Garage Conversions: Altadena vs Pasadena
How do garage conversions rules compare between Altadena, CA and Pasadena, CA?
Altadena and Pasadena have similar restriction levels.
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 →Pasadena, CA
Los Angeles County
Garage conversions to ADUs in Pasadena are streamlined under California law. Converting existing garage space to living quarters does not require replacement parking. Building permits are required.
View full Pasadena rules →Key Facts Comparison
| Fact | Altadena | Pasadena |
|---|---|---|
| Governing Code | LA County Code §22.140.640 | - |
| Replacement Parking | Not required | Not required under CA law |
| Existing Setbacks | Grandfathered | - |
| Fire-Zone Construction | Chapter 7A in WUI hillside | - |
| Permit Required | Yes — LA County building | - |
| Permit | - | Building permit required |
| Building Code | - | Must meet habitable space standards |
| Setbacks | - | Existing nonconformities grandfathered |
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.
Pasadena FAQ
Can I convert my garage in Pasadena?
Yes. California law streamlines garage-to-ADU conversions. No replacement parking is required. A building permit is needed.
Do I need to provide replacement parking?
No. California law waives replacement parking requirements for garage-to-ADU conversions.
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