Petaluma, CA Fire Regulations: Smoke Detectors (2026)

085(X) of the Petaluma Municipal Code requires smoke alarms in all buildings, common areas, or portions used for human habitation, and sets out exactly where they must go: one on the ceiling or wall outside each separate sleeping area near the bedrooms, one inside each room used for sleeping, and one on every story of a dwelling unit, including basements and cellars, though not crawl spaces or uninhabitable attics. Split-level units without a door between adjacent levels can rely on a single upper-level alarm to cover the level below, but only if that lower level is less than a full story down.

Where construction is occurring, alarms must draw primary power from the building's wiring, carry a battery backup, and be permanently wired without a disconnect switch other than what overcurrent protection requires. The section allows battery-only alarms in narrower circumstances: buildings with no construction underway, buildings not served by commercial power, and existing areas undergoing alterations that do not expose the structure by removing interior wall or ceiling finishes, unless an attic, crawl space, or basement is available that would let wiring be run without removing those finishes. 085, so a missing or nonfunctional smoke alarm is treated the same as any other habitability defect for enforcement purposes.