Petaluma, CA Accessory Structures: Carport Rules (2026)

Permit Sonoma Policy 4-0-10 states that Permit Sonoma 'is the permit authority for any site-built additions, carports, garages, cabanas, ramadas, porches, decks and stairs.' Permit Sonoma instruction BPC-005 exempts only one-story detached tool or storage sheds of 120 square feet or less from building permits; carports and covered parking structures are not on the exemption list and require a permit. The BPC-002 Residential Plan Checklist sets construction standards: garage and carport floor surfaces must be of approved noncombustible material (asphalt is permitted at ground level in a carport per CRC R309.1 and R309.2), carports with no enclosed uses above do not require gypsum-board fire protection (CRC R302.6), and appliances in garages and carports must have burners at least 18 inches above the floor with bollard or impact protection (CMC 305.1). Exterior walls within 5 feet of a property line (3 feet with fire sprinklers) must be 1-hour fire-resistance rated. On the zoning side, district development criteria in Sonoma County Code Chapter 26 -- including Section 26-20-030 (R1), Section 26-18-030 (RR), Section 26-16-030 (AR), and Section 26-24-030 (R3) -- provide that no garage or carport opening facing the street may be located less than 20 feet from any exterior property line, with a reduction allowed where 25 percent or more of the lots on the block have already been improved with garages or carports.