Garage Conversions: Altadena vs Glendale
How do garage conversions rules compare between Altadena, CA and Glendale, CA?
Glendale has fewer restrictions than Altadena.
Altadena, CA
Los Angeles County
Garage conversions to ADUs in unincorporated Altadena are governed by LA County Code Title 22 §22.140.640 and California Government Code §65852.2. No replacement parking is required when an existing garage is converted, and existing setbacks are grandfathered. Properties in Very High Fire Hazard Severity Zones also trigger Chapter 7A wildland-urban interface standards.
View full Altadena rules →Glendale, CA
Los Angeles County
Glendale allows garage-to-ADU and garage-to-JADU conversions under GMC §30.34.080, consistent with California Government Code §65852.2. No replacement parking is required when an existing garage is converted to an ADU, and the existing setbacks are preserved for the conversion footprint.
View full Glendale rules →Key Facts Comparison
| Fact | Altadena | Glendale |
|---|---|---|
| Governing Code | LA County Code §22.140.640 | - |
| Replacement Parking | Not required | Not required |
| Existing Setbacks | Grandfathered | Preserved for conversion |
| Fire-Zone Construction | Chapter 7A in WUI hillside | - |
| Permit Required | Yes — LA County building | Yes — building permit |
| Code Section | - | GMC §30.34.080; Cal. Gov Code §65852.2 |
| Multifamily Conversion | - | Up to 25% of existing units |
Highlighted rows indicate differences between cities.
Altadena FAQ
Do I need replacement parking if I convert my Altadena 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.
Are fire-resistant materials required for an Altadena garage conversion?
Yes, where the property is in a Very High Fire Hazard Severity Zone. Chapter 7A of the California Building Code requires ignition-resistant siding, eaves, vents, windows, and roofing in Altadena's hillside WUI areas.
Who handles the Altadena garage conversion permit?
LA County Public Works (Building & Safety) issues the building permit and LA County Regional Planning handles the ministerial ADU planning review under §22.140.640.
Glendale FAQ
Do I need to replace my parking if I convert my Glendale garage to an ADU?
No. Cal. Gov Code §65852.2 and GMC §30.34.080 prohibit Glendale from requiring replacement parking when an existing garage is converted to an ADU.
Can my Glendale multifamily building add conversion ADUs?
Yes. Under GMC §30.34.080, conversion ADUs may be created in non-livable space within an existing multifamily building up to 25% of the existing unit count.
Do I still need a permit to convert a Glendale garage?
Yes. A building permit from Glendale Community Development is required for any change of use from garage to habitable space, though the planning review is ministerial under §30.34.080.
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