Bolthole Index

Los Angeles County, California

Zoning, building permits and land rules in Hidden Hills, California

The City of Hidden Hills, California requires a building permit for new construction, additions and remodels, issued by the city's own Building and Safety/Planning department rather than Los Angeles County1. Hidden Hills adopts its own zoning, with RA-S and R-1 zones2. Who handles septic permits inside city limits is unconfirmed, so ask the city before you rely on a septic system.

At a glance

Building permit
Required for new construction, additions and remodels; issued by the city1
Zoning
City zoning with RA-S and R-1 zones2
Minimum lot (RA-S)
1 acre, 150 feet average width3
Minimum lot (R-1)
20,000 sq ft, 95 feet average width4
Front setback
50 feet in RA-S, 35 feet in R-156
Septic
Not confirmed inside city limits; county Public Health handles it in unincorporated areas7
RV living
No city rule confirmed; state guidance limits RVs to RV and mobilehome parks unless a local ordinance allows otherwise8
Building code
City adopts state codes with local amendments9

Who to call

Building permits

City of Hidden Hills, Building and Safety/Planning Department

Plan check, building permits and inspections inside Hidden Hills, plus planning and subdivision review

(818) 888-9281

[email protected]

6165 Spring Valley Road, Hidden Hills, CA 91302

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 Hidden Hills means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Hidden Hills, California?

Yes. New construction, additions and remodels inside Hidden Hills city limits need a building permit from the city's Building and Safety/Planning department1. The department reviews plans, issues the permit and inspects the work through final inspection, and permits are issued only after plans are complete and corrected as required1. The city prepares updated building and fire codes with local amendments, so check the city's amendments as well as the state code9. Inspection requests must be made 24 hours in advance10.

The rules on this page are the city's. Los Angeles County's unincorporated-area permit and zoning rules do not apply inside Hidden Hills; land outside city limits follows the Los Angeles County page.

Who issues building permits in Hidden Hills, and how do you reach them?

The City of Hidden Hills Building and Safety/Planning department issues building permits and plan checks, and the work is provided under contract by Transtech1. Applications start at the city's online permit center: create an account, submit the application and PDF plans, and pay plan check and permit fees by card, with convenience fees1112. Counter and phone hours are 9 a.m. to 11 a.m., Monday through Friday12. Call (818) 888-9281 or email [email protected]12. We could not confirm the city's current permit fee amounts, so ask the department for a fee estimate12.

Does Hidden Hills have zoning, and what are the lot size and setback rules?

Hidden Hills has its own zoning, with RA-S and R-1 zones2. Lot rules differ by zone, so find your parcel's district first.

  • RA-S: a minimum lot area of 1 acre and a minimum average width of 150 feet3; front setback of at least 50 feet from the road easement line5; building coverage up to 25 percent of net lot area13.
  • R-1: a minimum lot area of 20,000 square feet and a minimum average width of 95 feet4; front setback of at least 35 feet6; building coverage up to 30 percent of the lot, counting roof overhangs14.

In both zones, the roof ridge cannot exceed 30 feet at the most generous distance from the front line, and the height cap is 34 feet15. R-1 uses the same envelope and cap as RA-S16.

How do septic permits work inside Hidden Hills?

We could not confirm who permits septic or other onsite wastewater systems inside Hidden Hills city limits, or whether new homes must connect to a sewer. Los Angeles County Public Health's Environmental Health division reviews septic plans in unincorporated areas and contracted cities7, but we did not confirm that Hidden Hills falls under that program. Before you plan on a septic system, ask the city's Building and Safety/Planning department and the county's Onsite Wastewater Treatment Program which agency applies to your parcel. Los Angeles County's soils rate poorly for conventional drain fields: only about 6.6% of soils are rated not limited, so expect a site evaluation17. That figure is countywide, not specific to Hidden Hills.

Can you live in an RV or tiny home in Hidden Hills?

We could not confirm a Hidden Hills rule on living in an RV, camping, or occupying a tiny home on a lot, so do not assume any of these are allowed. California's state guidance says RVs are not intended for occupancy as a permanent dwelling and generally may be occupied only in mobilehome parks or special occupancy parks, unless a local ordinance allows otherwise8. Call the city's Building and Safety/Planning department at (818) 888-9281 before parking or living in a camper or placing a small dwelling on your lot12.

