Sonoma, CA Accessory Structures: Garage Conversions (2026)

This rule lives inside Chapter 19.41, Sonoma's ordinance implementing state law SB 9 (Government Code Sections 65852.21 and 66411.7) for two-unit residential development and urban lot splits; it governs garage conversions specifically in that two-unit context rather than accessory structures generally. SMC 19.41.150(A)(8) sets the baseline: one covered or uncovered off-street parking space is required per dwelling unit in a two-unit project. Subsection (8)(c) bars tandem parking, requiring each unit to have its own space reachable without crossing the other unit's space. Subsection (8)(d) is the garage-conversion trigger: when an existing garage, carport, or other covered parking structure is converted or demolished to make way for a new unit, the property owner must provide at least one replacement parking space, which does not have to be covered, for each unit, unless the project is exempt from parking requirements altogether.

That exemption matters because SMC 19.41.150(A)(8)(a)(i) waives parking entirely for a parcel within a half-mile walk of a high-quality transit corridor or major transit stop, or within one block of a designated car-share space, tracking the state parking exemptions built into SB 9 and the Density Bonus Law. Because Chapter 19.41 implements a state ministerial-approval mandate, the city cannot use its own objective standards, including this parking rule, to physically preclude construction of up to two 800-square-foot units on a qualifying parcel; SMC 19.41.150(A) says any such standard is waived to the extent it would block that minimum development.