Tustin, CA Accessory Structures: Garage Conversions (2026)

Tustin regulates garage conversions through the parking table in Tustin City Code Section 9263(g), Table 1, Off-Street Parking Requirements by Land Use, read together with the ADU ordinance at Section 9279. The parking table states plainly that off-street parking spaces are not required to be replaced when an existing garage, carport, or covered parking structure is demolished in conjunction with building an ADU or is itself converted into an ADU, so a homeowner who turns a two-car garage into a backyard unit does not have to find room elsewhere on the lot for two replacement spaces.

Section 9279(D)(2)(a) confirms the conversion is allowed in the first place: an ADU can be attached to, or located within, the primary dwelling, including attached garages, storage areas, or similar uses. A converted ADU also gets relief from the yard setbacks that apply to new construction: Section 9279(D)(6)(c) waives setbacks for converted ADUs as long as the existing structure's side and rear setbacks already satisfy fire and safety codes. Junior ADUs are treated differently on parking. The same Table 1 states that no additional off-street parking is required for a JADU beyond what the primary dwelling already needed, but when an existing attached garage is converted into a JADU specifically, any required off-street parking spaces eliminated by that conversion must be replaced elsewhere on the lot.

In practice that means converting a detached garage into an ADU carries no parking replacement obligation, while converting an attached garage into a JADU does, because the attached garage was originally counted toward the primary house's own parking requirement.