Garage Conversions: Altadena vs El Monte
How do garage conversions rules compare between Altadena, CA and El Monte, CA?
Altadena and El Monte 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 →El Monte, CA
Los Angeles County
El Monte permits garage conversions to ADUs under California Government Code and Municipal Code Chapter 17.110. Conversions require building permits and must meet habitability standards. No replacement parking is required per state law.
View full El Monte rules →Key Facts Comparison
| Fact | Altadena | El Monte |
|---|---|---|
| Governing Code | LA County Code §22.140.640 | - |
| Replacement Parking | Not required | Not required (state law) |
| Existing Setbacks | Grandfathered | - |
| Fire-Zone Construction | Chapter 7A in WUI hillside | - |
| Permit Required | Yes — LA County building | - |
| Code Section | - | EMMC Ch. 17.110 |
| State Law | - | CA Gov. Code §66314-66339 |
| JADU Max | - | 500 sq ft from existing space |
| Permit | - | Building permit required |
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.
El Monte FAQ
Can I convert my garage to a living space in El Monte?
Yes, through the ADU or JADU permitting process under Chapter 17.110. A building permit is required and the space must meet all habitability standards.
Do I need to replace parking if I convert my garage?
No. Under California state law, the city may not require replacement parking for a garage converted to an ADU.
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