated Imperial County, California requires a building permit for new construction, issued by Planning & Development Services, and by state law virtually all construction including minor modifications requires permits of one type or another¹. Zoning approval is folded into that same permit process under the county's Land Use Code². Septic systems (onsite wastewater treatment systems, or OWTS) are permitted separately by the county's Environmental Health Division, whose review is required before Planning & Development Services will approve a building permit on a lot without public sewer³.

At a glance

Building permit: Required countywide; issued by Planning & Development Services¹
Zoning: Yes — reviewed as part of the building permit process under the county Land Use Code²
Septic permits: Imperial County Public Health, Environmental Health Division (OWTS/Land Use program)³
Owner-builder exemption: Yes, under state law, if you build for your own use and don't intend the home for sale⁴
Well permits: Issued by the County Planning and Development Department⁵
Permit processing time: At least 2 weeks minimum, longer with corrections or added agency review⁶
RV/tiny home/manufactured home living: Not settled by a general rule — depends on classification and county approval; not confirmed at the county level⁷

Who to call

Building permits

Imperial County Planning & Development Services

Building, electrical, mechanical, plumbing, grading and demolition permits, zoning approval, and mobile/manufactured home permitting for unincorporated Imperial County

442-265-1736

801 Main St, El Centro, CA 92243

Septic permits

Imperial County Public Health Department, Environmental Health Division

Review and permitting of onsite wastewater treatment system (OWTS/septic) design plans, construction inspection, and septic-related review of building permit applications on lots without public sewer

(442) 265-1888

[email protected]

1221 W. State St., Suite B, El Centro, CA 92243

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 Imperial County, California?

Yes. Building permits are required to authorize new construction, alterations or additions to a building or structure, and by state law virtually all construction including minor modifications requires permits of one type or another — building, electrical, mechanical, plumbing, grading, demolition and more⁶. This matches California's statewide rule: no building or structure may be erected, constructed, enlarged, altered, repaired, moved, improved, removed, converted or demolished unless a separate permit has first been obtained from the building official⁸. In Imperial County, Planning & Development Services is that building official, and permits take a minimum of 2 weeks to process, with additional time for other department approvals or plan-check corrections⁶. California's Business & Professions Code lets an owner build or improve a structure on their own property without a contractor's license, so long as it isn't intended for sale — Imperial County's own permit checklist still requires a completed contractor or owner/builder verification form either way⁴⁶.

Who is the Imperial County building department, and how do you reach them?

Imperial County Planning & Development Services, at 801 Main St in El Centro, issues building, zoning, grading and mobile-home permits for the unincorporated county⁶. A minimum submittal needs a signed permit application, a complete site plan, two copies of plans/details, a property owner acknowledgment form, and a contractor's workers'-compensation or owner-builder form, plus the applicable fee⁶. Watch for a near-term change: the department will soon transition to Civic Access, a new online permitting platform, and expects to begin shifting to the new software during the first two weeks of June — confirm current submittal steps with the department before you apply⁶. Public Works, not Planning & Development Services, issues the separate encroachment or driveway permit you'll need if your access crosses county right-of-way⁶.

Does Imperial County have zoning?

Yes — zoning approval is required as part of the building permit process, and unincorporated Imperial County is zoned under the county's Land Use Code (Title 9)². California law gives counties broad authority to regulate building and structure location, height, bulk, lot coverage, intensity of use, parking and setbacks through zoning ordinances in unincorporated territory⁹. We could not confirm the county's specific numeric setback, minimum lot size, or building-height rules from an official Imperial County ordinance page in this research pass — those depend on your parcel's zoning district, so confirm them directly with Planning & Development Services before you buy or design a project².

How do septic permits work in Imperial County?

Septic systems in Imperial County go through the Public Health Department's Environmental Health Division, not the building department directly³. The Land Use program protects the environment and public health through a review process of proposed land use in Imperial County — it consists of the review of on site wastewater treatment system (septic system) design plans and inspects the construction of on site wastewater treatment system (OWTS)s to prevent threats to public health¹⁰. That review isn't optional for a building permit: we also review applications for building permits on lots served by OWTSs, and Planning & Development Services' own checklist requires a percolation test for the septic tank, leach field and reserve leach field if the lot isn't on public sewer¹⁰⁶. Soils are a moderate constraint countywide: USDA data rates only 11% of Imperial County's soils as free of severe limits for a conventional septic drain field, so budget for a site evaluation before you assume a standard system will work¹¹. Statewide, California's OWTS Policy is implemented by local agencies like Imperial County's Environmental Health Division under a Regional Water Board-approved Local Agency Management Program¹².

