Tustin, CA Accessory Structures: ADU Rules (2026)

In December 2021, the Tustin City Council adopted Ordinance No. 1517, amending Tustin City Code Section 9279 to bring the city into compliance with California state ADU law (Gov. Code 66310 et seq.). An ADU provides complete independent living facilities (living, sleeping, eating, cooking, sanitation) on the same parcel as a single-family or multi-family dwelling. Tustin recognizes three types: attached, converted (within existing permitted space), and detached. Per the city, ADUs range from a 220-square-foot minimum up to 850 square feet for a studio or one-bedroom unit, and up to 1,200 square feet for a unit with two or more bedrooms. A Junior ADU (JADU) is no more than 500 square feet and must be contained entirely within the walls of a proposed or existing single-family residence, including an attached garage. Detached ADUs are generally allowed at least one story and 16 feet in height, with a 4-foot setback from rear and interior side property lines, consistent with state law. Required ADU parking may not exceed one space per bedroom, and parking is exempted when the unit is within one-half mile walking distance of public transit. Because much of Tustin's Old Town lies within the Cultural Resources District, an ADU or new accessory structure there is also subject to Design Review and a Certificate of Appropriateness. Confirm specifics with the Tustin Community Development Department at (714) 573-3140.