Attached ADU — Los Angeles
An Attached ADU is an Accessory Dwelling Unit that shares at least one wall with the primary dwelling unit. It may be an addition to the existing home or created by converting an existing attached garage or interior space.
Site Plan — Typical Configuration
Development Standards — City of Los Angeles
| Standard | Requirement | Notes |
|---|---|---|
| Maximum Size | 1,200 sq ft OR 50% of existing living area | Whichever is less; 850 sq ft if no bedrooms, 1,000 sq ft for 1+ bedrooms (state minimum) |
| Height Limit | Same as primary structure (typically 28–36 ft) | Cannot exceed height of main dwelling |
| Side/Rear Setbacks | 4 ft minimum | State law floor; local may be more restrictive |
| Front Setback | Must match existing primary structure setback | — |
| Lot Coverage | Per zone (typically 40–50%) | ADU floor area counts toward lot coverage |
| Parking | No additional parking required | Applies when within ½ mile of transit or in certain zones |
| Separate Entry | Required | Must have independent exterior access |
| Kitchen/Bath | Full kitchen and bathroom required | Distinguishes ADU from JADU |
| Fire Sprinklers | Required if primary structure has them | Also required in certain high-fire zones |
State ADU Standards (Gov. Code § 65852.2)
| Standard | State Minimum |
|---|---|
| Minimum Size Allowed | Studio/1-bed: 850 sq ft | 2+ bed: 1,000 sq ft |
| Setbacks — New Construction | 4 ft side and rear |
| Setbacks — Conversions | 0 ft (no setback required for conversion of existing structure) |
| Owner-Occupancy | Not required (until Jan 1, 2025 moratorium lapsed) |
| Rental Term | 30-day minimum rental period |
| Utility Connections | City may require separate connections; fees shall be proportionate |
Conversion of Existing Space
Converting an attached garage, bonus room, or other existing space into an ADU has streamlined permitting and reduced setback requirements:
| Conversion Type | Key Benefit |
|---|---|
| Attached garage conversion | No replacement parking required; no setback if within existing footprint |
| Interior conversion (bonus room, basement) | Typically administrative permit only; no discretionary review |
| Expansion of existing space | Expansion portion subject to 4 ft setback; existing portion exempt |
Disclaimer: This guide is for informational purposes only and reflects regulations as of early 2026. Always verify current requirements with LADBS prior to design or construction.