Santee, CA Accessory Structures: Garage Conversions (2026)

Two tracks in Section 13.10.045(F)(1) cover garage conversions, and both are reviewed with only a building permit, no conditional use permit, no development review hearing. On a single-family lot, subsection (F)(1)(a) allows an ADU "within the existing space of an accessory structure, plus up to 150 additional square feet if the expansion is limited to accommodating ingress and egress," alongside the JADU allowance for space inside the house itself. A detached garage that already sits on the lot qualifies as that accessory structure.

Multifamily properties get a dedicated garage-conversion path under subsection (F)(1)(c). The code allows "one or more ADUs within portions of existing multifamily dwelling structures that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages," as long as each converted unit meets state building standards for dwellings. The cap is explicit: at least one converted ADU is always allowed, and up to 25% of the existing multifamily dwelling units on the property may each gain a converted ADU under this paragraph.

Subsection (F)(1)(a)(iii) still requires side and rear setbacks sufficient for fire and safety as dictated by the applicable building and fire codes, and subsection (E)(6) lets a demolition permit for a detached garage being replaced with an ADU move through review alongside the ADU application itself, rather than as a separate approval. Development Services must act on a complete garage-conversion application within 60 days under subsection (E)(3).