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

We could not confirm an Imperial County-specific rule on RV, tiny-home or manufactured-home residential occupancy on private property in this research pass — treat this as a question for Planning & Development Services before you buy or move a unit in². California's statewide default is restrictive for RVs: RVs are not intended for occupancy as a permanent dwelling, and unless a local ordinance allows otherwise, RVs generally may be occupied only in mobilehome parks or special occupancy parks⁷. A tiny home is treated the same way structurally — to be occupied, it must comply with the standards of, and be approved as, one of several defined structure types (manufactured home, California Residential/Building Code home, factory-built housing, RV, park trailer or camping cabin), and a unit that fits none of those categories is a noncomplying structure whose occupancy is illegal¹³. Manufactured homes have a clearer path: Imperial County Planning & Development Services is the state's lead agency for mobile home park administration and oversees the construction, use, maintenance and occupancy of mobile home parks, mobile home lots, permanent buildings and accessory structures⁶.

What are the steps to build a home in Imperial County, in order?

Confirm your parcel's zoning district and any setback or lot-coverage rules with Planning & Development Services before you buy².
If your lot has no public sewer, get your septic design and site evaluation started with the Environmental Health Division early — building permit approval depends on it¹⁰.
Assemble a complete building permit submittal: signed application, site plan, two copies of plans, property owner acknowledgment, and owner-builder or contractor's compensation forms⁶.
If your access crosses county right-of-way, apply separately to Public Works for an encroachment or driveway permit⁶.
Submit to Planning & Development Services for building, electrical, mechanical and plumbing permit review; expect a minimum of 2 weeks for initial processing⁶.
Complete any required well permit through the County Planning and Development Department if you're not on a public water system⁵.
Track the department's move to its new Civic Access online permitting platform, expected to begin the first two weeks of June, in case your application timeline crosses that transition⁶.

What should you check before you buy land in Imperial County?

Confirm your parcel's zoning district and access to public sewer or water with Planning & Development Services, since both drive your permit path and septic requirements². Budget for a real septic site evaluation: only 11% of county soils are rated free of severe limits for a conventional drain field¹¹. This is a hot, dry desert county — average annual precipitation is just 3.2 inches, and the county is projected to see 128.4 days a year at or above 100°F by mid-century, so cooling costs and water planning matter more here than almost anywhere else in this guide's coverage¹⁴¹⁵. A large share of the county, 69%, is federal land, which shrinks the buildable private-land footprint and can affect access and utility easements nearby¹⁶. Typical farmland runs about $11,892 an acre and the median home value is $380,919, while the median property tax bill is $2,348 a year at an effective rate of 0.8%¹⁷¹⁸¹⁹²⁰.

Watch-outs

Imperial County Planning & Development Services will soon transition to a new online permitting platform, Civic Access, with the shift expected to begin the first two weeks of June — confirm current application steps before you submit⁶.
We could not confirm Imperial County's specific numeric setback, minimum lot size, building height, or agricultural-exemption rules, nor a county-specific answer on RV or tiny-home residential occupancy, from an official ordinance page in this research pass; verify all of these directly with Planning & Development Services before you design or buy².

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 Imperial County scores

Seclusion48100% ev.

Self-Sufficiency1396% ev.

Admin Boringness41100% ev.

Durability31100% ev.

Property Autonomy56100% ev.

