Garage Conversions: Downey vs Topanga
How do garage conversions rules compare between Downey, CA and Topanga, CA?
Downey and Topanga have similar restriction levels.
Downey, CA
Los Angeles County
Downey allows garage conversions to ADUs under state law and DMC §9414.08. Replacement parking is not required. No minimum setback for conversions. Height limits don't apply to conversions. Driveway max 20 feet wide.
View full Downey rules →Topanga, CA
Los Angeles County
Garage conversions to ADUs in unincorporated Topanga are governed by LA County Code Title 22 §22.140.640 and California Government Code §65852.2. No replacement parking is required when a garage is converted to an ADU, and existing setbacks are preserved. A Coastal Development Permit applies in the Santa Monica Mountains Local Coastal Program area.
View full Topanga rules →Key Facts Comparison
| Fact | Downey | Topanga |
|---|---|---|
| Replacement Parking | Not required | Not required |
| Setback | None for conversions | - |
| Driveway Max | 20 ft wide | - |
| Code Section | DMC §9414.08; GC §65852.2 | - |
| Governing Code | - | LA County Code §22.140.640 |
| Existing Setbacks | - | Grandfathered |
| Coastal Permit | - | Required in SMM LCP |
| Permit Required | - | Yes — LA County building |
Highlighted rows indicate differences between cities.
Downey FAQ
Can I convert my garage into living space in Downey?
Downey allows garage conversions to ADUs under state law and DMC §9414.08. Replacement parking is not required. No minimum setback for conversions. Height limits don't apply to conversions. Driveway max 20 feet wide.
What permits do I need for a garage conversion in Downey?
Replacement Parking: Not required. Setback: None for conversions. Driveway Max: 20 ft wide. Code Section: DMC §9414.08; GC §65852.2.
Topanga FAQ
Do I need to add parking if I convert my Topanga garage to an ADU?
No. Cal. Gov Code §65852.2 and LA County Code §22.140.640 prohibit the county from requiring replacement parking when a garage is converted to an ADU.
Do I still need a Coastal Development Permit for a garage conversion?
Yes, typically. Most Topanga properties fall within the certified Santa Monica Mountains LCP, so a CDP is required in addition to the building permit unless a categorical exclusion applies.
Who issues the permit for a Topanga garage conversion?
LA County Public Works (Building & Safety) issues the building permit; LA County Regional Planning processes the ministerial ADU review and any Coastal Development Permit.
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