Building a home in Hidden Hills: the steps, in order

  1. Confirm your parcel's zone, RA-S or R-1, and its lot size, setbacks, coverage and height limits with the city2.
  2. If you are dividing land, expect Planning review under the Subdivision Map Act18.
  3. Check whether the parcel sits in a special flood hazard area; new construction there must meet the city's flood hazard standards19.
  4. Ask which agency handles septic or sewer for your lot, as described above.
  5. Create an account at the city's permit center, then submit the application and PDF plans11.
  6. Pay plan check and permit fees, then correct plans as the reviewer requires; permits are issued only after that1.
  7. Request inspections 24 hours ahead through final inspection10.

What stays with Los Angeles County, and what to check before you buy in Hidden Hills

Hidden Hills sits in Los Angeles County, but the county's Title 22 zoning applies only to unincorporated land, not to a city's own territory20. For land outside city limits, use the Los Angeles County page. Before you buy inside Hidden Hills, confirm the zone and its lot standards, flood hazard status19, and the septic or sewer arrangement. We could not confirm the city's rules on well permits, driveways or short-term rentals, so ask the city. Los Angeles County's typical home value is about $888,42621, and its effective property tax rate is about 0.7%22.

Watch-outs

  • We could not confirm who permits septic systems inside Hidden Hills city limits; ask the city's Building and Safety/Planning department before you plan a septic system; Los Angeles County Public Health handles septic permits in unincorporated areas7.
  • Hidden Hills sets its own height envelope and cap, so a plan that fits Los Angeles County's rules can still fail city review15.
  • Lots of record created on or before December 3, 1963 that fall below the RA-S minimum are not nonconforming solely for that reason3.
  • Counter and phone hours at the building department are only 9 a.m. to 11 a.m. on weekdays, so plan calls for the morning12.

Sources

  1. Hidden Hills Building and Safety/Planning (Hidden Hills), quoted and re-checked
  2. Hidden Hills Code 5-2E-2 R-1 Zone Lot Size and Coverage (Hidden Hills), quoted and re-checked
  3. Hidden Hills Code 5-2C-2 RA-S Zone Lot Size and Coverage (Hidden Hills), quoted and re-checked
  4. Hidden Hills Code 5-2E-2 R-1 Zone Lot Size and Coverage (Hidden Hills), quoted and re-checked
  5. Hidden Hills Code 5-2C-4 RA-S Zone Yards and Setbacks (Hidden Hills), quoted and re-checked
  6. Hidden Hills Code 5-2E-4 R-1 Zone Yards and Setbacks (Hidden Hills), quoted and re-checked
  7. Local Agency Management Program (LAMP), quoted and re-checked
  8. hcd.ca.gov (California statewide rule), quoted and re-checked
  9. Hidden Hills Building and Safety/Planning (Hidden Hills), quoted and re-checked
  10. Hidden Hills Building and Safety/Planning (Hidden Hills), quoted and re-checked
  11. Hidden Hills Building and Safety/Planning (Hidden Hills), quoted and re-checked
  12. City of Hidden Hills, Building and Safety/Planning Department (hiddenhills.gov)
  13. Hidden Hills Code 5-2C-2 RA-S Zone Lot Size and Coverage (Hidden Hills), quoted and re-checked
  14. Hidden Hills Code 5-2E-2 R-1 Zone Lot Size and Coverage (Hidden Hills), quoted and re-checked
  15. Hidden Hills Code 5-2C-3 RA-S Zone Building Height (Hidden Hills), quoted and re-checked
  16. Hidden Hills Code 5-2E-3 R-1 Zone Building Height (Hidden Hills), quoted and re-checked
  17. 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
  18. Hidden Hills Building and Safety/Planning (Hidden Hills), quoted and re-checked
  19. Hidden Hills Code 5-9-5 Provisions for Flood Hazard Reduction (Hidden Hills), quoted and re-checked
  20. Los Angeles County Code Title 22: Planning and Zoning, quoted and re-checked
  21. Typical home value (Zillow): Bolthole Index county data
  22. Effective property tax rate: Bolthole Index county data

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.

Answers from the rulebook for Hidden Hills

Hidden Hills’s own rules

  • Building permitRequired

    New construction, additions and remodels inside Hidden Hills city

    • Permits are issued only after plans are complete and corrected as required.
    • Services are provided under contract by Transtech.
    “the department provides plan check, permit issuance, and inspection services for new construction, additions and remodels”
  • Building code adoptedAdopted

    Construction inside Hidden Hills city

    • The city prepares updated building and fire codes every three years as required by the state, with local amendments.
    “the building department prepares, for adoption by the council, updated building and fire codes every three years as required by the state of california. local amendments are also included with this code update.”
  • InspectionsRequired

    Permitted construction inside Hidden Hills city

    • Inspection requests must be made 24 hours in advance.
    “inspections are performed during the construction process through final inspection.”
  • Local zoningPresent

