Fire Department

Sale Of Property / Smoke Detector & Carbon Monoxide Alarm Permit Information


Inspections must be scheduled in person at Fire Headquarters, 491 Broadway. Payment must be made at this time. The permit counter is located on the second floor. (Handicap access obtained via the Emergency Communications Center) 

Permit Application Hours:  M-F   8:00am - 10:00am and 2:00pm - 3:00pm (except holidays).

The fees for Smoke / Carbon Monoxide Detector Inspections are as follows:
$50.00 for a single dwelling unit being sold
$100.00 for two dwelling units being sold
$150.00 for three to six dwelling units being sold
$500.00 for seven or more dwelling units
(Note: If you are selling 1 unit in a multi-apartment building, the single dwelling unit fee is applicable. The inspection fees cover both the smoke and carbon monoxide detector inspections)

Payment can be made by cash or check (make checks payable to the City of Cambridge). 

If paying by personal check, a form of identification (eg. drivers license) will be required. The City of Cambridge charges a $25 fee for returned checks. 

Please note: Certificate applications are available at the permit counter. The seller of the property must complete the application. Inspections are done by appointment only.  


Click here for the smoke detector / carbon monoxide permit: Residential Smoke/CO Detector Permit

Click here for more information about carbon monoxide detectors: Carbon Monoxide Information

Click here for more information about smoke and carbon monoxide detector requirements: Smoke/CO Detector Requirements

Click here for a smoke/carbon monoxide detector waiver: Smoke/CO Detector Waiver 

How To Obtain A Certificate For New Construction Or Renovated Buildings

If the building or unit has been newly constructed or renovated and is going to be sold, a Certificate of Occupancy issued by Inspectional Services will be required. A Smoke / Carbon Monoxide Inspection Certificate will be issued upon a satisfactory Certificate of Occupancy inspection. Please contact the Fire Prevention Office at (617) 349-4918. Both inspections will be done at the same time.

Effective April 5, 2010 - The Board of Fire Prevention Regulations has approved an emergency amendment to 527CMR 32 Approved Smoke Detectors. This regulation applies to units undergoing sale or transfer of buildings containing up to five residential units. The regulation, which was scheduled to go into effect January 1, 2010, has been moved to April 5, 2010. At that time, the regulation will still require photoelectric smoke detectors within 20 feet of a kitchen or bath containing a shower. Areas located beyond 20 feet will be required to contain dual detection (photoelectric and ionization) by either a single unit or two separate units. In addition to the date change, the regulation has been clarified to indicate it applies to residential units constructed prior to January, 1975 that have not undergone major alteration covered by the State Building Code. It also contains a provision for low voltage household warning systems that may have been installed in these homes.

Frequently Asked Questions:

Q: I live in a 3 unit building. Can I replace my common hallway smoke alarms with combination smoke/co alarms if they are located within 10 feet of the bedrooms.
A: No. Carbon Monoxide alarms are required within each dwelling unit.  

Q: Do I need a permit to install carbon monoxide alarms?
A: It depends. If you are installing a battery or plug-in type alarm, a permit will not be required. However, if you are installing carbon monoxide alarms as part of a fire alarm system, a fire alarm permit is required.

Q: I live in a building that does not have fossil-fueled burning equipment. I would like to have a carbon monoxide alarm installed. Is my landlord required to install the alarm?
A: No. The law applies to buildings that use fossil-fueled burning equipment only. 

Q: Does the law apply to business occupancies?
A: No. MGL148 26F 1/2 applies only to residential units. However, the Fire Department strongly recommends that carbon monoxide alarms be installed in businesses as well.

Q: Does the CO detector have to be located inside the bedroom?
A: The code does not prohibit a detector within the bedroom. This would normally apply to a 1-bedroom unit. If you have multiple bedrooms, code allows a detector to be placed in the immediate vicinity of the bedroom not to exceed 10 feet.

Q: I own a multiple apartment building. If I choose the alternative compliance option and install a monitored hard-wired detector in the boiler room and adjacent areas, am I still required to install detectors inside of each unit?
A: In addition to the hard-wired detector in the boiler room, code requires a detector be installed inside of each unit if the unit has a fossil fueled appliance. However, if the unit has no fossil fueled appliances, then a detector is not required.
Exception: In apartment buildings that have fossil fueled equipment in the basement or on the roof and there is no fossil fueled equipment in the apartments,  then a detector would be required in the apartments immediately above and/or below the rooms containing the  equipment.

Q: I would like to install hard-wire the detectors. Do they have to be installed by March 31, 2006?
A: No. The date for hard-wire installation has been extended to January 1, 2007 provided that written notification is made to the fire department no later than May 15, 2006.

Q: Will I be inspected by the fire department?
A: The fire department is required to inspect carbon monoxide installations only upon the sale of your unit or building. Please note, however, that if the fire department responds to your residence as a result of an emergency call or for any other reason, and it is observed that your residence does not have the required detection installed, a written violation may be served upon the owner of the residence. 

Q: Our property is a multiple condominium unit building and is eligible for the alternative compliance. Can the association choose to have the management company install the detectors?
A: The law states that the owners are responsible for the installation of the detectors. For condominium buildings, each owner will be responsible for the installation. If the property is eligible for the alternative compliance, the management company can perform the installation in accordance with the alternative compliance requirements, however, the management company will assume full responsibility for the entire building. Please contact your legal counsel for advice.

Visiting City Hall

Cambridge City Hall

795 Massachusetts Ave
Cambridge MA, 02139
Ph: 617-349-4000
TTY: 617-349-4242

Hours of Service

Monday: 8:30am-8pm
Tuesday-Thursday: 8:30am-5pm
Friday: 8:30am-12pm

Louis DePasquale
City Manager

Lisa C. Peterson
Deputy City Manager