Carry Cost53100% 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 →

$381kTypical home

0.8%Property tax

$11,892Land / acre

3.2"Annual rain

28.6% of yrsSevere drought

128.4 / yr (+25.6)Mid-century 100°F days

129.7 daysMid-century dry spell

0.64" (+2.8%)Mid-century 1-day rain

1.08×Wildfire change factor

100%Forward climate coverage

$1,241Home insurance / yr

3.5% / yrInsurance growth

1.4%Nonrenewal rate

county median (2+ published ZIPs)Insurance basis

1,050,348People within 2 hr

46,085Radius comparison (15 mi)

42.9People / sq mi

69%Federal land

78.7%Land at 15% slope or less

11%Septic soil without severe limits

258,341 acWorkable land screen

0.1%Wooded land

16.1 tonsBiomass / forest ac

74.3°FAvg temp

Answers from the rulebook for Imperial County

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

Imperial County rules

Well permitRequired
New water-well construction, reconstruction of existing wells, and destruction of abandoned wells in Imperial County.
- The official County Public Health Department page assigns permitting to the County Planning and Development Department.
- The cited source does not provide the application procedure, fee, inspection requirement, or exemptions.
“Permitting of new water well construction, reconstruction of existing wells, and destruction of abandoned wells within Imperial County is regulated by the County Planning and Development Department.”
Water Programs ↗Re-checked Sep 24, 2026
Subdividing landRegulated (with conditions)
Subdivision-related parcel configuration and lot-merger processes administered by Imperial County Planning & Development Services in unincorporated Imperial County.
- The County’s Subdivision Ordinance is Title 9, Division 8, Chapter 8 for owner-requested lot mergers.
- Parcels must be contiguous and not separated or affected by certain easements or rights-of-way for the described merger process.
- The Department determines application completeness within 30 days after submittal.
- The Planning Director or Planning Commission conducts a public hearing and decides based on required findings, including conformance with state law and County ordinance, access, easements, and no creation of new lots.
- County-initiated lot mergers are addressed separately under Title 9, Division 8, Chapter 9 and require notice to the property owner.
application completeness determination: 30 days (after submittal)
“Imperial County’s Subdivision Ordinance (Title 9, Division 8, Chapter 8) establishes the County’s process for lot mergers initiated by the record property owner”
“Lot Mergers”: What They Are, Why They Happen, and How the Process Works ↗Re-checked Sep 24, 2026
County-wide zoningPresent
Zoning approval is required as part of the building permit process; Imperial County zones the unincorporated area under its Land Use Code (Title 9).
Imperial County Planning & Development Services - Building Requirements ↗Scouted from the county site, not yet independently re-checked

