Smoke & Carbon Monoxide Alarm Requirements

Information from the Massachusetts Division of Fire SafetyThere is hard evidence that properly installed smoke and carbon monoxide alarms save lives. Smoke and carbon monoxide detector inspections are required for consumer safety upon the sale or transfer of a property in Massachusetts. Requirements vary depending on the age and residential status of the property. The guidelines that follow are for informational purposes. NOTE: In Dec. 2016, requirements changed for homes built prior to 1975.

A complete guide on Massachusetts Smoke and Carbon Monoxide Requirements is available here.

Download a handy checklist for your Town of Dennis one or two family property:
(check with the local fire department for your town or village; regulations vary)

Built prior to 1975
Built 1975 to August 27, 1997
Built August 27, 1997 to January 1, 2008
Built after January 1, 2008

Note that all detectors should be installed following the manufacturer’s instructions.

Typical One- and Two-family Residences built before January 1, 1975

• Smoke detector requirements:
  One on every habitable level of the residence including the basement
  On the ceiling at the base of each stairway (but not in the stairwell itself)
  On the ceiling outside of each separate sleeping area
  Must be photoelectric; may be combo with ionization or with carbon monoxide alarm
  Must contain a “hush” feature to silence nuisance alarms
  May be battery powered, hardwired or a combination of both (applicable to the Town of Dennis; check with the fire department in other towns
  New battery-powered units must have a 10-yr, sealed, non-chargable, non-replaceable battery (Older units may be still be suitable if they are less than 10 years old; check specific regulations)
  Common areas within 2-family dwellings require alarms
• Carbon monoxide alarms are required as follows:
  On every level of the residence, including habitable portions of the attic and basement, and within 10 feet of each bedroom door
  Combination detectors (photoelectric smoke and carbon monoxide detector) may be used if within 20 feet of a kitchen or full bathroom
  Combination detectors (ionization smoke and carbon monoxide detector) may be used if outside of 20 feet of a kitchen or full bathroom
  May be either: battery powered, plug-in with battery backup, hardwired with battery backup, or system type

Typical One- and Two-family Residences permitted between 1975 and August 27, 1997

• Smoke Detectors required as follows:
  One on every habitable level of the residence
  On the ceiling at the base of each stairway
  On the ceiling outside of each separate sleeping area
  A minimum of one smoke detector must be installed for every 1200 square feet of living area per level
  Detectors must be hardwired interconnected
• Carbon monoxide alarms:
  On every level of the residence, including habitable portions of the attic and basement, and within 10 feet of each bedroom door
  Combination detectors (photoelectric smoke and carbon monoxide detector) may be used anywhere
  Combination detectors (ionization smoke and carbon monoxide detector) may be used if the detector is outside of 20 feet of a kitchen or full bathroom
  May be either: battery powered, plug-in with battery backup, hardwired with battery backup, or system type

Typical One- and Two-family Residences permitted after August 27, 1997

• Smoke detectors:
  One on every habitable level of the residence
  On at the base of each stairway
  On the ceiling outside of each separate sleeping area
  One smoke detector inside every bedroom
  A minimum of one smoke detector must be installed for every 1200 square feet of living area per level
  Must be hardwired and interconnected smoke detectors with battery backup
  If the smoke detector in within 20 feet of a kitchen or full bathroom, the smoke detector is required to be a photoelectric detector
• Carbon Monoxide alarms:
  On every level of the residence, including habitable portions of the attic and basement, and within 10 feet of each bedroom door
  Combination detectors (photoelectric smoke and carbon monoxide detector) may be used anywhere
  Combination detectors (ionization smoke and carbon monoxide detector) may be used if the detector is outside of 20 feet of a kitchen or full bathroom
  May be either: battery powered, plug-in with battery backup, hardwired with battery backup, or system type

Typical One- and Two-family Residences permitted on or after January 1, 2008:

• Smoke detectors required as follows:
  One on every habitable level of the residence
  On at the base of each stairway
  On the ceiling outside of each separate sleeping area
  One smoke detector inside every bedroom
  A minimum of one smoke detector must be installed for every 1200 square feet of living area per level
  Must be hardwired and interconnected smoke detectors with battery backup
  If the smoke detector in within 20 feet of a kitchen or full bathroom, the smoke detector is required to be a photoelectric detector
  If the smoke detector is outside of 20 feet of a kitchen or full bathroom, the detector is required to be either a photoelectric detector or a dual detector (containing both ionization and photoelectric technologies)
• Carbon Monoxide alarm requirements:
  On every level of the residence, including habitable portions of the attic and basement, and within 10 feet of each bedroom door
  Combination detectors (photoelectric smoke and carbon monoxide detector) may be used
  Must be hardwired and interconnected with battery backup (may be separate from existing smoke detection system)