Massachusetts Real Estate


Massachusetts Smoke Detector Laws Changing as of January 2010

** Correction the Massachusetts smoke detector compliance has been extended from Jan 1st until April 5th 2010.

Whenever a home is sold in Massachusetts it is required that the home is inspected by the local fire department for properly working smoke detectors. This law has been in place for decades and is designed to save lives. A property can not change hands without a certificate issued by the fire department.

Effective April 5, 2010, a new regulation relating to the installation and maintenance of certain smoke detectors will be put in place. Staying up to speed on a change in the law like this is critical for landlords, home owners and Realtors alike.                                                                                                       

It goes without saying that it is imperative that home owners ensure that their properties comply with these laws, both from a public safety and liability stand point.  In order to know exactly how your property could be impacted it would be prudent to speak with the local fire Marshall or a lawyer that is well versed in this new amendment.                                                                             


There are two primary detection methods used in todays smoke detectors. They can be either ionization or photoelectric.

Ionization detectors typically have a constant current running between two electrodes. When smoke hits the device, it blocks the current which causes the alarm to trip.

Ionization detectors are usually faster to go off than photoelectric detectors.  The problem with ionization detectors though is that they are unable to differentiate between smoke and steam.

This makes them prone to false alarms when steam from a shower or other source interrupts the current. This is especially true when the ionization detector is placed near a kitchen or bathroom. 

Photoelectric detectors send a beam of light. This beam passes in front of the detector in a straight line. When smoke crosses the path of the light beam, some light is scattered by the smoke particles causing it to trigger the alarm.  Photoelectric detectors are less sensitive to false alarms from steam or cooking fumes but can take longer than ionization detectors to work.

Another major concern was that ionization detectors do not offer the best protection in smoldering fires which are some of the deadliest blazes across the country. Photoelectric smoke alarms are more sensitive to smoldering smokey fires. Most of the homes across the country have ionization detectors which are more sensitive to flames.

In 2007, WBZ News in Boston tested both types of smoke alarms. In a smoky fire the photoelectric detector sounded the warning first. While took almost 17 minutes into the fire before the ionization alarm finally went off!

The debate in Massachusetts has been whether to require property owners to replace their ionization detectors with photoelectric detectors.

Home owners have raised concerns about the cost of replacing smoke detectors that still function properly. Fire departments have suggested that the elimination of false alarms outweighs the additional expense that home owners will need to deal with.



Since there are strengths and weaknesses of photoelectric versus ionization smoke detectors, the Board of Fire Prevention Regulation has passed a new regulation (527 CMR 32.00 et seq).

According to the new regulation, owners of certain residential buildings will be required to install and maintain both the ionization and photoelectric smoke detectors.

  While the new regulation does not change the locations where smoke detectors are required, it does allow the installation of both technologies in certain locations. 

Under the new regulation, an ionization dectector can not be placed within 20 feet of a kitchen or a bathroom containing a shower or a tub. In these locations only a photoelectronic detector is allowed. 

All property owners should determine what type of smoke detectors they are currently have installed. In order to comply with the law you can either install two separate detectors that have both technologies or by installing one that utilizes both.





In order to determine if your property is affected by this change in the law it would be prudent to check with your local fire department or a local Real Estate attorney who up to speed on the changes in the law. According to to the new amendment the following types of properties are impacted by the new regulation:

  • Residential buildings under 70 feet tall and containing less than six dwelling units.

  • Residential buildings not substantially altered since January 1, 1975, and containing less than 6 residential units.

  • All residential buildings sold or transferred after April 5, 2010, which are less then 70 feet tall, have less than six units, or have not been substantially altered since January 1, 1975.

For all properties in these categories, compliance is mandated by April 5, 2010.  It should be noted that the law does not apply to these larger buildings or those which were substantially altered since January, 1975, as these properties already were required to upgrade their fire safety systems under other existing laws.

If you are selling your home in Massachusetts one other law that you need to be aware of is what is known as Nicole's Law. As of March 2006 when a home is transferred you need to have working carbon monoxide detectors.

Carbon Monoxide detectors are required in any residence that has fossil-fuel burning equipment including, but not limited to, a furnace, boiler, water heater, fireplace or any other apparatus, appliance or device; or has enclosed parking within its structure.

Unfortunately, the law is named for 7-year-old Nicole Garofalo who died in January 2005 when a heating vent in her house was blocked by snow drifts, allowing carbon monoxide to accumulate in the home.

According to the carbon monoxide regulations, you need to have a detector on each finished level of the home. Further there must be a detector placed within ten feet of all the bedroom doors. The detectors do not need to be hard wired. A plug-in or battery operated detector meets the requirements.

The inspection for both the smoke and carbon detectors are done by the local fire department prior to closing.


About the Author: The above Real Estate information on Massachusetts smoke detector laws was providedRE/MAX Executive Realty Hopkinton MA by Bill Gassett, a Nationally recognized leader in his field. Bill can be reached via email at or by phone at 508-435-5356. 

Have a home to sell in Metrowest Mass? I have a passion for Real Estate and love to share my marketing expertise! 

For Metrowest Massachusetts Real Estate and homes see Metrowest Mass Real Estate. Want to have MLS access to beat other buyers to your dream home? Sign up with no obligation at my MLS Property Finder Site.

I service the following towns in Metrowest Massachusetts: Hopkinton, Milford, Upton, Southboro, Westboro, Ashland, Holliston, Mendon, Hopedale, Medway, Grafton, Northbridge, Uxbridge, Franklin, Douglas, and Framingham MA.

Click here to view Bill Gassett's Real Estate profile.




Subscribe in a reader



Building lasting relationships by helping people move in and out of Metrowest Massachusetts for the last 24 years.

Connect with me on

Comment balloon 54 commentsBill Gassett • February 09 2009 02:08PM
Massachusetts Smoke Detector Laws Changing as of January 2010
** Correction the Massachusetts smoke detector compliance has been extended from Jan 1st until April 5th 2010. Whenever a home is sold in Massachusetts it is required that the home is inspected by the local fire department for properly working… more