ADU rules in the City of Los Angeles
The key facts first, then what we've learned building there.
The snapshot
Checked October 2026. We re-check every lot against the current code.
City of Los Angeles
| Rule | Answer |
|---|---|
| Detached ADU size | Up to 1,200 sq ft |
| Setbacks | 4 ft side and rear |
| Height | 16 ft; 18 ft near transit; 25 ft attached |
| Two stories | Attached or over a garage, often; a detached ADU at 16 to 18 ft is usually one story. We check your zone. |
| Pre-approved plans | Yes, Standard Plan Program |
| Hillside / fire zone | Extra rules; we check case by case |
| SB 1211 apartment ADUs | Yes |
| Building department | LADBS |
What's different here
Very High Fire Hazard Severity Zones and hillside streets bring sprinkler, access and road-width checks. Some lots can't take a detached ADU; most can take a conversion.
Many older LA buildings are under the RSO. New ADUs follow their own rules; we flag it before design.
LADBS keeps a Standard Plan Program list of pre-checked ADU designs.
Where in LA we build
These neighborhoods are all in the City of Los Angeles, so these rules apply.
- Woodland Hills
- Tarzana
- Encino
- Sherman Oaks
- Brentwood
- Westwood
- Hollywood
- Koreatown
- Mid-Wilshire
- Downtown LA
- South LA
- Venice
- San Pedro
- Wilmington
- Harbor City
What applies here
Since January 2025, California lets an existing apartment property add detached ADUs, one for every existing unit up to eight, plus conversions of garages and storage.
Learn more
SB 9 lets a single-family lot be split in two, with up to two homes on each.
Learn more
Cities must now keep a set of pre-approved ADU plans.
Learn morePlans that fit
Ready-drawn plans we adapt to your lot and your city.
Ask about your address
We check the lot against these rules and tell you what fits.