Local zoning · Hidden Hills

Hidden Hills — Zoning

Q: What can I build on an R-1 lot in Hidden Hills?

You may build a single‑family residence and customary accessory buildings consistent with the R‑1 rules; the R‑1 standards require a minimum lot area of 20,000 sq ft , maximum coverage 30% , and front/side/rear setbacks set in § 5-2E-2 and § 5-2E-4 . Verify your parcel’s exact compliance (lot width, encumbrances) with City records § 5-2E-2; § 5-2E-4 .

Q: What are Hidden Hills’ setback requirements?

Setbacks depend on the zone: RA‑S front 50 ft; side 15/25 ft; rear 50 ft ( § 5-2C-4 ). R‑1 front 35 ft; side 25/5 ft; rear 25/15/5 ft depending on adjacent zoning ( § 5-2E-4 ) — always confirm the measurement point (road easement line vs property line) in the cited section § 5-2C-4; § 5-2E-4 .

Q: What are the RA‑S‑2 height limits?

RA‑S‑2 uses a size-based height matrix in § 5-2D-2 . For example, a main building ≤ 6,000 sq ft that is single‑story has a height envelope of 22 ft and a height cap of 26 ft ; larger footprints and two‑story buildings have higher envelope/cap numbers up to 30–34 ft depending on size and story count — read § 5-2D-2 for the full matrix and exclusions for subterranean area .

Q: Can I build an ADU and what setbacks apply?

Hidden Hills’ ADU rules are in Article P ( § 5-2P ). Many ADUs must observe 4‑ft side and rear setbacks under certain subsections, have specific lot‑coverage limits for ADUs, and generally one off‑street parking space is required except where exemptions apply (transit proximity, historic district, conversion of existing structure, etc.). Consult § 5-2P-7 for ADU setback/parking details and the City’s ADU page for local process steps .

Q: How does SB 9 processing work in Hidden Hills?

Hidden Hills added objective SB 9 standards in Article O . RA‑S, RA‑S‑2 and R‑1 are treated as single‑family zones under that Article and SB9 lot splits / two‑unit projects can be processed ministerially if they meet the objective requirements in § 5-2O ; ministerial denials require specific written findings § 5-2O-6 .

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

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Last reviewed: July 2, 2026

Overview

Hidden Hills’ zoning rules are adopted in the City’s Land Use and Development Title (commonly the local zoning regulations) and establish six local zones plus overlays, an Official Zoning Map, and objective standards for development. The ordinance lists the zone names and basic limits, prescribes setbacks, lot sizes and height envelopes, and sets special rules for overlays, site-plan/design review and ADUs. See the City’s zoning & planning overview for program-level context. § 5-2B-2 and § 5-2B-3 are the controlling map-and-zone authorities .

How I use the City documents in this page

Every numeric standard below is pulled from the Hidden Hills Land Use & Development ordinance and is cited to the controlling code paragraph (with the § number) and the file excerpt where it appears. Where the ordinance text does not specify a particular item, I mark that as “Not found in retrieved materials” and tell you what to verify with the City.

District-by-district breakdown (purpose, uses, key standards, where it applies)

Note: the City establishes the zones in § 5-2B-2: RA-S, RA-S-2, R-1, C-R, C-U, and the Affordable Housing Overlay (AH-O) .

RA-S (Residential Agriculture Suburban)

Purpose: Large-lot, rural/suburban single-family estates and agricultural accessory uses; preserves the City’s rural character. See the City’s Development Standards for design-level detail.
Typical permitted uses: Primary single-family residence and customary accessory buildings (private garage, children's playhouse, greenhouses, tool houses, domestic animal structures excluding pigs/hogs used commercially) — § 5-2C-1 .
Key dimensional standards:
- Front setback: 50 ft measured from road easement line § 5-2C-4 .
- Side setback: 15 ft (from easement) or 25 ft (from side lot line); corner side-yard rules apply § 5-2C-4 .
- Rear setback: 50 ft § 5-2C-4 .
- Other: special limits on front-yard structures and outdoor lighting (see § 5-2C-5) .
Where it applies: parcels shown as RA‑S on the Official Zoning Map; map is maintained in City Clerk records § 5-2B-3 .

