ADU Rules: Castaic vs Pasadena
How do adu rules rules compare between Castaic, CA and Pasadena, CA?
Castaic and Pasadena have similar restriction levels.
Castaic, CA
Los Angeles County
Castaic 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. Single-family lots may add one ADU plus one JADU; multifamily lots may add up to two detached new-construction ADUs plus conversion ADUs created in non-livable existing space.
View full Castaic rules →Pasadena, CA
Los Angeles County
Pasadena allows ADUs under California state law (AB 68, SB 13, AB 881). Both attached and detached ADUs are permitted. The city has streamlined its permitting process to comply with state mandates.
View full Pasadena rules →Key Facts Comparison
| Fact | Castaic | Pasadena |
|---|---|---|
| Governing Code | LA County Code §22.140.640 | - |
| Single-Family | 1 ADU + 1 JADU per lot | - |
| Multifamily Detached | Up to 2 new (20 ft max) | - |
| WUI Fire Zone | Chapter 7A applies | - |
| Side/Rear Setback | 4 ft (new construction) | - |
| Detached ADU | - | Up to 1,200 sq ft |
| Junior ADU | - | Up to 500 sq ft |
| Setback | - | 4 feet for detached ADU |
| Parking | - | None required near transit |
Highlighted rows indicate differences between cities.
Castaic FAQ
Who regulates ADUs in Castaic?
Castaic is unincorporated, so LA County Regional Planning regulates ADUs under LA County Code Title 22 §22.140.640, not a separate city ordinance.
Are there fire-zone restrictions on Castaic ADUs?
Yes. Portions of Castaic are in LA County's Very High Fire Hazard Severity Zone, so ADUs must meet Chapter 7A wildland-urban interface ignition-resistant construction standards and LA County Fire Code §325 brush clearance.
Can a Castaic 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).
Pasadena FAQ
Can I build an ADU in Pasadena?
Yes. California law requires cities to allow ADUs. Detached units up to 1,200 sq ft and junior ADUs up to 500 sq ft are permitted.
Do I need to live on the property?
No. California state law removed owner occupancy requirements for ADUs.
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