Accessory Structures in Santa Rosa, CA (2026)
7 verified accessory structures rules for Santa Rosa, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Santa Rosa allows one ADU plus one JADU on single-family lots under Zoning Code Section 20-42.130, adopted by urgency Ordinance on March 3, 2020 to align with California Government Code Sections 65852.2 and 65852.22. Detached ADUs are capped at 1,200 sq ft with 4-ft side/rear setbacks and a 16-ft (one-story) or 27-ft (two-story) height limit; JADUs are capped at 500 sq ft and must sit entirely within the existing single-family dwelling walls.
Santa Rosa ADU & JADU Ordinance (Sec. 20-42.130)
Some RestrictionsSanta Rosa City Code, Title 20 (Zoning), Section 20-42.130 (Accessory dwelling units), adopted by urgency Ordinance, March 3, 2020 (File REZ20-001)
20-42.130 Accessory dwelling units. Accessory dwelling units shall comply with the requirements of this Section, where allowed by Division 2 (Zoning Districts and Allowable Land Uses). A. Purpose. The provisions of this Section are intended to set standards, in compliance with California Government Code Sections 65852.2, and 65852.22, for the development of accessory dwelling units so as to inc...
ADU Impact Fees
Santa Rosa exempts small accessory dwelling units from utility connection fees entirely: units 750 square feet or smaller, and any internal conversion, pay no new connection fee or capacity charge. Any larger ADU still pays impact fees, but only in proportion to its square footage against the primary dwelling's.
Santa Rosa ADU Impact Fees Scale with Size
Some RestrictionsSanta Rosa City Code § 20-42.130(D)(3)
3. Utility connections and fees. a. Except as provided in Subsection D.3.b, a separate new utility connection and payment of a connection fee or capacity charge pursuant to State law and City fee schedule will be required for any new accessory dwelling unit. b. No new or separate utility connection or related connection fee or capacity charge will be required for accessory dwelling units that a...
ADU Owner Occupancy
Santa Rosa cannot require an owner to live on-site as a condition of building or keeping an accessory dwelling unit, at least before January 1, 2025. A junior accessory dwelling unit is different: the City's recorded deed-restriction requirement ties its legality to continued owner-occupancy of either the JADU or the primary home.
No Owner-Occupancy Required for Santa Rosa ADUs
Light RestrictionsSanta Rosa City Code § 20-42.130(E)(17), (G)(2)
17. Ownership. The Department shall not impose an owner-occupant requirement on an accessory dwelling unit before January 1, 2025. [...] G. Deed restrictions. Prior to occupancy of a junior accessory dwelling unit that shares sanitation facilities with the single-family dwelling on-site, the property owner shall file with the County Recorder a deed restriction containing a reference to the deed...
ADU Rental Restrictions
An accessory dwelling unit built under Santa Rosa's ADU ordinance cannot be rented out for stays shorter than 30 days. The identical 30-day minimum applies to junior accessory dwelling units, closing off vacation-rental and short-term-rental use of both unit types citywide, regardless of zoning district or lot size.
Santa Rosa ADUs Barred from Short-Term Rental
Significant RestrictionsSanta Rosa City Code § 20-42.130(B)(4)
B. General requirements. An accessory dwelling unit: 1. May be located on any lot that allows a single-family or multifamily residential use and includes a proposed or existing dwelling. 2. Is not subject to the density requirements of the General Plan, but shall otherwise be consistent with the General Plan text and diagrams. [...] 4. Shall not be used for rentals with terms of less than 30 da...
Shed & Carport Rules
Santa Rosa requires a building permit for any accessory structure over 120 square feet of floor area, per the city's Accessory Structure Requirements Policy (Policy No. 2.5.3, effective June 2, 2005, revised July 2011) which implements California Building Code Section 1808 and Santa Rosa Zoning Code Section 20-42.030. Sheds 120 sq ft or smaller are exempt from a structural permit but cannot be used as habitable or conditioned space, and any electrical or plumbing installation requires a separate permit.
Shed & Accessory Structure Permit Rules (CBC 1808 / 20-42.030)
Some RestrictionsSanta Rosa Community Development - Building and Code Compliance, Accessory Structure Requirements, Policy No. 2.5.3, Effective June 2, 2005, Revised July 2011 (implementing CBC 1808 and Santa Rosa City Code Sec. 20-42.030)
PURPOSE: The following policy clarifies the requirement for foundations under accessory structures. Previous code (2001 CBC) allowed a one story wood or metal frame building not used for human occupancy and not over 400 square feet in floor area may be constructed with walls supported on a wood foundation plate when approved by the building official. This exception was removed from the CBC in 2...
Garage Conversions
Santa Rosa permits garage-to-ADU conversions ministerially under Zoning Code Section 20-42.130 with no replacement parking required and no setback required for existing legally constructed garages converted to an ADU with independent exterior access. Conversion to non-habitable storage requires a standard building permit, while conversion to habitable space (ADU or JADU) follows the city's 2020 ADU ordinance and California Government Code Sections 65852.2 and 65852.22.
Garage-to-ADU Conversions (Sec. 20-42.130 E.2.c / E.10.h)
Some RestrictionsSanta Rosa City Code, Title 20 (Zoning), Section 20-42.130(E)(2)(c), (E)(4)(b), and (E)(10)(h), adopted by urgency Ordinance, March 3, 2020 (File REZ20-001)
c. No setback shall be required for an existing legally constructed living area, garage, or other accessory structure that is converted to an accessory dwelling unit with independent exterior access from an existing or proposed residence. A setback of five feet from the side and rear property lines is required for an accessory dwelling unit constructed above an existing legally constructed gara...
Tiny Homes
Santa Rosa allows one Tiny Home on Wheels per residential parcel as an accessory structure to an existing single-family home, capped at 400 square feet and 14 feet tall under City Code Section 20-42.220. A building permit and DMV registration are required, and the unit must meet 20-foot front, 5-foot side, and 5-foot rear setbacks.
Santa Rosa Tiny Home on Wheels Rules
Some RestrictionsSanta Rosa City Code § 20-42.220(D)(1)-(3)
1. Number allowed. No parcel may contain more than one Tiny Home on Wheels at any one time. 2. Dimensions. a. Maximum size. The maximum square footage for a Tiny Home on Wheels shall be 400 square feet, as measured from exterior wall to exterior wall. ... c. Height. No Tiny Home on Wheels shall exceed 14 feet in height, measured from bottom of wheels to top of roof. 3. Setbacks. Tiny Home on Wh...
Looking for Sonoma County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Santa Rosa city rules.
Accessory Structures in Sonoma County →