Hidden Hills Zoning and ADU Guide for Homeowners

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team.

Hidden Hills is a guard-gated, equestrian-style residential city where the housing element lists R-A-S, R-A-S-2, R-1 and commercial restricted zones, and where the city’s preapproved ADU program allows detached units of 250 to 800 square feet. This guide explains the zoning picture, how the ADU program works, how the community association fits in, and what zoning issues mean when you sell.

Hidden Hills zoning at a glance

Department	Planning, provided under contract by Transtech
City Hall	6165 Spring Valley Road, Hidden Hills, CA 91302; (818) 888-9281
Zones named in the housing element	R-A-S, R-A-S-2, R-1 and CR (Commercial Restricted)
Minimum lot size	One acre in R-A-S and R-A-S-2; 20,000 square feet in R-1
Maximum building coverage	30 percent of the lot in R-A-S, R-A-S-2 and R-1
R-A-S setbacks	Front 50 feet, side 25 feet, rear 50 feet
Preapproved ADUs	Detached, one story, 250 to 800 square feet, up to 16 feet high, new construction only
Other approval	Hidden Hills Community Association Architectural Commission

How Hidden Hills land use works

The city’s adopted 2021-2029 housing element describes Hidden Hills as a community where nearly the entire city lies within a guard-gated single-family residential community.

It says the city preserves its equestrian character through large lots, low maximum coverage, ample setbacks, private covenants, conditions and restrictions, and minimal street improvements, including equestrian trails.

The numbers above come from that document and the city’s planning information, and they are a starting point rather than a substitute for the current zoning code: confirm your parcel’s zone, setbacks and height limits with the city before you plan a project or price a sale.

The housing element also reports a 2020 population of 1,868 in 544 households and lists a regional housing need of 40 units for 2021 through 2029. The Planning Department maintains the General Plan, reviews development and land division projects for consistency with city policy, and carries out environmental review under CEQA and the Subdivision Map Act, according to the city’s building and safety page.

Two approvals: the city and the association

The Hidden Hills Community Association oversees compliance with the community’s CC&Rs. The housing element says new housing or subdivision of property within the association is subject to its architectural standards and requires approval of its Architectural Commission.

The city’s ADU page reflects the same two-step reality, stating that a completed application includes association architectural approval and that the city’s approval clock begins when the completed application is submitted.

If you plan any new structure, such as a guest house, an arena, a barn or an ADU, start with the association’s review and the city’s Permit Center in parallel.

How the ADU program works

The city describes an accessory dwelling unit by reference to state law, as an attached or detached residential dwelling unit on a lot with a primary residence. Hidden Hills offers a preapproved ADU plan process with these limits:

• Detached, single-unit ADUs only.
• New construction, not conversions.
• Minimum size 250 square feet and maximum 800 square feet.
• One story, with a height of up to 16 feet measured from grade to roof ridge.
• Approval of a completed application within 30 days, which includes the association’s architectural committee approval.
• Preapproved plans are described as about 70 to 80 percent complete, so site-specific work remains.

ADUs are permitted in the R-A-S, R-A-S-2, R-1 and CR zones, and the housing element lists city incentives including modified development standards such as setbacks, fast-track plan review and permit processing, and outreach.

Statewide, California’s ADU law sits in Government Code sections 66310 through 66342, and it limits how restrictive local rules can be, so check how it applies to your lot. After approval you still need a building permit through the Permit Center, covered in our Hidden Hills building permits guide.

Planning a project: what to prepare

Gather your parcel number, recorded survey, any prior plans and permit history, and photos of the lot and existing buildings. Ask the city to confirm zoning, setbacks, height and coverage, and ask the association about architectural standards and any application schedule.

For an ADU, compare the preapproved plan catalog with your site, then budget for survey, grading and drainage, utility work, and the site-specific plans the city will require.

Because lots here are large, equestrian features such as barns and arenas may also need approval, and past additions may not have been permitted. Check the record before you start.

Zoning and selling a Hidden Hills house

Zoning problems tend to surface late in a sale: a guest house or barn apartment built without approval, an extra structure that exceeds lot coverage, or an addition that never received association sign-off. California sellers generally disclose known unpermitted work.

Our guide to selling as-is with unpermitted work and the seller closing costs guide explain disclosure and costs. You generally have three paths: legalize or remove the issue before listing, sell on the open market and disclose it, or sell as-is to a cash buyer. Before choosing:

• Confirm your zone and what the city’s code allows on your parcel.
• List every structure and unit on the lot, and whether each was permitted and approved by the association.
• Ask what legalizing each item would require, including plans, fees and review time.
• Compare that cost with a no-repairs cash sale.

How to sell a house in Hidden Hills

1. Confirm your zoning and which structures were approved.
2. Gather permits, plans and any city or association correspondence.
3. Request a no-obligation cash offer for the house as it stands.
4. Choose your closing date.
5. Close with no legalization, repairs or showings required.

Our local pages cover related situations in Hidden Hills, including selling as-is, selling an inherited house and selling during a divorce.

Frequently asked questions

What zones does Hidden Hills have?

The city’s housing element lists R-A-S, R-A-S-2, R-1 and CR (Commercial Restricted) zones, with large minimum lot sizes in the residential zones.

How big can a Hidden Hills ADU be?

The city’s preapproved program covers detached, one-story ADUs of 250 to 800 square feet and up to 16 feet in height, as new construction.

How long does ADU approval take in Hidden Hills?

The city describes a 30-day approval timeline that begins when a completed application, including association architectural approval, is submitted.

Do I need the community association’s approval?

The housing element says new housing within the association is subject to its architectural standards and Architectural Commission approval, and the city’s ADU page includes that approval in a completed application.

What is the maximum building coverage?

The housing element lists a maximum of 30 percent of the lot in the R-A-S, R-A-S-2 and R-1 zones. Confirm current standards with the city.

Can I sell my Hidden Hills house with an unpermitted structure?

Yes. You can disclose it and sell as-is, including to a cash buyer. Our statewide guide explains the disclosure rules.

More guides

• We Buy Houses in Hidden Hills
• We Buy Houses in Los Angeles County
• Los Angeles County Property Tax Guide
• Hidden Hills Building Permits Guide
• Hidden Hills Code Enforcement Guide
• All California Guides

Sources

• City of Hidden Hills: Accessory Dwelling Units
• City of Hidden Hills: Building and Safety/Planning
• City of Hidden Hills: 2021-2029 Housing Element

This guide is general information from public sources, not legal advice. Confirm current rules with the city.