Local zoning · Hidden Hills

Hidden Hills — Landscaping and Screening

Q: If my lot is sloped, can I build stepped retaining walls for screening?

The code allows retaining walls up to 3 feet in many contexts but cautions that multiple stepped walls which appear like one taller wall may not be treated as “minor structures.” Confirm the measuring method and whether stepped walls will cause loss of “minor structure” status with the Planning Director (see the retaining wall language in the yard/minor structure rules). § 5-2C‑4 .

Landscaping and Screening under the Hidden Hills local zoning and planning code, with the controlling citations.

Ask a question free See coverage

Last reviewed: July 2, 2026

Overview

This page summarizes what the Hidden Hills Municipal Code (Title V) actually requires for landscaping, screening, trees, fences and walls — and how those rules are applied across the City's zones. It is focused on the local zoning/planning ordinance language (trees, tree permits, yard/setback allowances for fences and walls, site/architectural review, and the City’s water‑efficient landscaping adoption) and cites the controlling code sections. Where the code delegates review to the Hidden Hills Community Association, I note that as an extra approval step. Verify parcel‑specific interpretations with the City.

Key rules at a glance

Tree protection and a formal tree permit program: § 5-8-5 (tree permit), § 5-8-7 (minor tree permit); replacement ratios and protective measures are required.
Water‑efficient landscape plans: the City adopted the California Model Water Efficient Landscape Ordinance via § 5-10-1 and requires compliance plus any HHCA architectural standards § 5-10-2.
Yard/setback allowances for fences, open fencing, and low retaining walls are stated in the RA‑S / setback rules and “minor structures” rules (see § 5-2C‑4 and related text immediately preceding § 5-2C‑5). Boundary fence heights and lighting rules appear in § 5-2C‑5.
Architectural/site plan review is required before erecting landscaping, walls or fences in commercial settings and for many projects: § 5-2F‑6 (site/architectural review required).

(Note: this page links to the City menu pages for related topics — zoning, development standards, design review, parking, overlays, and ADUs — to help you navigate other rules that commonly intersect with landscaping/screening.)

How the code splits rules by district

Below are the actual Hidden Hills district names and the zoning code sections that control landscaping/screening within them. For each district I summarize the landscaping/screening policy excerpted from the ordinance and the parts of the code you will rely on when planning work.

First internal links (one per concept) appear the first time each topic is mentioned:
- Zoning overview: Hidden Hills Zoning
- Development standards/setbacks: Hidden Hills Development Standards
- Design review: Hidden Hills Design Review
- Parking/screening parking areas: Hidden Hills Parking
- Overlay issues: Hidden Hills Overlay Districts
- ADUs (landscaping interplay): Hidden Hills ADUs
- State building code when relevant: California Building Standards Code

RA‑S (Residential‑Agricultural — RA‑S)

Purpose / where it applies: large‑lot residential/agricultural properties; the Yards and Minor Structures rules govern what landscaping and screening can be placed in setbacks. See the RA‑S yard provisions for exact distances. § 5-2C‑4 (Yards/minor structures text immediately preceding § 5-2C‑5) contains the RA‑S yard and minor structure allowances (open fencing, small retaining walls, minor structures) and projection rules.
Typical permitted screening features:
- Open fencing is allowed in side and rear setbacks as a “minor structure” (the code lists open fencing expressly). See § 5-2C‑4.
- Solid retaining walls up to 3 feet in height are allowed if set back from the property line (the code describes solid walls/retaining walls that are three feet or less and located 15 feet or more from the property line). § 5-2C‑4 / related text.
- Projections (eaves, porches) and mechanical equipment may encroach up to 4 feet into side/rear setbacks but equipment must be “permanently screened with a wood or masonry fence.” See the Projections text tied to Yards/Minor Structures. § 5-2C‑4 F.
Trees: the tree permit rules (Chapter 5‑8) apply citywide; see § 5-8-5 for tree permit criteria and replacement/ protection requirements.

Practical note: RA‑S parcels have large rear/setback dimensions (the code calls out rear yard minima and setback areas); landscaping that functions as screening is permitted in many yard areas but must respect the “minor structure” limits and any required setbacks in § 5-2C‑4.