RA-S-2 (Residential Agriculture Suburban‑2)

Purpose: Like RA‑S but with tailored height and ADU allowances for larger or estate properties; included in the City’s single‑family zone set used for SB 9 rules § 5-2D-1; § 5-2O-1 .
Typical permitted uses: All uses permitted in RA‑S, plus limited accessory uses described in § 5-2D-1 (e.g., demonstration estate exceptions). Maximum ADU size in the zone is specifically limited (see ADU article) — § 5-2D-1 .
Key dimensional/height standards:
- Variable height envelope tied to main-building size: examples include 22 ft envelope / 26 ft cap for single‑story buildings ≤ 6,000 sq ft; taller caps for larger buildings up to 30–34 ft depending on footprint and stories — see § 5-2D-2 for the size/height matrix .
- Secondary-story massing limits (second-story floor area ≤ 50% of first-story footprint) § 5-2D-2 .
Where it applies: parcels designated RA‑S‑2 on the Official Zoning Map § 5-2B-2 .

R‑1 (Residential)

Purpose: Standard residential district (smaller-lot single-family) with development limits that generally mirror RA‑S except for reduced setback and lot-size requirements in places.
Typical permitted uses: Single‑family dwellings and accessory uses (subject to the same accessory-use rules as RA‑S) § 5-2E-1 (permitted uses appear in Article E) .
Key dimensional standards:
- Minimum lot area: 20,000 sq ft § 5-2E-2 A .
- Maximum lot coverage: 30% for all buildings and roofed structures § 5-2E-2 C .
- Front setback: 35 ft § 5-2E-4 A .
- Side setback: 25 ft if abutting RA‑S; otherwise 5 ft if abutting R‑1 or commercial § 5-2E-4 B .
- Rear setback: 25 ft if abutting RA‑S; 15 ft if abutting R‑1; 5 ft if abutting commercial § 5-2E-4 C .
- Height & second-story rules: second-story ≤ 50% of first-story footprint; massing pushed toward rear § 5-2E-3 .
Where it applies: parcels zoned R‑1 on the Official Zoning Map § 5-2B-2 .

C‑R (Commercial‑Restricted)

Purpose: Limited commercial uses designed to be compatible with the surrounding residential community; the ordinance requires that business activity be conducted in enclosed structures and that commercial architecture reflect residential character.
Typical permitted uses: Professional, executive, administrative and sales offices (medical/dental excluded), plus limited housing under the Affordable Housing Overlay; emergency shelters allowed subject to standards § 5-2F-1; § 5-2F-8 .
Conditional uses: restaurants, retail/service stores, similar uses only with a conditional use permit § 5-2F-2 .
Key standards & process:
- Architecture & site plan review required for new construction; the Planning Agency applies specific architectural controls and findings § 5-2F-6 (architectural and site plan review) .
- The Planning Agency can grant incentives like FAR up to 1.2:1 and reduced yards in exchange for design tradeoffs (but never reduce a yard abutting residential property below 10 ft) § 5-2F-6 C .
Where it applies: parcels shown C‑R on the Official Zoning Map § 5-2B-2 .

C‑U (Community Uses)

Purpose & details: The ordinance establishes C‑U as a zone; specific permitted uses and standards are in Article(s) for community uses. For parcel-by-parcel rules, verify the applicable Article in the Code. The general zoning-map authority is § 5-2B-3 .
Code reference: Not all C‑U subsections were retrieved in the excerpt I was provided; verify with the City Clerk or the full Title 5 text for exact permitted uses and dimensional standards. Verify with the jurisdiction.

Affordable Housing Overlay (AH‑O / AHO)

Purpose: An overlay to the C‑R zone identifying sites where lower‑income multiple‑family dwellings are permitted to meet RHNA (Regional Housing Need Allocation) goals § 5-2F-9 .
Key rules:
- Minimum density: 20 units/acre for lower‑income multiple‑family dwellings § 5-2F-9 E.1 .
- Minimum project size: 16 units § 5-2F-9 E.2 .
- Lower‑income developments must be affordable per the ordinance and subject to site plan review; other permitted uses in the underlying zone may be allowed with site plan review § 5-2F-9 D–F .
Where it applies: parcels designated on the Official Zoning Map as the AHO; the overlay is added to specific C‑R parcels § 5-2F-9 A–B .

