State law permits ADUs up to 1,200 sqft for detached units. 6,000–10,000+ sqft for standard residential neighborhoods. Orange Park Acres lots range from 0.5 to 5+ acres. No minimum lot size required by state law to build an ADU.
Up to 16 feet for detached ADUs. Up to 25 feet for attached ADUs in qualifying residential zones.
4-foot minimum from rear and side property lines for new detached ADUs. Conversions of existing structures are exempt from setback requirements.
One parking space per ADU may be required. Exempt if within 0.5 miles of public transit, within one block of a car-share vehicle, or if the ADU is a conversion of existing space.
No owner-occupancy requirement for ADUs (made permanent by AB 976 in 2025).
Estimated cost $250K–$400K. Permit fees $5K–$12K. Impact fees: Waived under 750 sqft.
The City of Orange is one of the most architecturally distinctive communities in Orange County, anchored by the Old Towne Historic District — one of the largest National Register-listed historic districts in California. Home to Chapman University and its 10,000+ students, Orange features established neighborhoods with mature landscaping and generous lot sizes. Orange Park Acres, a unique semi-rural enclave within the city, offers half-acre to multi-acre equestrian properties ideal for large detached ADUs. The city's central OC location provides easy access to the 55, 57, and 22 freeways, connecting residents to employment centers in Irvine, Anaheim, and Santa Ana.