R‑1 (Single‑Family Residential — R‑1)

Purpose / where it applies: standard single‑family residential neighborhoods. The R‑1 provisions generally adopt RA‑S rules where not otherwise stated: § 5-2E‑5 says that where R‑1 does not specify, RA‑S regulations apply. This means setbacks, minor structure allowances, and many fence rules default to the RA‑S language. § 5-2E‑5.
Key screening/landscaping rules:
- Boundary and boundary fence height limits and style rules (e.g., minimum 3 ft 6 in to maximum 6 ft) are in the “Other Requirements” fence text (see § 5-2C‑5). § 5-2C‑5.C sets boundary fence height limits and location constraints.
- No barbed‑wire fences along bridle trails or as perimeter fences on lots: § 5-2C‑5.A.
- Lighting and other outdoor fixture illumination limits that matter for landscape lighting are in § 5-2C‑5.
Trees: the citywide tree permit chapter (Chapter 5‑8) controls tree removal or severe pruning; if you will remove or severely prune protected trees on R‑1 lots, you must follow § 5-8-5 (tree permit).

Practical note: R‑1 projects that change significant landscape elements often trigger site/architectural review or neighbor notice because of potential impacts; the R‑1 chapter explicitly ties back to RA‑S where R‑1 is silent. § 5-2E‑5.

CR (Commercial Restricted — CR)

Purpose / where it applies: Commercial uses carefully limited to protect the residential character; landscaping and screening rules are stricter to ensure compatibility. See § 5-2F‑1 for permitted uses and § 5-2F‑5 for development standards; § 5-2F‑6 requires architectural and site plan review.
Key landscaping/screening rules:
- Required yards and six‑foot decorative masonry walls where a side or rear yard abuts residentially zoned property: § 5-2F‑5.E.
- All required yard areas must be landscaped; yard areas adjacent to residential property must provide an “effective visual barrier” via landscaping — § 5-2F‑5.F.
- Any building/landscape/wall/fence/structure requires architectural & site plan review before construction: § 5-2F‑6.

Practical note: commercial projects often must supply detailed landscape plans showing screening, material samples, masonry wall details for buffer walls, and parking screening; plan approval is discretionary (design findings in § 5-2F‑6).

Decision‑relevant standards (table)

Requirement / trigger	What the code says (plain English)	Code reference
City tree‑permit program	Tree removal/severe pruning requires a tree permit; Planning Director inspects and may require replacement, protection, and bond; replacement ratio default 4:1, never less than 2:1.	§ 5-8-5
Minor tree permit	Minor tree permits: limits on historic/native oak tree pruning/removal (e.g., ≤2 historic trees in minor permit) and replacement tree specs (48‑inch boxes).	§ 5-8-7
Tree protection during construction	Chain‑link fencing at drip lines, supervision for excavation near driplines, hand‑tools for work within 5 ft of drip line are required conditions.	§ 5-8-5 E (protection plan items)
Water efficient landscape	City adopted the California Model Water Efficient Landscape Ordinance; plans must comply and also meet HHCA standards.	§ 5-10-1, § 5-10-2
Boundary / perimeter fence heights	Boundary fences must be ≥3'6" and ≤6' high; fences in easements may be prohibited; no barbed‑wire on bridle trails/perimeter fences.	§ 5-2C-5.C, § 5-2C-5.A
Open fencing & small walls in setbacks	Open fences allowed in side/rear setbacks; solid retaining walls ≤3' allowed if set back 15'+; “minor structures” limits (6' max in some contexts).	§ 5-2C‑4 (Minor structures / Yard allowances)
Mechanical equipment screening	A/C or mechanical equipment may encroach up to 4 ft into side/rear setbacks only if permanently screened with wood or masonry fence.	§ 5-2C‑4 F
Architectural/site plan review	No building, structure, sign, wall, fence or landscaping shall be erected/altered without Planning Agency architectural & site plan review where required.	§ 5-2F‑6

Checklist (what an applicant proposing landscaping/screening must satisfy)

Determine the zone (RA‑S, R‑1, CR) for the parcel and apply the district rules above; check § 5-2C‑4 / § 5-2E‑5 / § 5-2F‑5 as applicable.
If any tree removal or severe pruning is proposed, prepare a tree report by a qualified specialist and apply for a tree permit (§ 5-8-5) or minor tree permit (§ 5-8-7) as appropriate; include protection and replacement proposals.
Provide a landscape plan that complies with the California Model Water Efficient Landscape Ordinance and the HHCA standards; cite § 5-10-1 and § 5-10-2 on the plan.
If you propose fences/walls: show fence heights, materials, relationship to easements, and note compliance with boundary fence rules (height min/max and no barbed wire) per § 5-2C‑5; identify where a masonry separation wall is required (CR abutting residential).
If mechanical equipment will be placed near a setback, show permanent screening (wood or masonry) consistent with § 5-2C‑4 F.
Confirm whether architectural/site plan review is required (especially in CR) and submit materials consistent with § 5-2F‑6.
If the Hidden Hills Community Association review/approval is required for fences or architectural consistency, obtain HHCA certification where the code references it. (Code requires HHCA approval in places; see the yard/fence provisions immediately preceding § 5-2C‑5.)

