Single family and two-family homes sold in MA must be inspected by the local fire department to confirm the operation of smoke detectors and carbon monoxide detectors. A smoke certificate is issued for the closing. It is important for property owners to know the MA smoke detector requirements and smoke detector technologies in order to be in compliance (even if they are not planning to sell their home).

Smoke Detector Technologies

There are two primary types of smoke detectors, ionization and photoelectric. Each has different pros and cons relating to recognizing smoke versus flames.

Ionization Technology

Ionization detectors contain two electrodes and current that runs between them. Smoke interferes with this current and causes the alarm to sound. This technology is good at detecting flaming fires but cannot differentiate between smoke and steam. Thus, they are prone to false alarms when placed near kitchens and baths.

Photoelectric Technology

Photoelectric smoke detectors have a beam of light. Smoke or fire can interrupt the beam and activate the alarm. It is very accurate at recognizing smoldering fire and is not as sensitive to false alarms from kitchen smoke or shower steam.

MA Smoke Detector Requirements

MA rules mandate the kinds and installation of smoke detectors in residential buildings. The details differ depending on when a property was built or renovated. The following is an overview of the installation of smoke detectors inside a home.

Location before 1975 1975 to Aug. 27, 1997 after Aug. 27, 1997 on or after Jan. 1, 2008 on or after Feb. 4, 2011
Power Supply Hardwired
or
Battery		 Hardwired
Interconnected		 Hardwired
Interconnected
Battery Backup		 Hardwired
Interconnected
Battery Backup		 Hardwired
Interconnected
Battery Backup
Every Level of Living Yes Yes Yes Yes Yes
Base of Each Stairwell Yes Yes Yes Yes
Outside Each Sleeping Space Yes Yes Yes Yes Yes
Minimum 1 for Every 1,200 sf Finished Space per Floor Yes Yes Yes Yes
Inside Every Bedroom Yes Yes Yes
In Basement Yes
Bottom of Every Stairway to a finished level Yes
Within 20ft. of Kitchens/Baths Photoelectric Photoelectric Photoelectric Photoelectric
Outside of 20ft. of Kitchens/Baths Both Ionization & Photoelectric Photoelectric OR Dual Photoelectric

Additional Information

Additional information on MA smoke detector requirements can be viewed at http://www.mass.gov/eopss/agencies/dfs/dfs2/osfm/fire-prev/smoke-alarm-regulations.html. Note that the above information is merely an overview, should not be interpreted as legal advice and is subject to change without notice. Additionally, cities and towns may impose additional laws beyond state mandated ones. Contact your local fire department to obtain comprehensive and current information for your property.