Accessory Structures in Petaluma, CA (2026)
7 verified accessory structures rules for Petaluma, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Petaluma allows one detached accessory dwelling unit on any single-family lot, plus a junior ADU inside the home under Section 7.035, subject to size, setback, and parking rules in IZO Section 7.030. State ADU law overrides any local requirement in this section that conflicts with Government Code Sections 66310 through 66342.
Petaluma Accessory Dwelling Unit Zoning Standards
Some RestrictionsPetaluma Implementing Zoning Ordinance § 7.030(A), (C)(1), (D), (G), (P)
A. Zoning. An accessory dwelling unit may be created within a residential or mixed-use zone, including planned unit developments. ... ... 1. Single-Family Lots. One detached accessory dwelling unit is permitted on a lot with a proposed or existing single-family dwelling. ... ... D. Size of Unit. The maximum allowable living area of an accessory dwelling unit is 1,000 square feet; provided, howe...
ADU Impact Fees
Petaluma exempts junior accessory dwelling units from local utility connection fees. IZO Section 7.035(L) and (M) waive both the water connection fee and the sewer connection fee that would otherwise apply when a homeowner builds a JADU inside an existing single-family home, cutting one of the largest out-of-pocket costs for adding a small second unit.
Petaluma Junior ADU Water and Sewer Fee Waiver
Few RestrictionsPetaluma Implementing Zoning Ordinance § 7.035(L), (M)
L. No Water Connection Fees. No water connection fee is required for the development of a junior accessory dwelling unit. M. No Sewer Connection Fee. No sewer connection fee is required for the development of a junior accessory dwelling unit.
ADU Owner Occupancy
Petaluma requires the owner of a parcel with a junior accessory dwelling unit (JADU) to live in either the primary house or the JADU as a principal residence under IZO §7.035(C), unless the property belongs to a government agency, land trust, or nonprofit housing operator building affordable units. Standalone accessory dwelling units carry no such state-preempted owner-occupancy mandate.
Petaluma Junior ADU Owner-Occupancy Rule
Some RestrictionsPetaluma Implementing Zoning Ordinance § 7.035(C)
C. Owner Occupancy. The owner of a parcel with a single-family dwelling and a proposed junior accessory dwelling unit shall occupy as a principal residence either the primary dwelling or the accessory dwelling, except when the home is owned or operated by a government agency, land trust, or nonprofit housing organization for use as affordable housing.
ADU Rental Restrictions
Petaluma bars short-term rentals of accessory dwelling units permitted after September 7, 2017, requiring every rental term to run more than 30 days under IZO §7.030(P). The same subsection expressly forbids licensing any such ADU as a short-term vacation rental under §7.110.
Petaluma ADU 30-Day Minimum Rental Rule
Significant RestrictionsPetaluma Implementing Zoning Ordinance § 7.030(P)
P. Rentals. All accessory dwelling units permitted after September 7, 2017, shall only be rented for a term of more than 30 days. No accessory dwelling units permitted after September 7, 2017, shall be permitted as a short term vacation rental under Section 7.110.
Shed & Carport Rules
A detached shed or other accessory structure in Petaluma's RR and R1 zones cannot sit in the required front setback at all, needs only a 4-foot interior side setback and 5-foot rear setback, but must keep a 40-foot (RR) or 30-foot (R1) street-side setback, and its footprint is capped at 10% of the required setback area or 500 square feet, whichever is greater.
Petaluma Shed and Accessory Structure Setbacks
Some RestrictionsPetaluma Implementing Zoning Ordinance § 4.040, Table 4.6, Detached Accessory Structure rows
| " | RR | R1 | | Detached accessory structure | | | Front | Not Permitted | Not Permitted | | Side – Interior (each) | 4 ft | 4 ft | | ...
Garage Conversions
Converting a garage into living space anywhere in Petaluma requires a building permit and continued compliance with the zoning ordinance's off-street parking requirements under IZO §7.060(J), so a homeowner must show any required parking lost in the conversion is still satisfied before the project is approved.
Petaluma Garage Conversion Permit Rule
Some RestrictionsPetaluma Implementing Zoning Ordinance § 7.060(J)
J. Garage Conversions. Conversion of a garage to living space requires a building permit and compliance with the parking requirements of this ordinance.
Tiny Homes
Petaluma regulates tiny houses through the state building code it adopts by reference rather than a standalone city ordinance. Municipal Code § 17.04.010(C) adopts the California Residential Code's Appendix BB, Tiny Houses, in its entirety, so a tiny house built on a foundation in Petaluma must meet those state standards and go through the city's normal building-permit process.
Petaluma Tiny House Building Rules
Some RestrictionsPetaluma Municipal Code § 17.04.010(C)
Pursuant to Section 50022.2 of the California Government Code, the following codes are adopted by reference, including the amendments listed in this chapter which are made pursuant to the findings of fact set forth in the ordinance codified in this section: ... Part 2.5—2025 California Residential Code based on the 2024 International Residential Code including Appendix BG (Sound Transmission), ...
Looking for Sonoma County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Petaluma city rules.
Accessory Structures in Sonoma County →