ADU Rules: Compton vs Topanga
How do adu rules rules compare between Compton, CA and Topanga, CA?
Compton and Topanga have similar restriction levels.
Compton, CA
Los Angeles County
Compton adopted ADU Ordinance No. 2341 on December 28, 2021. Both attached and detached ADUs up to 1,200 sq ft and JADUs up to 500 sq ft are permitted in residential zones with no minimum lot size.
View full Compton rules →Topanga, CA
Los Angeles County
Topanga is an unincorporated CDP in Los Angeles County governed by LA County Code Title 22 §22.140.640 (Accessory Dwelling Units and Junior Accessory Dwelling Units), most recently amended April 2024. Detached ADUs are capped at 1,200 sq ft; multifamily-lot ADUs have no maximum size under county rules. Topanga lies within the Santa Monica Mountains Coastal Zone, so a Coastal Development Permit also applies.
View full Topanga rules →Key Facts Comparison
| Fact | Compton | Topanga |
|---|---|---|
| Max Size (Detached) | 1,200 sq ft | - |
| JADU Max | 500 sq ft | - |
| Setback | 4 ft side/rear | - |
| Ordinance | No. 2341 (Dec 28, 2021) | - |
| Governing Code | - | LA County Code §22.140.640 |
| Single-Family | - | 1 ADU + 1 JADU per lot |
| Multifamily Detached | - | Up to 2 new + conversion ADUs |
| Coastal Permit | - | Required (Santa Monica Mtns LCP) |
| Side/Rear Setback | - | 4 ft (new construction) |
Highlighted rows indicate differences between cities.
Compton FAQ
Can I build an ADU on my property in Compton?
Compton adopted ADU Ordinance No. 2341 on December 28, 2021. Both attached and detached ADUs up to 1,200 sq ft and JADUs up to 500 sq ft are permitted in residential zones with no minimum lot size.
What are the size limits for an accessory dwelling unit in Compton?
Max Size (Detached): 1,200 sq ft. JADU Max: 500 sq ft. Setback: 4 ft side/rear. Ordinance: No. 2341 (Dec 28, 2021).
Topanga FAQ
Who regulates ADUs in Topanga?
Topanga is unincorporated, so LA County Department of Regional Planning regulates ADUs under LA County Code Title 22 §22.140.640, not a separate city ordinance.
Do I need a Coastal Development Permit for a Topanga ADU?
Yes. Topanga falls within the certified Santa Monica Mountains Local Coastal Program, so most ADU construction requires a Coastal Development Permit in addition to the building permit.
Can a Topanga multifamily lot add detached ADUs?
Yes. Under LA County Code §22.140.640, multifamily lots may add up to two detached new-construction ADUs plus conversion ADUs within non-livable space (up to 25% of existing units).
Compare other topics
See how Compton and Topanga compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool