How large can an ADU be in Los Angeles?

A detached ADU can be up to 1,200 square feet. An attached ADU can be up to 1,200 square feet or 50% of the existing primary dwelling's floor area, whichever is less. A Junior ADU (JADU) can be up to 500 square feet.

Do I need to provide parking for an ADU in Los Angeles?

No. Los Angeles does not require additional parking for ADUs. The city applies the state transit-proximity parking exemption citywide.

How long does it take to get an ADU permit in Los Angeles?

Under California state law, the city must approve or deny a complete ADU application within 60 days. Actual timelines may vary depending on plan check corrections, but the review is ministerial (non-discretionary).

ADU Rules and Regulations in Los Angeles

Los Angeles permits Accessory Dwelling Units (ADUs) and Junior ADUs (JADUs) on most residentially zoned properties under both California state law and the Los Angeles Municipal Code (LAMC Section 12.22 A.31).

What You Can Build

Detached ADU: A standalone structure up to 1,200 square feet, up to 16 feet tall, with 4-foot rear and side setbacks.
Attached ADU: An addition to the primary dwelling up to 1,200 square feet or 50% of the primary dwelling's floor area, whichever is less.
Junior ADU (JADU): A unit up to 500 square feet converted from existing space within the primary dwelling (must include a cooking facility and separate entrance).
Garage Conversion: An existing garage can be converted to an ADU regardless of size, with no replacement parking required.

On a single-family lot, you may build one ADU plus one JADU. On multi-family lots, additional ADUs may be permitted.

Size Limits

ADU Type	Maximum Size
Detached ADU	1,200 sq ft
Attached ADU	1,200 sq ft or 50% of primary dwelling
Junior ADU (JADU)	500 sq ft
Garage Conversion	No size limit (existing footprint)

Setbacks

Front setback: Must comply with base zone (typically 20 ft in R1)
Side setback: 4 feet for detached ADU
Rear setback: 4 feet for detached ADU
Conversion exception: ADUs converted from existing legal structures maintain existing setbacks, even if nonconforming

Height

Detached ADU: 16 feet maximum
Attached ADU: Must not exceed the height of the primary dwelling
Near transit: Up to 18 feet may be allowed for detached ADUs within half a mile of a major transit stop

Parking

No additional parking is required for ADUs in Los Angeles. The city applies the state parking exemption citywide. If an existing garage is converted or demolished to build an ADU, the displaced parking spaces do not need to be replaced.

Permit Process

Pre-application: Review your property's zoning and constraints on ZIMAS
Plan preparation: Prepare architectural plans meeting building code requirements
Submit application: File with the LA Department of Building and Safety (LADBS)
Plan check: Ministerial review within 60 days of a complete application
Corrections: Address any plan check comments and resubmit
Permit issuance: Receive building permit and begin construction
Inspections: Schedule required inspections during construction
Final approval: Receive Certificate of Occupancy upon passing final inspection

Fees and Costs

Permit fees vary by project scope but typically range from $3,000 to $15,000
ADUs under 750 square feet are exempt from development impact fees
School fees and other impact fees may be waived or reduced for smaller ADUs
Utility connection fees may apply for detached ADUs requiring new service connections

Los Angeles ADU Rules & Regulations