Risks & Ambiguities

Issue	Why it matters	What to verify
HHCA architectural standards overlay	City code repeatedly defers to Hidden Hills Community Association (HHCA) architectural standards for fences/landscapes; HHCA can impose additional requirements.	Verify HHCA subcommittee review requirements and obtain HHCA certification when code references it (see the fences/yards text adjacent to § 5-2C‑5).
Which tree removals need City tree permit vs. minor permit	Different thresholds and replacement ratios apply (e.g., minor permit limits historic tree actions to ≤2 trees). Getting this wrong risks misdemeanor penalties.	Confirm whether your proposed activity meets § 5-8-5 or the narrower § 5-8-7 minor permit criteria and follow replacement/bond rules.
Setback fence/retaining wall numerical application on sloped lots	The code allows stepped walls that may “appear” taller; the “minor structure” status can be lost if stepped walls look like a single taller wall.	Verify on your parcel how the code treats stepped walls and confirm measurement method with the Planning Director (see the retaining wall language in § 5-2C‑4).
Fire/fuel‑modification vs. landscape screening	State WUI/fire clearance rules can require removal of combustible vegetation or specify noncombustible screens near structures; that can conflict with screening goals.	The municipal code adopts water‑efficient landscaping but does not fully substitute for fire clearance rules; verify fuel modification and Fire District guidance and, if applicable, the state Wildland‑Urban Interface guidance. (See local WUI/fire codes for details — not fully codified here.) Not found in retrieved materials for detailed clearance distances.
Tree species / HHCA plant lists	The City requires water‑efficient plant choices and HHCA approval; HHCA may prefer certain species for visual character and fire resistance.	Submit plant palette that cites § 5-10-2 and HHCA standards; confirm HHCA preferred or prohibited lists.

Plain‑English summary

Hidden Hills requires permits and design review for most landscaping and screening that affect setbacks, protected trees, or neighborhood appearance: get a tree report and tree permit for removals, follow the City’s water‑efficient landscape rules (and HHCA standards), keep fence/wall heights and materials inside the numeric limits and avoid barbed wire, and expect architectural/site plan review for anything that changes walls, fences or large landscaping areas. Key rules live in the tree chapter (§ 5-8-5 et seq.), the water‑efficient landscaping chapter (§ 5-10-1/2), and the yard/fence/architectural chapters (§ 5-2C‑4 / § 5-2C‑5 / § 5-2F‑6).

Source References

§ 5-8-5 (Tree permit — permit, replacement, protection, findings)
§ 5-8-6 (Exemptions from tree chapter)
§ 5-8-7 (Minor tree permit — limits and replacement)
§ 5-8-8 (Tree value / bond / appeals)
§ 5-10-1, § 5-10-2, § 5-10-3 (Adoption of California Model Water Efficient Landscape Ordinance; HHCA compliance)
§ 5-2C‑4 (Yards / Minor structures / open fencing / retaining walls / projections — RA‑S yard rules and allowances; paragraph directly preceding § 5-2C‑5)
§ 5-2C‑5 (Other requirements — barbed‑wire prohibition; boundary fence heights; lighting limits)
§ 5-2E‑5 (R‑1: where silent, R‑1 follows RA‑S)
§ 5-2F‑1, § 5-2F‑5, § 5-2F‑6 (CR zone permitted uses, development standards, and required architectural/site plan review)
§ 5-2O‑3 (SB 9 development standards that include tree protection and ridgeline/lot development constraints)
State-level wildland-urban interface and fire code excerpts included in uploaded materials (for context on fire‑related screening/clearance; not a substitute for local Fire District rules).

