Accessory Structures in Sonoma, CA (2026)
9 verified accessory structures rules for Sonoma, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Sonoma allows ADUs and JADUs in all residential zones (R-HS, R-R, R-L, R-S, R-M, R-H, R-O, R-P) under SMC Chapter 19.45, consistent with Cal. Gov. Code 65852.2. Detached ADUs are capped at 850 sq ft (or up to 1,200 sq ft with proportional limits) with a 4-foot side/rear setback and 16-foot height for single story.
ADU Development Standards (SMC Ch. 19.45)
Some RestrictionsADU Permits
All ADUs and JADUs require a building permit from the City of Sonoma Planning and Community Services Department, processed ministerially under state law (Cal. Gov. Code 65852.2(b)) within 60 days of a complete application. No discretionary CUP or public hearing is required.
ADU Building Permit Process (SMC 19.45.040)
Some RestrictionsADU Impact Fees
Per Cal. Gov. Code 65852.2(f) and 66311.5, ADUs under 750 sq ft pay NO impact fees in Sonoma. ADUs 750 sq ft or larger pay impact fees proportionate to the ratio of ADU square footage to the primary dwelling's square footage, collected at final inspection or certificate of occupancy.
ADU Impact Fees - State Waiver Under 750 sq ft (SMC 19.45.040)
Few RestrictionsADU Owner Occupancy
JADUs require owner-occupancy of the parcel (either the main house or the JADU). New ADUs permitted on or after January 1, 2020 are exempt from owner-occupancy per Cal. Gov. Code 65852.2(a)(6); pre-2020 ADUs remain subject to the rule in effect at permitting.
ADU/JADU Owner-Occupancy Rules (SMC 19.45.030)
Some RestrictionsADU Rental Restrictions
Sonoma prohibits renting any ADU or JADU for terms shorter than 30 days (no short-term/vacation rentals). Properties with an attached JADU are categorically ineligible for vacation rental use.
ADU Rental Restrictions - 30-Day Minimum (SMC 19.45.030)
Heavy RestrictionsShed Rules
Detached storage sheds 120 sq ft or smaller and not over 8 ft tall may sit at the side or rear property line without a building permit; anything larger triggers SMC 19.50.080 standards and a Permit Sonoma building permit.
Storage Shed Rules — City of Sonoma
Some RestrictionsGarage Conversions
The City permits converting an existing garage into an ADU under SMC 19.45.040 with no replacement parking required; state law (Gov. Code §66323) and the City waive parking when the ADU is within ½ mile of transit or in the historic district.
Garage Conversion Rules — City of Sonoma
Few RestrictionsCarport Rules
Carports are listed accessory uses under SMC 19.50.080; detached carports must follow the 15-ft height cap and are barred from front and street-side setbacks, while attached carports must meet the main dwelling's setback and height standards.
Carport Rules — City of Sonoma
Some RestrictionsTiny Homes
The City of Sonoma has not adopted the County's movable-tiny-home (THOW) program — within city limits a tiny home is only legal as a permanent-foundation ADU built to the California Building Code under SMC Chapter 19.45.
Tiny Home Rules — City of Sonoma
Heavy RestrictionsLooking for Sonoma County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Sonoma city rules.
Accessory Structures in Sonoma County →