Western San Fernando Valley · LA County
ADU permits in Hidden Hills
Zip codes:91302
Hidden Hills is a small, gated independent city of about 1,900 people in the western San Fernando Valley (SFV), nestled between Calabasas and Bell Canyon. The entire city is a private gated community with equestrian-zoned single-family lots typically 1 acre or larger. Permits go through the small City of Hidden Hills civic office; planning and building services are largely contracted to outside firms given the city's small size.
Independent city — not LADBS
Hidden Hills runs its own building department. Permits go through City of Hidden Hills ↗, not the Los Angeles Department of Building and Safety (LADBS). Our address checker pulls real zoning + overlay data for any Los Angeles County address. The Hidden Hills ordinance breakdown below covers the city-specific permit path.
Hidden Hills by the numbers
Rounded figures from the 2020 US Census, LA County Assessor parcel data, and the city's own published reports. Estimates only — your specific lot can vary widely.
Population
1,900
2020 Census
Single-family homes
~600
LA County Assessor
Median lot size
50,000 sqft
Approximate
Median home value
$5.2M
Zillow / Redfin
What makes Hidden Hills different
Hidden Hills was historically one of the most restrictive ADU jurisdictions in California. State preemption (Gov Code §65852.2) forced alignment with state minimums starting in 2020, but the city retains aggressive design review on equestrian-character protection. The entire city is within the Very High Fire Hazard Severity Zone (VHFHSZ).
Hidden Hills ADU ordinance — the rules that apply
Last verified: 2026-05-12
The current ADU rules in Hidden Hills, sourced from the city's published ordinance and verified against CA Government Code §65852.2 (which preempts local rules stricter than state baselines). When you see "state default," that means the city can't reduce below this number under state law.
| Max detached ADU size | 1,200 sqft (state default) |
| Max ADU height | 16 ft / 18 ft with second-story setbacks |
| Setbacks | 4 ft side / 4 ft rear (state minimum) |
| Design review | Required for all ADUs — equestrian + ranch-style architectural compatibility Mandatory in Hidden Hills. Adds 60-90 days. |
| VHFHSZ construction | Class A roofing, ember-resistant venting, fire-rated wall assemblies Citywide. Adds roughly 7% to construction cost. |
| Equestrian zoning | Many lots have horse-keeping rights; ADU placement must preserve corral / paddock setbacks |
| Local processing time | 90-120 days typical with design review |
| Pre-approved standard plans | None city-specific |
Source: City of Hidden Hills ↗
Active overlays + extra rules in Hidden Hills
City overlays + state-level designations that hit a meaningful share of Hidden Hills parcels. Each affects what you can build, how long it takes, or how much it costs.
Very High Fire Hazard Severity Zone (VHFHSZ)
~100% of parcelsCitywide. Triggers Chapter 7A construction requirements + defensible-space inspection at final.
Equestrian-character protection
~100% of parcelsLocal design review prioritizes ranch + equestrian aesthetics. ADUs out of architectural character face significant design-review pushback.
Mulholland-adjacent ridgeline protection
~25% of parcelsLots visible from Mulholland Drive or recognized view corridors face additional height + massing constraints.
Watch-outs specific to Hidden Hills
Patterns we see across Hidden HillsADU permits. None are dealbreakers — they're just the things people get wrong most often.
- 01
Design review here is unusually aggressive
Hidden Hills design review is heavier than most LA-area cities. Architects experienced with the city's review board are worth their fees — outside-the-norm designs (modern, glass-heavy, non-ranch) face long pushback cycles.
- 02
Horse-keeping rights affect ADU footprint placement
If your lot has horse-keeping rights, you must preserve setbacks from corrals and paddocks when placing the ADU. Verify with the city before drafting plans.
- 03
Property-owner-only city — gated access
Vendors, contractors, designers, and inspectors all need to coordinate gate access with the homeowner. Small thing, but adds project-coordination overhead.
- 04
Las Virgenes Unified school fees apply
Las Virgenes Unified School District (LVUSD) charges school facility fees on ADUs over 500 sqft.
Need a person, not a wizard?
Routes that fit Hidden Hills
Based on what we know about Hidden Hills, these are the lead types that usually make sense here. Pick whichever fits your situation. All free, no obligation.
Complex permit context
Request a Hidden Hills permit referral
Coastal, hillside, historic, fire-zone, or multi-overlay parcels in Hidden Hills usually mean a permit expediter pays for itself in saved months. We work with vetted Los Angeles permit expediters and expeditors (both spellings) who've handled Hidden Hills projects.
Complex permit context
Request a Hidden Hills permit referral
Coastal, hillside, historic, fire-zone, or multi-overlay parcels in Hidden Hills usually mean a permit expediter pays for itself in saved months. We work with vetted Los Angeles permit expediters and expeditors (both spellings) who've handled Hidden Hills projects.
Talk to our financing broker
Want someone to walk you through your options?
