ADU Rules in Los Angeles, CA (2026)

Los Angeles, CA permits accessory dwelling units (ADUs) on residential properties. ADUs — also called granny flats, in-law units, backyard cottages, or secondary suites — are secondary housing units on a single-family or multifamily lot. California state law actively preempts local restrictions, making ADU approval a streamlined ministerial process. In Los Angeles, the LA Department of Building and Safety (LADBS) handles ADU permit applications. Below you will find the current size limits, setbacks, fees, and timeline for building an ADU in Los Angeles.

ADU Size Limits

ADU Size Limits in Los Angeles: Detached ADU: size varies by zoning — see official source (max height: varies — see official source). Attached ADU: size varies by zoning — see official source. Junior ADU (JADU): up to 500 sq ft — must be within the existing primary dwelling or accessory structure.

Permit Fees

ADU Permit Fees in Los Angeles: Plan check fee: Varies. Building permit fee: Varies. Impact fees: None. School fees: None or N/A. Total estimated permit cost: Varies.

Permit Timeline

Los Angeles ADU Permit Timeline: The permitting agency shall either approve or deny the application to create or serve an accessory dwelling unit within 60 days from the date the permitting agency receives a completed application if there is an existing single-family or multifamily dwelling on the lot. Note: LADBS ADU Express service targets 2-4 weeks for plan check; construction typically 4-12 months (operational, not codified). Apply through the LA Department of Building and Safety (LADBS) online permit portal. Phone: (213) 482-0000.

Setback Requirements

ADU Setback Requirements in Los Angeles: Front setback: follows zone standard. Side setback: no minimum. Rear setback: no minimum.

Parking Requirements

Parking Requirements: No additional parking required for ADUs within one-half mile of public transit, within architecturally and historically significant historic districts, or when garage/carport is converted to ADU. Per California Gov Code §66322(a)(1).

Restrictions & Requirements

• •ADU must comply with objective zoning and design standards
• •Setback violation structures may be rebuilt as ADU in same footprint per state law
• •ADU cannot be sold separately from primary dwelling (unless Urban Lot Split per Gov Code §66411.7 applies)
• •Short-term rental of ADU (less than 30 days) requires Home Sharing registration
• •ADU must have permanent foundation — no recreational vehicles or manufactured homes without permanent foundation

How Many ADUs Are Allowed?

Number of ADUs Allowed in Los Angeles: Single-family lots: 1 ADU + 1 JADU per single-family lot. Multifamily properties: Up to 25% of existing units (minimum 2) as detached ADUs; 1 ADU per existing unit for internal conversions. Per Gov Code §66323(a)(3): multifamily properties may convert 25% of existing units to ADUs. One detached ADU permitted per multifamily lot per Gov Code §66323(a)(4). Urban Lot Split (Gov Code §66411.7) permits 2 units per parcel after qualifying lot split.

Single-Family Lots

1 ADU + 1 JADU per single-family lot

Multifamily Properties

Up to 25% of existing units (minimum 2) as detached ADUs; 1 ADU per existing unit for internal conversions

Statewide Preemption

State Law & Preemption

Historic District Considerations

Frequently Asked Questions