Sources

Retrieved passages

Hidden Hills Zoning Code (Title and) High relevance
Hidden Hills Zoning Code (Section and) High relevance
Hidden Hills Zoning Code (Section prior) High relevance
CWUIC § 65850.6 (Title 24) High relevance
Hidden Hills Zoning Code (§ 2) Medium relevance
CBC § 5 (Section 5-5B-1) Medium relevance
Hidden Hills Zoning Code (Title and) Medium relevance
Hidden Hills Zoning Code (Section 5-13-4) Medium relevance
Hidden Hills Zoning Code Medium relevance
Hidden Hills Zoning Code Medium relevance
Hidden Hills Zoning Code (§ 2) Medium relevance
Hidden Hills Zoning Code (Section 1-9-1) Medium relevance

Cited sections

Official Hidden Hills code library

Frequently asked questions

What rules control when I must get a tree permit in Hidden Hills?

If you propose to severely prune, relocate or remove protected trees you must apply for a tree permit under § 5-8-5; the Planning Director engages a qualified tree specialist, replacement and protection measures (including chain‑link fencing at driplines, supervision of excavation, and replacement ratios) are part of that permit.

Can I build a perimeter fence at the property line and how tall can it be?

Boundary/perimeter fences are allowed but must conform to Title V rules; boundary fences are limited to not less than 3 ft 6 in and not more than 6 ft in height and must not be placed in easements where prohibited. The code also prohibits barbed‑wire fences along bridle trails or as perimeter fences (§ 5-2C‑5).

Is open fencing allowed in setbacks on an RA‑S or R‑1 lot?

Yes — the RA‑S “minor structures / yard” rules specifically list open fencing as allowed in side and rear setbacks and allow limited low retaining walls when they meet the dimensional limits; R‑1 borrows RA‑S rules where it is silent (see § 5-2C‑4 and § 5-2E‑5).

Do I need to show landscaping on my site plan for a commercial project in Hidden Hills?

Yes. In the CR zone (and for any project requiring architectural/site plan review) landscaping and screening are part of the required submittal; the Planning Agency must review and approve the site/architectural plan under § 5-2F‑6, and § 5-2F‑5.F requires yard areas to be landscaped and to provide effective visual barriers where adjacent to residential property.

What are the replacement tree rules if the City allows me to remove trees?

The Planning Director or City Council may require replacement trees; the standard replacement ratio in discretionary permits is four replacement trees for each tree removed, but the Planning Director may require no less than two for one as an absolute minimum when issuing permits administratively — see § 5-8-5.C.2.

Are there special rules for screening mechanical equipment or A/C units?

Yes — the ordinance allows air‑conditioning units or mechanical equipment to encroach into side/rear setbacks up to 4 feet only if permanently screened with a wood or masonry fence, per the projections / setback allowances. § 5-2C‑4 F.

Does Hidden Hills require water‑efficient landscaping?

Yes. Hidden Hills adopted the California Model Water Efficient Landscape Ordinance; all landscape plans must comply with that state model and also meet any HHCA standards required for architectural approval (§ 5-10-1 and § 5-10-2).

If my lot is sloped, can I build stepped retaining walls for screening?

The code allows retaining walls up to 3 feet in many contexts but cautions that multiple stepped walls which appear like one taller wall may not be treated as “minor structures.” Confirm the measuring method and whether stepped walls will cause loss of “minor structure” status with the Planning Director (see the retaining wall language in the yard/minor structure rules). § 5-2C‑4.

Do wireless or utility facilities (transformers, antennas) have landscaping/screening requirements?

Yes. Wireless communications and similar facilities must be located where topography/vegetation provide the best screening; where screening is insufficient, applicants must provide landscaping plans acceptable to the City Engineer and may be required to plant trees/shrubs to block lines of sight. See the utility/wireless facility screening language in the code (various sections including the wireless facilities visibility and screening provisions). § 5-12- (see wireless facility subchapter) and related screening paragraphs.

What if my proposed landscaping conflicts with fire clearance requirements?

The zoning code does not replace Fire District or state wildland‑urban interface rules. Fuel modification and defensible‑space requirements can force removal or alteration of landscape screening. Verify clearance/fuel modification rules with the LA County Fire Protection District and cross‑check against the City’s code; the City’s files reference state WUI guidance in other uploaded materials (context only). Not fully set out in the zoning chapters — verify with the jurisdiction.

Ask about any Hidden Hills property

Get a cited, plain-English answer on Hidden Hills zoning, setbacks, FAR, ADUs and permits — for any address.

Start Free Trial