Quick reference table — decision‑relevant standards & permitted uses

District / Item	Key decision standards or permitted uses	Code Reference
Zones established	RA‑S, RA‑S‑2, R‑1, C‑R, C‑U, AH‑O (Official list)	§ 5-2B-2
Official Zoning Map	Map adopted and kept on file at City Clerk; amendments noted by ordinance #	§ 5-2B-3
RA‑S	Front 50 ft, Side 15/25 ft, Rear 50 ft; single‑family primary uses and accessory structures	§ 5-2C-4; § 5-2C-1
RA‑S‑2	Permitted uses = RA‑S uses; ADU maximum size restrictions; height envelope matrix (example: 22 ft env / 26 ft cap for ≤6,000 sq ft single‑story)	§ 5-2D-1; § 5-2D-2
R‑1	Min lot 20,000 sq ft; max coverage 30%; Front 35 ft; Side 25 ft (if abutting RA‑S) or 5 ft; Rear 25/15/5 ft	§ 5-2E-2; § 5-2E-4; § 5-2E-3
C‑R	Offices by‑right; restaurants/retail require CUP; architectural & site plan review required; Planning Agency incentives (FAR up to 1.2:1)	§ 5-2F-1; § 5-2F-2; § 5-2F-6
AH‑O (Affordable Housing Overlay)	Allows lower‑income multifamily; min density 20 units/acre, min 16 units, site-plan review and affordability covenants	§ 5-2F-9
ADUs	ADU/JADU standards, setbacks (4‑ft side/rear for many ADUs), parking rules and exceptions — ADU Article P	§ 5-2P-1 et seq.
SB 9 (ministerial lot splits/2-unit rules)	Objective standards for SB 9 development; RA‑S, RA‑S‑2, R‑1 are SB9-eligible single‑family zones; ministerial processing rules in § 5-2O	§ 5-2O-1; § 5-2O-6

How the procedure and reviews interact (practical guidance)

Confirm the parcel’s zone on the Official Zoning Map first (the map is the controlling designation) § 5-2B-3 .
For projects in C‑R or the AH‑O, expect mandatory architectural and site-plan review under § 5-2F-6 and the overlay rules in § 5-2F-9; the Planning Agency applies design findings and can attach conditions or incentives (e.g., FAR up to 1.2:1) .
For residential zones, read both the zone article (RA‑S, RA‑S‑2, R‑1) and the ADU article (§ 5-2P) when adding accessory units; ADU setbacks, coverage, parking exceptions and ministerial timelines are handled in Article P § 5-2P-6/7 and related subsections (architectural matching, parking exceptions, 4‑ft side/rear for many ADUs) .
SB 9 (lot splits / two-unit rules) is implemented by the City with its own objective standards and ministerial processing; read § 5-2O for SB9 standards and the list of eligible zones § 5-2O-1 .

While the City’s zoning controls use, setbacks, heights, and spacing, remember that the City has additional design requirements and a strong role for the Hidden Hills Community Association (HHCA) standards on many projects — see the Planning Director exemptions and HHCA certification language; verify HHCA conditions early in the process (City code references the HHCA in site-plan exemptions and other subsections) .

Checklist (what an applicant must satisfy)

Verify the parcel’s official zone designation on the City’s Official Zoning Map and note any overlays (Official Zoning Map; § 5-2B-3) .
Confirm the proposed use is allowed in that zone (permitted vs conditional vs prohibited) (see the zone article: § 5-2C-1, § 5-2D-1, § 5-2E-1, § 5-2F-1/2) .
Confirm dimensional compliance: lot area, lot width, front/side/rear setbacks, coverage limits and building height envelope for the zone (§ 5-2C-4; § 5-2D-2; § 5-2E-2; § 5-2E-3) .
If proposing ADU/JADU, follow Article P objective ADU standards (setbacks, lot coverage limits, parking rules and ministerial process) § 5-2P and the City’s ADU checklist; consult the City’s ADU page for local instructions and the state ADU law summary. Link to local ADU guidance: Hidden Hills ADUs .
If project is commercial or in AH‑O, prepare architectural/site plan materials and expect Planning Agency review under § 5-2F-6 and AH‑O findings in § 5-2F-9 . Link to the City’s Design Review and Overlay Districts pages for process details.
Check whether the project triggers SB 9 ministerial reviews (if lot split / two‑unit) and comply with objective standards in § 5-2O; ministerial processing rules are in § 5-2O-6 .
Verify parking and landscaping requirements applicable to the project (parking rules for ADUs are in Article P; general parking and landscaping standards appear in the Title) and consult the City’s Parking page. See ADU parking exceptions § 5-2P-7:F and general parking/landscaping standards (Title extracts) .
Coordinate with Hidden Hills Community Association standards early (the ordinance references HHCA certification for some site-plan exemptions and design coordination) .
Confirm Building Code compliance; Hidden Hills adopts the California Building Code (Title 24) — see § 5-5B-1 and link to the California Building Standards Code for reference .

