Garage Conversions: Midway City vs Mission Viejo

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.

Can I convert my garage to a living space?

Yes, garage conversions to ADUs are allowed under California state law. You need a building permit and must meet habitable space requirements for insulation, egress, and ventilation.

Do I need to add parking if I convert my garage?

No, California law prohibits cities from requiring replacement parking when a garage is converted to an ADU. This applies even if the conversion eliminates all covered parking.

Can my HOA block a garage conversion?

Under California Civil Code Section 4751, HOAs cannot unreasonably restrict ADU conversions. They may set reasonable design standards but cannot effectively prohibit the conversion.