Requirements for Residential Smoke & Carbon Monoxide Detectors

A few years ago, we published a blog about the established California smoke and carbon monoxide (CO) detector requirementsEnsuring your home is properly outfitted with these lifesaving devices is vital and we wanted to take the time to revisit and reinforce the importance of bringing your Silicon Valley or Santa Cruz County home up to code.


According to Cal Fire, two thirds of home fire fatalities occur in residences without operable smoke detectors. This means, the detectors have been disconnected or the batteries are dead. Most fire-related fatalities occur while families are sleeping, so it is even more critical that the detectors warn residents early on. Functional smoke detectors increase the chances of surviving a home fire by 50%.

Homes that are constructed after 1992 are required by California law to have hardwired smoke detectors while those built prior to 1992 can have battery-operated units. In July 2014, California law SB 745 made it mandatory that all battery operated smoke detectors must include a non-removable battery rated to last 10 years.

There may be additional smoke detector requirements depending upon where you live. For the specific guidelines in your city, check with the local building and safety department.


Smoke detectors should be placed in every bedroom, in all hallways leading to bedrooms as well as on each level of your house including basements. Smoke alarms should be mounted on the ceiling four inches away from walls. Wall mounted units should be placed four to twelve inches from the ceiling and all units should be placed away from windows or heating/air conditioning vents.


Cal Fire suggests testing all smoke detectors monthly by holding down the test button although others suggest testing twice a year during the time change (approximately March and November). If the alarm sounds, the battery is functional. Keep all units free of dust and cobwebs, which can impair the unit’s ability to sense smoke. Vacuum all units annually and replace batteries in hardwired units at least once a year. If the alarm chirps, (something we’ve all experienced most likely in the middle of the night!) this indicates the battery is running low. If it is a battery-only detector, remove and replace the entire unit as soon as possible. If it is a hardwired/battery backup detector, immediately replace the battery.


If your smoke detector sounds, especially at night, drop to the ground to get below the smoke and crawl to the nearest exit. Do NOT try to take any belongings with you-the most important thing is your safety and that of your family members. Once you are outside, do not try to reenter your home. Call 9-1-1. Be sure to have a predetermined family escape plan and a designated meeting point. Review this plan and practice with your family and children multiple times a year.


The Carbon Monoxide Poisoning Prevention Act of 2010 makes it a requirement for single-family homes with an attached garage or a fossil fuel source (gas burning appliances, furnace, HVAC unit, fireplace, etc.) to install carbon monoxide detectors within the home. Owners of multi-family leased or rental dwellings, such as apartment buildings, rented single family homes and duplexes are also obligated to install CO detectors.


An invisible and odorless gas, carbon monoxide can have deadly effects within minutes. CO results from the burning of fuels including gas or propane, oil, kerosene, wood, or charcoal. If appliances that use these fuel sources are properly used and maintained, the amount of CO generated is minimal. But, when an appliance isn’t operating correctly or they are used improperly, dangerous and deadly levels of CO can result.


Symptoms of CO poisoning are similar to those of the flu, food poisoning and other sicknesses, many people don’t consider carbon monoxide as a possibility, which is what makes these detectors so important in homes. Symptoms include:

  • Headaches
  • Dizziness
  • Nausea
  • Shortness of breath
  • Mental confusion
  • Tightness of the chest
  • Lethargy

If your family members are experiencing the above symptoms, especially if they appear somewhat suddenly, turn off any operating fuel sources, open windows and doors, and get outside right away, even if you have detectors that do not sound. Do NOT reenter your home. Call 9-1-1 and let them know you suspect a CO leak.


CO alarms should be installed outside of each sleeping area as well as one unit on every level of your house, again including basements. These inexpensive detectors can be purchased at any home improvement store and can be hardwired, plugged into an electrical outlet, or battery-operated. CO detectors should be placed on the wall or ceiling as noted by each manufacturer. Units that need plugged into an electrical outlet will obviously be lower to the ground but in general, they should be at or near the same level as smoke detectors. Be sure to keep detectors at least 15 feet from any fuel-burning appliance. Additional information on carbon monoxide and CO alarms is available on the Cal Fire website.


Upkeep of carbon monoxide units should follow the same protocol as smoke detectors. Check monthly, replacing the entire unit or battery as warranted. Keep free of dust and debris.


If your carbon monoxide detector sounds, exit your home immediately. Call 9-1-1, do not reenter your home until emergency personnel have inspected your property and informed you it is safe to go back inside.


If you sell your home, it must meet the mandatory state requirements for both smoke and CO detectors. You will need to provide documentation to the buyer proving compliance with California’s smoke and carbon monoxide detector laws and regulations. Your REALTOR® can assist you in assessing whether your home conforms to the regulations and bringing it into compliance if it falls short.

The Dawn Thomas Team artfully unites special homes with extraordinary lives in Silicon Valley and Santa Cruz County. Contact us today and we can assist you in selling or buying your home.