Risks & Ambiguities

Issue	Why it matters	What to verify
Parcel-specific overlay status (AH‑O)	Affordable Housing Overlay imposes different permitted uses, densities and site‑plan requirements (min 20 units/acre, min 16 units) — it materially changes what you can build § 5-2F-9	Confirm whether the parcel is actually mapped as AHO on the Official Zoning Map and whether any recent ordinance amended the overlay designation (verify § 5-2B-3) .
RA‑S‑2 height matrix complexity	Height caps vary by main-building size (different envelope/cap numbers apply for ≤6,000 sq ft, 6–7,000, ≥7,000) — a simple “max height” check can be misleading § 5-2D-2	Review the full text of § 5-2D-2 for the correct envelope/cap that corresponds to the proposed footprint; verify measurement points and exclusion rules (e.g., subterranean excluded) .
ADU sizing, coverage and parking overlap	ADU rules include exceptions (parking exemptions, coverage allowances, 4‑ft setbacks) that interact with zone setbacks and lot coverage limits (Article P, § 5-2P)	Confirm which ADU pathway applies (standard vs optional larger ADU rules), and use Article P checklists; verify parking exceptions under § 5-2P-7:F .
HHCA requirements vs City Code	The Hidden Hills Community Association standards are referenced as part of design review exemptions — HHCA obligations can add private restrictions or approvals beyond City code (architectural standards, fences, etc.) (see Planning Director exemption language)	Obtain HHCA written certification early if relying on the Planning Director exemption; confirm whether CC&Rs / HHCA rules add conditions not in City code.
Official Zoning Map amendments	The map controls actual zoning on the ground; amendments can change a parcel’s zone without broad public awareness § 5-2B-3	Ask City Clerk for the certified Official Zoning Map and amendment history; verify whether ordinance changes (by number/date) affected your parcel.
SB 9 applicability & constraints	SB 9 builds are ministerial if objective standards are met, but Hidden Hills imposes local objective limits (e.g., ridgeline prohibition, slope limits) § 5-2O-3	Confirm site constraints: ridgeline status, slope >25% prohibition, easements, and whether the lot meets SB 9 eligibility per § 5-2O-1 .

Plain-English summary

Hidden Hills’ zoning ordinance divides the city into RA‑S, RA‑S‑2, R‑1, C‑R, C‑U and an Affordable Housing Overlay (AH‑O); each zone lists permitted uses and clear dimensional controls (setbacks, heights, lot area). The Official Zoning Map controls which zone applies to a parcel and design or site-plan review is required in many cases — confirm your parcel’s zone, setbacks and any overlay before designing. Key controlling sections: § 5-2B-2, § 5-2B-3, zone articles (5-2C, 5-2D, 5-2E, 5-2F) and ADU rules in § 5-2P .

Source References

Zones established; Official Zoning Map: § 5-2B-2 and § 5-2B-3 .
RA‑S permitted uses and setbacks: § 5-2C-1 and § 5-2C-4 .
RA‑S‑2 permitted uses and height rules: § 5-2D-1 and § 5-2D-2 .
R‑1 lot size, coverage, height and setbacks: § 5-2E-2, § 5-2E-3, § 5-2E-4 .
C‑R uses, conditional uses, and site-plan/architectural review: § 5-2F-1, § 5-2F-2, § 5-2F-6 .
Affordable Housing Overlay (AH‑O): § 5-2F-9 (purpose, density 20 units/acre, min 16 units, site‑plan rules) .
ADU standards and parking exceptions: Article P — § 5-2P (see setbacks, parking, ministerial rules and exceptions) .
SB 9 objective standards & ministerial processing: § 5-2O-1 and § 5-2O-6 (zones considered single‑family for SB9: RA‑S, RA‑S‑2, R‑1) .
Official adoption of California Building Code (Title 24) referenced by City: § 5-5B-1 .
Additional parking and landscaping standards (non‑ADU general parking requirements, landscaped area, and incentives): Title extracts in parking/landscaping sections (see parking and landsc. subsections) .

If you want the full text of any of the cited sections, I can extract the specific article/subsection and show it to you. For site‑specific questions (parcel lines, exact mapped overlays, HHCA covenants), verify with the City Clerk and the HHCA; the Official Zoning Map and recorded ordinances control actual parcel designations § 5-2B-3 .