    Land inside Hidden Hills city limits

    • Zoning is in Title 5, Chapter 2 of the city code, with RA-S and R-1 zones.
    “article e. - r-1 zone 5-2e-1: - permitted uses. the following uses are permitted in the r-1 zone:”
  • Minimum lot sizeSpecified

    RA-S Zone inside Hidden Hills city

    • Excludes road, multiple driveway and ingress/egress easement portions.
    • Lots of record on or before December 3, 1963 below the minimum are not nonconforming solely for that reason.

    minimum lot area: >= 1 acre · minimum average lot width: >= 150 feet

    “d. lot width: every lot or parcel shall have a minimum average width of not less than 150 feet.”
    One more reviewed finding on this topic
  • SetbacksSpecified

    RA-S Zone inside Hidden Hills city

    • Side: not less than 15 feet from the easement line or 25 feet from the closest side lot line; 25 feet from a street easement edge when abutting.
    • Rear yard not less than 50 feet, with setback area of 25 feet from rear lot line or 15 feet from easement line, whichever is greatest.
    • Minor structures, projections and porches are allowed in setbacks under stated limits.

    front yard setback: >= 50 feet (measured from the road easement line) · rear yard: >= 50 feet

    “a. front yard setback: every lot or parcel in the ra-s zone shall have a front yard setback of not less than 50 feet measured from the road easement line to the closest supporting member of the structure.”
    One more reviewed finding on this topic
    • Specified — R-1 Zone inside Hidden Hills city
      “a. front yard setback: every lot or parcel in the r-1 zone shall have a front yard setback of not less than 35 feet, measured from the road easement line to the closest supporting member of the structure.”
  • Lot coverageSpecified

    R-1 Zone inside Hidden Hills city

    • Area beneath roof overhangs is included in the calculation.

    maximum building coverage: <= 30 percent of lot area

    “c. maximum coverage: all buildings and roofed structures, including accessory buildings, shall not cover more than 30 percent of the area of the lot. the area beneath roof overhangs shall be included in the calculation of building coverage.”
    One more reviewed finding on this topic
  • Building heightSpecified

    RA-S Zone inside Hidden Hills city

    • Roof ridge 26 ft / cap 30 ft if ridge is less than 65 ft from front property line; 28 ft / 32 ft if 65 to 75 ft; 30 ft / 34 ft if more than 75 ft.
    • Second story floor area not more than 50 percent of first story footprint.

    maximum roof ridge height (ridge over 75 ft from front line): <= 30 feet (lower limits closer to front line) · building height cap (ridge over 75 ft from front line): <= 34 feet

    “the maximum height of the roof ridge shall not exceed 30 feet. in addition, the building height cap shall not exceed 34 feet.”
    One more reviewed finding on this topic
    • Specified — R-1 Zone inside Hidden Hills city
      “a. maximum height envelope and cap: the building height envelope and cap shall not exceed the building height envelope and cap allowed in an ra-s zone.”
  • Subdividing landRegulated (with conditions)

    Land divisions inside Hidden Hills city

    • Administered through the Planning department under the Subdivision Map Act.
    “planning also carries out the requirements of the california environmental quality act (ceqa) and the subdivision map act.”
  • Building in a floodplainRequired

    New construction and substantial improvements in special flood hazard areas inside Hidden Hills city

    • Lowest floor elevated to or above base flood elevation in most zones; Zone AO uses depth number or two feet above highest adjacent grade.
    • Elevation certified by a registered professional engineer or surveyor.
    • Manufactured homes must meet anchoring and elevation standards.
    “1. standards of construction. in all areas of special flood hazards the following standards are required:”
  • Permit processPublished (with conditions)

    Building permits inside Hidden Hills city

    • Create an account at the permit center, submit the application and PDF plans, pay plan check/permit fees by card (convenience fees apply).
    • Counter and phone hours 9-11 a.m. Mon-Fri.
    “plan checks and permits can be applied for online at the hidden hills permit center.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Hidden Hills or Los Angeles County directly.

  • Owner-builder exemption — Owner-builders inside Hidden Hills city
  • Certificate of occupancy — Occupancy of new buildings inside Hidden Hills city
  • Minimum dwelling size — Dwellings inside Hidden Hills city
  • Living in an RV — RV occupancy inside Hidden Hills city
  • Camping on your land — Camping inside Hidden Hills city
12 more unanswered
  • Tiny homes
  • Manufactured homes
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Driveway access
  • Short-term rentals
  • Permit fees

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.

Unanswered questions are usually a sign that Hidden Hills publishes no rule on the point, not that none exists. Los Angeles County’s page lists the county offices to call.

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