Garage Conversions: Irvine vs Midway City
How do garage conversions rules compare between Irvine, CA and Midway City, CA?
Midway City has fewer restrictions than Irvine.
Irvine, CA
Orange County
Garage conversions to ADUs in Irvine are permitted by right under California Government Code Section 65852.2 with no replacement parking required. Non-ADU conversions must maintain the required off-street parking for the zoning district.
View full Irvine rules →Midway City, CA
Orange County
Unincorporated Orange County allows the conversion of an existing garage, carport, or accessory structure into an accessory dwelling unit (ADU) under Section 7-9-90 of the Codified Ordinances and California Government Code Section 65852.2. A garage-conversion ADU may be the size of the converted structure plus up to 150 square feet for ingress/egress, processed ministerially, and the parking space lost in the conversion does not need to be replaced.
View full Midway City rules →Key Facts Comparison
| Fact | Irvine | Midway City |
|---|---|---|
| ADU Conversion | Permitted by right, no replacement parking | - |
| Non-ADU Conversion | Must maintain off-street parking | - |
| Permit Required | Building permit for all conversions | - |
| Min Ceiling Height | 7 ft for habitable space | - |
| Contact | Planning (949) 724-6308 | - |
| Authority | - | OC Codified Ord. Sec. 7-9-90 |
| State Law | - | Cal. Gov't Code 65852.2 / 65852.22 |
| Conversion Size | - | Existing footprint + up to 150 sq ft ingress/egress |
| Max Size | - | 1,200 sq ft (ADU); 500 sq ft (JADU) |
| Parking Replacement | - | Not required (Sec. 7-9-90(d)(3)) |
| Permit Process | - | Ministerial (60-day review) |
| Short-Term Rental | - | Prohibited (Sec. 7-9-90(c)(5)) |
| Permit Authority | - | OC Public Works Development Services |
Highlighted rows indicate differences between cities.
Irvine FAQ
Can I convert my garage to an ADU without adding parking?
Yes. Under California state ADU law, garage conversions to ADUs do not require replacement parking.
What building code requirements apply to a garage conversion?
The converted space must meet CBC standards including minimum 7-foot ceiling height, insulation, ventilation, egress windows, and smoke/CO detectors.
Midway City FAQ
Do I have to replace the parking space if I convert my garage to an ADU in unincorporated Orange County?
No. Section 7-9-90(d)(3) of the Orange County Codified Ordinances expressly states that no replacement of removed parking spaces is required when an existing garage, carport, or covered parking garage is converted to an ADU or removed to accommodate ADU construction. This mirrors California Government Code 65852.2 and is one of the strongest permissive ADU rules in the state.
How big can my garage-conversion ADU be?
Section 7-9-90(a)(2) caps a conversion ADU at the square footage of the converted structure, up to 1,200 square feet. Section 7-9-90(c)(1) separately allows an expansion of up to 150 square feet beyond the existing dimensions for ingress/egress (which counts toward the maximum). A junior ADU is capped at 500 square feet under Section 7-9-90(a)(3) and Government Code 65852.22.
Can I rent out my converted garage on Airbnb?
No. Section 7-9-90(c)(5) prohibits any ADU or JADU from being used as a short-term rental of less than 30 days. The unit may be used as a long-term rental of more than 30 days. Short-term-rental use can support administrative action against the ADU and code-enforcement penalties.
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