Residential Requirements for Hard-Wired Smoke Detectors in California

California Law

• California law requires the installation of smoke detectors in single, duplex and apartment homes. New homes built in California must have hard-wired, electrical smoke alarms with batteries to back them up; the California Electrical Code doesn’t directly mention smoke detectors but does specify the kinds of equipment and wiring to use when placing the warning systems into buildings. Older homes with no special wiring may use battery-only units.

Location Requirements

• The number of smoke detectors in a particular building depends on the structure’s size and floor levels. In a single home, alarms must be centrally located (in a hallway, for example) and placed outside of bedrooms and other sleeping areas. In other areas of a house, at least one smoke detector is required per floor. Apartment buildings must have an alarm in each stairwell. Hotels and other multi-resident buildings must place smoke detectors on the ceiling or wall of each bedroom.

Safety Rules

• Do not install smoke detectors near windows or vents where drafts can interfere with the units’ functions. They should not be installed directly inside kitchens, bathrooms and garages; instead, place them above an outside door. Replace batteries in smoke alarms once or twice a year, even if the detector is wired to the home’s electrical system. Test the system once a month; replace smoke detectors every ten years. Do not disconnect the batteries or borrow them for other purposes.

Home Sale Disclosure

• Houses and apartments are legally required to have operable smoke detectors; the California Association of Realtors says sellers must sign a document of assurance prior to the sale. Exemptions may be applicable -- for instance, if property is transferred between co-owners and family members or as the result of delinquent property taxes. Mobile homes must have at least one working smoke detector when the title of ownership is transferred.