California ADU rules · Los Angeles County
Can I Build an ADU in Westlake Village?
Yes — you can build an ADU in Westlake Village. California's statewide ADU law requires every city, including Westlake Village, to approve a qualifying accessory dwelling unit by right, plus a junior ADU (JADU) on a single-family lot. What varies city to city are the local specifics below.
Can you build one?
ADUs allowed
CA state lawYes — by right
ADUs and JADUs are allowed by right in all residential and mixed-use zones; ministerial approval, no hearing.
Units on a single-family lot
Local rule1 ADU (attached or detached) + 1 JADU per lot; in VHFHSZ: only 1 ADU or 1 JADU
Fire zone limits to 1 ADU or 1 JADU per lot.
Units on a multifamily lot
Local ruleConversions: at least 1 or up to 25% of units; up to 2 detached ADUs per lot
Detached ADUs on multifamily lots capped at 2.
Junior ADU (JADU)
Local ruleAllowed
JADUs allowed only on single-family lots; not allowed on multifamily lots.
Size & height
Max detached ADU size
Local rule1,000 sq ft
850 sq ft for studio/1-bedroom; 1,000 sq ft for 2+ bedrooms; covered porches/balconies count toward max.
Max attached ADU size
Local rule850 sq ft (studio/1-bedroom) or 1,000 sq ft (2+ bedrooms), or 50% of primary, whichever is less; must allow at least 850/1,000
Covered porches/balconies count toward max.
Guaranteed minimum size
CA state law800 sq ft
An 800 sq ft ADU must be allowed regardless of FAR/lot-coverage caps; a city also cannot cap an attached ADU below 850 sq ft (1,000 for 2+ bedrooms).
Max JADU size
CA state law500 sq ft
Max height
CA state law16 ft
16 ft baseline; cities must allow 18 ft within ½ mi of a major transit stop or where the primary dwelling is two-story, and 20 ft on a lot with a multistory multifamily building.
Setbacks
Side setback
CA state law4 ft
A city cannot require more than 4 ft side or rear setback; conversions of existing structures are exempt.
Rear setback
CA state law4 ft
Front setback
Local ruleMust meet primary residence front setback unless it would preclude an 800 sq ft, 16 ft tall ADU with 4 ft side/rear setbacks
City must allow state-minimum ADU if front setback would otherwise block it.
Separation from main house
CA state lawNone required
No statewide separation requirement between the ADU and the primary dwelling.
Parking
Parking required
Local ruleUp to 1 space
1 off-street space per ADU with at least 1 bedroom; exemptions per state law.
Transit parking exemption
CA state lawYes — no parking required near transit & for conversions
No parking may be required within ½ mi walking distance of transit, in a historic district, for an ADU within an existing structure, within one block of car-share, or in certain permit-parking areas.
Garage-conversion replacement parking
Local ruleNot required
No replacement parking required for primary residence when garage/carport is converted.
Approval, timeline & cost
Approval path
CA state lawMinisterial (by right)
No public hearing or discretionary design review for a qualifying ADU.
Approval timeline
CA state law60 days
The agency must act within 60 days of a complete application — and the ADU is deemed approved if it does not.
Owner-occupancy
CA state lawOnly for a JADU
No owner-occupancy requirement for ADUs (the prior sunset was removed). A JADU may require owner-occupancy, principally where it shares sanitation with the main house.
Impact-fee waiver
CA state lawWaived under 750 sq ft
An ADU of 750 sq ft or less pays no impact fees (the 750 sq ft threshold itself is exempt under § 66311.5); larger ADUs pay fees proportional to the primary dwelling. JADUs (≤ 500 sq ft) are exempt.
Permits required
Local ruleZoning clearance, Building permit, Demolition permit (if applicable)
Demolition permit processed concurrently if needed.
Westlake Village-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
Very High Fire Hazard Severity Zone (VHFHSZ)
Only 1 ADU or 1 JADU allowed per lot; must comply with brush clearance and sprinklers if required for main house.
Historic District
No parking required for ADUs in historic districts.
Westlake Village caps detached and attached ADUs at 1,000 sq ft (2+ bedrooms) or 850 sq ft (studio/1-bedroom), and allows only 2 detached ADUs on multifamily lots. In the Very High Fire Hazard Severity Zone, only 1 ADU or 1 JADU is permitted per lot.
Frequently asked questions
Can I build an ADU in Westlake Village?
Yes. California's statewide ADU law requires Westlake Village to approve a qualifying accessory dwelling unit ministerial (by right), plus a junior ADU (JADU) on a single-family lot.
How big can an ADU be in Westlake Village?
A detached ADU of at least 1,000 sq ft must be allowed, and an ADU of 800 sq ft can never be zoned out by floor-area or lot-coverage limits. A JADU can be up to 500 sq ft.
What are the setback requirements for an ADU in Westlake Village?
Side and rear setbacks are limited to 4 ft. Must meet primary residence front setback unless it would preclude an 800 sq ft, 16 ft tall ADU with 4 ft side/rear setbacks.
Is parking required for an ADU in Westlake Village?
Up to 1 space. No parking can be required within ½ mile of transit, for conversions, or for units inside the primary home. When a garage is converted, replacement parking is not required.
How long does ADU approval take in Westlake Village?
A complete application must be acted on within 60 days, with ministerial (by right) — no public hearing or discretionary design review for a qualifying ADU.
Do I have to live on the property to build an ADU in Westlake Village?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Westlake Village Municipal Code §9.14.070–9.14.080, Ord. No. 297-22, §2, 12-14-2022
- WLVMC §9.14.070(C), (D)
- WLVMC §9.14.070(C)
- WLVMC §9.14.070(E)
- WLVMC §9.14.070(B)(3)(a)
- WLVMC §9.14.070(B)(3)(b)
- WLVMC §9.14.070(B)(5)
- WLVMC §9.14.070(B)(7)-(8)
- WLVMC §9.14.070(B)(9)
- WLVMC §9.14.080(A)-(C)
- WLVMC §9.14.070(D)
- WLVMC §9.14.070(B)(8)(b)
- Cal. Gov. Code §§ 66310–66342 (ADU Law)
- HCD 2025 Accessory Dwelling Unit Handbook
- Cal. Gov. Code § 66317 (ministerial approval, 60-day deadline)
- Cal. Gov. Code § 66321 (size minimums & height)
- Cal. Gov. Code § 66333 (junior ADUs)
- Cal. Gov. Code § 66323 (by-right ADU/JADU, 800 sq ft, 4-ft setbacks)
- Cal. Gov. Code § 66322 (ADU parking; § 66334 covers JADU parking)
- Cal. Gov. Code § 66315 (owner-occupancy)
- Cal. Gov. Code § 66311.5 (impact fees: none for an ADU ≤ 750 sq ft or JADU ≤ 500 sq ft)
Last updated 2026-06-25. This is an AI-assisted summary of Westlake Village's ADU rules, drawn from its published ordinance and California ADU law — general information, not legal advice, and it may be incomplete or out of date. Verify the controlling rule for your specific parcel with Westlake Village Planning before relying on it.
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