Our in-house broker has 30+ years in LA mortgage and ADU financing. He'll lay out HELOC, construction-to-perm, and ADU-specific products like Renofi against your situation — free, no obligation.
Talk to our financing broker
Want someone to walk you through your options?
Our in-house broker has 30+ years in LA mortgage and ADU financing. He'll lay out HELOC, construction-to-perm, and ADU-specific products like Renofi against your situation — free, no obligation.
Plans that fit Hidden Hills lots
Hidden Hillsdoesn't maintain a city-specific pre-approved plan library the way the Los Angeles Department of Building and Safety (LADBS) does. California Department of Housing and Community Development (HCD)-approved prefab (which bypasses local plan check) and custom designer plans are the main paths:
Amenities + civic services in Hidden Hills
Parks, libraries, and the school district that serve the area. Context that matters for renter appeal, family relocation, and long-term resale.
Public schools
School assignments vary by exact address. The district + notable schools below cover most of the area.
District
Las Virgenes Unified School District (LVUSD)
Notable schools in the area
- Calabasas High School (LVUSD)
- A.E. Wright Middle School
LVUSD also serves Calabasas + Agoura Hills + Westlake Village. Top-performing public district.
Getting around Hidden Hills
Car-only. Gated private city with no public transit.
Transit + walkability
Walkability
Not applicable — gated private community.
Nearby airports
Distance + type for each major Los Angeles-area airport reachable from Hidden Hills. Useful for travel, commute, and any flight-path noise concerns on specific parcels.
Van Nuys Airport (VNY)
~16 miGeneral aviation
Hollywood Burbank Airport (BUR)
~24 miRegional / domestic
Closest commercial airport.
Los Angeles International (LAX)
~35 miInternational
Community + landmarks in Hidden Hills
Annual events, landmarks, and the places that anchor the area's identity. Context for renter appeal and long-term resale.
What makes Hidden Hills Hidden Hills
Landmark
Hidden Hills Community Church
Historic 1950s community church inside the gated city.
Park
Round Meadow Park (LVUSD-adjacent)
Public park technically adjacent to Hidden Hills' eastern edge, used by LVUSD schools.
Nearby areas to Hidden Hills
Other Los Angeles-area pages worth a look. Each one runs different Accessory Dwelling Unit (ADU) rules depending on jurisdiction — we show you what changes when you cross a city or county line.
Independent city
Calabasas →
Large lots and high home values make Calabasas an attractive Accessory Dwelling Unit (ADU) market, but Very High Fire Hazard Severity Zone (VHFHSZ) rules and hillside-area restrictions add meaningful cost compared to flat-lot City of Los Angeles builds.
LA City
Woodland Hills →
Big lots, R1-1 zoning, and a transit corridor along Ventura make Woodland Hills one of the highest-ADU-permit neighborhoods in LA — but the hillside south of the Boulevard adds real cost.
Frequently asked questions about Hidden Hills ADUs
›Can I build an ADU in Hidden Hills?
Yes. Hidden Hills allows ADUs under its local ordinance, aligned with California Government Code §65852.2 (the state baseline that preempts overly-strict local rules). Most single-family lots can host one ADU plus one JADU. Permits go through City of Hidden Hills, not LADBS — see the ordinance table above for the specific rules.
›How does Hidden Hills differ from LA City for ADU permits?
Three main differences: the permit agency (City of Hidden Hills vs. LADBS), the local ordinance details (each city has some flexibility above the state baseline), and the timeline (some cities are faster, some slower than LA's 60-day plan check). See the ordinance breakdown above for the specifics on each.
›How much does it cost to build an ADU in Hidden Hills?
Median home value in Hidden Hills is around $5.2M, which usually means lot economics support a quality ADU build of $200K–$400K all-in. Hillside, coastal, or VHFHSZ lots add 7–25% on top. HCD-prefab units (Connect Homes, Cover, Plant Prefab) bypass local plan check entirely and typically run $190K–$350K turnkey.
›Does Hidden Hills have pre-approved standard plans like LA's YOU-ADU?
No. Unlike LADBS, Hidden Hills does not maintain a city-specific pre-approved plan library. The two faster paths are an HCD-approved prefab (factory-certified, skips local plan check) or a custom designer drawing for your lot. The slower path is a fully custom architect-led design.
›Will the PermitPathLA wizard work for my Hidden Hills address?
Yes. The wizard pulls real zoning, overlay, and parcel data for any Los Angeles County address, including Hidden Hills. What you'll see today: feasibility for your specific lot, the overlays that apply, and a routing summary pointing at City of Hidden Hills for the permit submittal. Deeper Hidden Hills-specific permit walkthroughs are next on the roadmap as we expand from LADBS into the independent-city ordinances.
Ready to see what your Hidden Hills lot can do?
Our free address checker pulls real zoning, overlay, and parcel data for any Los Angeles County address — including Hidden Hills. Start there and we'll surface what applies to your specific lot.
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