Maryland Smoke Detector Law (2023)

Maryland’s new smoke detector law that became effective in 2018 is codified in Md. Public Safety § 9-104.  The law is unchanged in 2023.

This law requires that every sleeping area in a residential dwelling, including one and two-family homes, apartment buildings, dormitories, and hotels, must have an automatic smoke alarm. To comply with the law, a smoke alarm must meet the following four conditions:

  1. it must be installed in accordance with the National Fire Alarm Code,
  2. listed and labeled by a nationally recognized testing laboratory,
  3. capable of sensing visible or invisible particles of combustion, and
  4. capable of sounding an alarm to alert people in the sleeping area.

The statute reads as follows:

§ 9-104. Automatic smoke alarms required in residential sleeping areas

maryland smoke detector lawIn general

(a)(1) At least one smoke alarm shall be provided in each residential sleeping area.
(2) Smoke alarms required in one- and two-family dwellings constructed before July 1, 1975, shall be battery powered or alternating current (AC) primary electric powered units.
(3) Smoke alarms required in one- and two-family dwellings constructed between July 1, 1975, and June 30, 1990, shall be alternating current (AC) primary electric powered units.
(4) Smoke alarms required in multifamily residential occupancies including apartments, lodging or rooming houses, dormitories, and hotels shall be alternating current (AC) primary electric powered units.
(5) Smoke alarms required in a residential occupancy constructed on or after July 1, 1990, shall be alternating current (AC) primary electric powered units with battery backup or an approved alternate secondary power source.

Smoke alarms installed in each level of residential occupancy

(b) At least one smoke alarm shall be installed in each level of a residential occupancy constructed on or after January 1, 1989, including basements and excluding unoccupied attics, garages, and crawl spaces.
Arrangement of two or more smoke alarms within residential unit
(c) If two or more smoke alarms are required within a residential unit constructed on or after January 1, 1989, the smoke alarms shall be arranged so that activation of any one smoke alarm causes alarm activation of all other required smoke alarms within the residential unit.
Smoke alarm placement upgrades
(d)(1) Subject to paragraph (2) of this subsection, smoke alarm placement in a one- or two-family dwelling shall be upgraded to comply with paragraph (3) of this subsection in existing residential occupancies when any one of the following occurs:

(i) the existing smoke alarms exceed 10 years from the date of manufacture;
(ii) the existing smoke alarms fail to respond to operability tests or otherwise malfunction;
(iii) there is a change of tenant in a residential unit and the residential unit has not previously been equipped in accordance with this subtitle with sealed long-life battery smoke alarms with silence/hush button features within the 10 years preceding the change of tenant; or
(iv) a building permit is issued for an additional residential unit or alteration to a residential unit.

(2) Smoke alarm placement shall be upgraded to comply with paragraph (3) of this subsection in all existing residential occupancies on or before January 1, 2018.
(3) Upgraded smoke alarm placement shall include the following:

(i) a minimum of one smoke alarm on each level of the residential unit, including basements and excluding unoccupied attics, garages, and crawl spaces;
(ii) smoke alarms shall be alternating current (AC) primary powered units with battery backup, except as follows:

1. smoke alarms in one- and two-family dwellings constructed before July 1, 1975, may be battery operated; and
2. smoke alarms required in new locations by this section, if smoke alarms did not previously exist, may be battery operated; and

iii) if battery operated smoke alarms are permitted, only sealed, tamper resistant units incorporating a silence/hush button and using long-life batteries may be used.

Smoke detectors installed as approved household fire alarm systems

(e) In one- and two-family dwellings, a smoke detector installed as a part of an approved household fire alarm system is an acceptable alternative to the AC powered-battery backup smoke alarms required by this section, if the smoke detectors are installed and located as specified in subsection (a) of this section.

Smoke detectors installed as part of approved fire alarm system

(f) A smoke detector installed as a part of an approved fire alarm system is an acceptable alternative to the AC powered-battery backup smoke alarms required by this section, if the smoke detectors are installed and located as specified in subsection (a) of this section.

What the Maryland Smoke Detector Law Requires

Here is a summary of the key requirements of the law:

  1. Smoke detectors must be installed on every level of a home, including basements and habitable attics.
  2. Smoke detectors must be placed outside of sleeping areas, within close proximity to bedrooms.
  3. It’s recommended that smoke detectors also be installed inside bedrooms.
  4. For new construction or homes undergoing major renovations, hardwired interconnected smoke detectors with battery backup are required.
  5. Again, Maryland law how requires that when replacing a battery-only operated smoke alarm that is more than 10 years old, the new alarm must be powered by a 10-year, sealed-in battery with a “hush” feature that temporarily silences the alarm.
  6. The law also requires homeowners to ensure that their smoke alarms are less than 10 years old, based on the manufacture date.

Definitions (MD Code, Public Safety, § 9-101)

Another Maryland statute, MD Code, Public Safety, § 9-101, defines what some terms in the smoking detector law mean:

(a) In this subtitle the following words have the meanings indicated.
Long-life battery
(b) “Long-life battery” means a nonrechargeable, nonreplaceable primary battery that is capable of operating a smoke alarm for at least 10 years in the normal condition.
Sleeping area
(c) “Sleeping area” means a space that includes one or more sleeping rooms and a hall or common area immediately adjacent to any sleeping room.
Sleeping room
(d) “Sleeping room” means an enclosed room with a bed arranged to be used as a bedroom.
Smoke alarm
(e) “Smoke alarm” means a single or multiple station device that detects visible or invisible products of combustion and includes a built-in internal alarm signal.
Smoke detector
(f) “Smoke detector” means a system-connected smoke sensing device tied to a fire alarm control panel or a household fire warning panel.

What Was the Biggest Change in 2018 in the Maryland Smoke Detector Law?

Maryland law now requires all Maryland residents to have 10-year lithium batteries on their smoke detectors that are tamper-resistant with the silence/hush feature. There must be one on every level of a home.

Are Carbon Monoxide Detectors Mandated in Maryland?

Maryland law now requires carbon monoxide detectors. But the requirement only extends to Maryland homes built after 2007. But forget the law. Be smart. Everyone house should have a CO2 detector.

  • Let’s let the Maryland fire marshall explain the law
  • For a fire alarm to be effective, it has to actually work.  These are the top causes of fire alarm failure.