Q. What are the requirements for smoke and carbon monoxide detectors when selling a house? 

A. State law requires that approved smoke and carbon monoxide detectors must be installed upon the sale or transfer of houses and that a Certificate of Compliance must be issued by your local fire department. As of 2010 a significant change became effective which requires a specific photoelectric smoke detector be installed within 20’ of kitchens and bathrooms (with a shower or bathtub). The risk of nuisance alarms from steam and cooking is lower with this type of detector. All smoke detectors installed outside of 20’ of kitchens and bathrooms must use a dual detector which has both ionization and photoelectric technology, or 2 separate detectors. This applies to all residences built before 1975, and is a recommended upgrade for house built after 1975.

Carbon monoxide alarms are required in all residences that have fossil fuel-burning equipment or an attached garage. Specific requirements for both smoke and carbon monoxide detectors vary depending on the year your house was built. 1 detector is always a must on each habitable level of living space, 1 for every 1200 sqft, 1 at the base of each stairway, 1 outside each sleeping area. Combination units are permitted. For specific requirements for your residence, contact your local fire department or Department of Fire Services at 978-567-3300 or www.mass.gov/dfs. 

Whether you own or rent, it is recommended that you test smoke and carbon monoxide detectors every month and replace the batteries twice a year. An easy reminder is to change the batteries when you change the clocks. Detectors that are over 10 years old should be replaced.