California rules that apply here

Building permitRequired
Construction projects within the California Department of Health Care Access and Information Office of Statewide Hospital Planning and Development jurisdiction, including health-facility projects requiring HCAI review.
- Written plan approval must be issued before the building-permit application proceeds.
- The application must provide contractor information, Inspector of Record information, and a Testing Inspection and Observation program.
- The TIO program must be field-approved before approval and subsequent issuance of the building permit.
- This claim does not establish the permit rule for projects outside HCAI jurisdiction.
“Once a project receives written plan approval, a Building Permit application is submitted through the e-Services Portal.”
Building Permits & Construction Observation ↗Re-checked Sep 26, 2026
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
- Conditional — Owner-builders constructing or improving structures on their own property, including qualifying single-family residential projects, in Imperial County and elsewhere in California.
  “An owner who builds or improves a structure on his or her property, provided that both of the following conditions are met:”
  California Code, BPC 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
Building code adoptedAdopted (with conditions)
California Building Standards Code, California Code of Regulations, Title 24, including the 2025 California Building Code and related parts, for buildings and structures subject to the state code.
- The 2025 California Building Standards Code applies to buildings and structures with a permit application date on or after January 1, 2026.
- The applicable local building department or enforcing agency determines how the permit application date is established in a specific jurisdiction.
- The code includes multiple parts, including the California Building Code, California Residential Code, Existing Building Code, Electrical Code, Mechanical Code, Plumbing Code, Energy Code, Wildland-Urban Interface Code, Fire Code, and Green Building Standards Code.
effective date: 2026-01-01 · permit application date: >= 2026-01-01
“The 2025 California Building Standards Code (CBSC), California Code of Regulations (CCR), title 24, will become effective on January 1, 2026, as a result of the 2024 Triennial Code Adoption Cycle. [...] The 2025 CBSC applies to all buildings and structures with a permit application date on or after January 1, 2026.”
Approved Building Standards ↗Re-checked Sep 9, 2026
One more reviewed finding on this topic
- Adopted — California statewide building standards, including residential construction subject to Title 24 of the California Code of Regulations.
  “Except as otherwise specifically provided by law, the building standards adopted and submitted by the department for approval [...] shall be adopted by reference”
  California Health and Safety Code Section 17922 ↗Re-checked Sep 26, 2026
InspectionsRequired
Construction projects within HCAI jurisdiction involving California health facilities.
- HCAI field personnel make periodic site visits.
- The Inspector of Record is responsible for continuous inspection of the work.
- The inspections address seismic, fire, life-safety, and other building-code requirements.
“The approved IOR with the required personal knowledge performs only those duties associated with the required continuous inspections”
HCAI Standard Project Process ↗Re-checked Sep 26, 2026
One more reviewed finding on this topic
- Required — California owner-builder projects addressed by the Contractors State License Board guidance.
  “Your project must pass codes and building inspections.”
  Owner-Builder Responsibilities ↗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
One more reviewed finding on this topic
- 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
Driveway accessRequired
Driveways and driveway connections involving proposed encroachments within, under, or over State highway rights of way.
- The requirement applies to proposed activities related to placement of encroachments within, under, or over State highway rights of way.
- Applications are submitted to the appropriate District Encroachment Permits Office having jurisdictional authority over the site.
- Local or other agency requirements may also apply outside State highway rights of way.
“An encroachment permit must be obtained for all proposed activities related to the placement of encroachments within, under, or over the State highway rights of way.”
Encroachment Permits | Caltrans ↗Re-checked Sep 26, 2026
Permit processPublished (with conditions)
Construction, alteration, repair, movement, improvement, removal, conversion, or demolition of a building or structure in California.
- A separate permit for each building or structure must be obtained from the building official before the work.
- Code requirements vary by city and county; the applicable local building department must be consulted.
“no building or structure may be erected, constructed, enlarged, altered, repaired, moved, improved, removed, converted or demolished unless a separate permit [...] has first been obtained”
Do I need a building permit for my project? ↗Re-checked Sep 9, 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.

Minimum lot size — Minimum lot-size requirements for residential development in unincorporated Imperial County.
Lot coverage — Maximum lot-coverage requirements for development in unincorporated Imperial County.
Building height — Building-height requirements for development in unincorporated Imperial County.
Agricultural exemption — Agricultural building, land-use, or construction-permit exemptions in unincorporated Imperial County.
Building in a floodplain — Development in flood-hazard areas of unincorporated Imperial County.

1 more unanswered

Short-term rentals

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 Imperial County, California

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

Imperial County scores 30/100 on the Bolthole Index, a weak county profile. Watch-outs: weak self-sufficiency basics: only 3.2″ of rain a year, in severe drought 28.6% of years and elevated current hazard exposure.

Do you need a building permit in Imperial County, California?

Imperial County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Imperial County Public Health Department - Division of Environmental Health. 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 Imperial County?

Living in an RV on your own land in Imperial 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 Imperial County, California?

Land in Imperial County runs about $11,892 per acre, based on the latest county data.

What is the water situation in Imperial County?

Imperial County gets about 3.2" of rain a year, with severe drought in roughly 28.6% of years.

How remote is Imperial County?

A typical private-land location has about 46,085 people within 15 miles and 7,849,911 within 100 miles. These radius catchments are the published fallback where road routing is unavailable.

Building permits, zoning and septic rules in unincorporated Imperial County, California

At a glance

Who to call

Do you need a building permit in Imperial County, California?

Who is the Imperial County building department, and how do you reach them?

Does Imperial County have zoning?

How do septic permits work in Imperial County?

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

What are the steps to build a home in Imperial County, in order?

What should you check before you buy land in Imperial County?

Watch-outs

Sources

Imperial County in California

How Imperial County scores

Find land. Bring the promising ones back.

Parcel due diligence

Answers from the rulebook for Imperial County

Imperial County rules

California rules that apply here

Still unanswered

Living off-grid in Imperial County, California

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

Do you need a building permit in Imperial County, California?

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

How much does land cost in Imperial County, California?

What is the water situation in Imperial County?

How remote is Imperial County?

How Imperial compares in California