Sources

Retrieved passages

Hidden Hills Zoning Code (ARTICLE B.) Medium relevance
Hidden Hills Zoning Code (Section 65584) Medium relevance
Hidden Hills Zoning Code (Section prior) Medium relevance
Hidden Hills Zoning Code (Section as) Medium relevance
Hidden Hills Zoning Code (Section 5-9-2) Medium relevance
Hidden Hills Zoning Code (TITLE 5) Medium relevance
Hidden Hills Zoning Code (§ 2) Medium relevance
Hidden Hills Zoning Code (§ 1) Medium relevance
CFC § 5 (ARTICLE O.) Medium relevance
Hidden Hills Zoning Code (ARTICLE D.) Medium relevance
Hidden Hills Zoning Code (§ 4) Medium relevance
Hidden Hills Zoning Code (Title shall) Medium relevance
Hidden Hills Zoning Code (§ 4) Medium relevance
CBC § 5 (Section 5-5B-1) Medium relevance
Hidden Hills Zoning Code (Chapter may) Medium relevance
Hidden Hills Zoning Code Medium relevance
Hidden Hills Zoning Code (Title and) Medium relevance
California Building Code Medium relevance
Hidden Hills Zoning Code (Title and) Medium relevance

Cited sections

Official Hidden Hills code library

Frequently asked questions

What can I build on an R-1 lot in Hidden Hills?

You may build a single‑family residence and customary accessory buildings consistent with the R‑1 rules; the R‑1 standards require a minimum lot area of 20,000 sq ft, maximum coverage 30%, and front/side/rear setbacks set in § 5-2E-2 and § 5-2E-4. Verify your parcel’s exact compliance (lot width, encumbrances) with City records § 5-2E-2; § 5-2E-4 .

What are Hidden Hills’ setback requirements?

Setbacks depend on the zone: RA‑S front 50 ft; side 15/25 ft; rear 50 ft (§ 5-2C-4). R‑1 front 35 ft; side 25/5 ft; rear 25/15/5 ft depending on adjacent zoning (§ 5-2E-4) — always confirm the measurement point (road easement line vs property line) in the cited section § 5-2C-4; § 5-2E-4 .

Do I need design review in Hidden Hills?

Many projects require architectural and site plan review: commercial zone projects (C‑R) explicitly require architectural/site plan review under § 5-2F-6. Some residential projects also require review or are subject to Planning Director/Planning Agency review depending on scale and compliance; check the site-plan review rules and exemptions in the relevant zone article (see RA‑S site-plan language and exemptions) (see § 5-2F-6 and related site-plan rules) .

Where is the Official Zoning Map and how binding is it?

The Official Zoning Map is re‑adopted by ordinance and must be kept on file in the office of the City Clerk; “All property within the City is hereby placed in such zones as indicated on this Map,” so it controls what zone applies to each parcel § 5-2B-3 .

What are the RA‑S‑2 height limits?

RA‑S‑2 uses a size-based height matrix in § 5-2D-2. For example, a main building ≤ 6,000 sq ft that is single‑story has a height envelope of 22 ft and a height cap of 26 ft; larger footprints and two‑story buildings have higher envelope/cap numbers up to 30–34 ft depending on size and story count — read § 5-2D-2 for the full matrix and exclusions for subterranean area .

Can I build an ADU and what setbacks apply?

Hidden Hills’ ADU rules are in Article P (§ 5-2P). Many ADUs must observe 4‑ft side and rear setbacks under certain subsections, have specific lot‑coverage limits for ADUs, and generally one off‑street parking space is required except where exemptions apply (transit proximity, historic district, conversion of existing structure, etc.). Consult § 5-2P-7 for ADU setback/parking details and the City’s ADU page for local process steps .

If my lot is in the AH‑O, what density is required?

The Affordable Housing Overlay requires lower‑income multiple‑family developments to meet a minimum density of 20 units per acre and a minimum of 16 units per project; developments must comply with the overlay’s development and affordability rules in § 5-2F-9 .

How does SB 9 processing work in Hidden Hills?

Hidden Hills added objective SB 9 standards in Article O. RA‑S, RA‑S‑2 and R‑1 are treated as single‑family zones under that Article and SB9 lot splits / two‑unit projects can be processed ministerially if they meet the objective requirements in § 5-2O; ministerial denials require specific written findings § 5-2O-6 .

Where do I confirm parking and landscape rules for my project?

General parking and landscaping requirements are in the Title (parking/landscaping extracts and ADU parking exceptions). ADU parking exceptions and general parking standards are found in § 5-2P-7 and parking/landscaping subsections in the ordinance excerpts; see the City’s Parking page for local instructions § 5-2P-7; Title extracts .

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