Montgomery County Residential Smoke Alarm Requirements
The dates of Construction Permits dictate the type and location of smoke alarms. Smoke alarms powered by batteries alone are allowed if the home was built before building codes required hard-wired units. In Montgomery County, these are typically homes built prior to July, 1975. Effective January 1, 2018, all battery-only smoke alarms are required to be equipped with a 10-year, long-life nonremovable battery. For homes constructed after July 1, 1975 Code requires smoke alarms to be hard-wired directly into the home’s electrical system and have a battery back-up designed to keep the alarm functioning during a power outage. To know what type of smoke alarms you need, gather the answers to these questions:- What YEAR was the property built?
- Is the current smoke alarm system hard-wired with a battery back-up or battery-only?
- Where are the smoke alarms located?
| Installation Responsibility | Builder/Owner |
| Type of Alarm | Battery or Hardwired |
| Location | Outside each sleeping area Effective 1/1/2018: On every level |
| Installation Responsibility | Builder/Owner |
| Type of Alarm | Hardwired |
| Location | Outside each sleeping area Effective 1/1/2018: On every level |
| Installation Responsibility | Builder/Owner |
| Type of Alarm | Hardwired and interconnected |
| Location | Outside each sleeping area and on every level |
| Installation Responsibility | Builder/Owner |
| Type of Alarm | Hardwired, interconnected with battery back-up |
| Location | Outside each sleeping area and on every level |
| Installation Responsibility | Builder/Owner |
| Type of Alarm | Hardwired, interconnected with battery back-up |
| Location | For all new residential units constructed after 7/1/1997, at least one smoke alarm must be installed in each sleeping room in the hallway or common area outside of sleeping rooms and in the hallway or common area on each level of a residential unit, including basements and excluding unoccupied spaces such as attics. |
Effective: January 1, 2018 UPDATE to Maryland's Smoke Alarm Law applicable to battery-only smoke alarms and their locations.
| Installation Responsibility | Owner |
| Type of Alarm | Battery-only powered smoke alarms must be sealed, tamper resistant units with a silence/hush button and a nonremoveable 10-year long-life battery. Hard-wired (AC Powered) smoke alarms must ONLY be replaced with hard-wired smoke alarms with a battery back-up. The back-up battery is not required to be sealed-in or a specific battery type however 10-year long life batteries are always recommended. At NO time is an existing hard-wired smoke alarm permitted to be replaced with any type of battery-only smoke alarm. |
| Location | Minimum locations: one on every level, including the basement & one outside each sleeping area. |
- Monthly – using the test button, check smoke alarms to ensure they are working.
- Smoke alarms expire. The life expectancy of smoke alarms is 10 years, after which point the alarm’s sensors lose sensitivity and become unreliable. The test button only confirms that the battery, electronics and alert system are working, it does not mean that the smoke sensor is working. To find out how old your smoke alarm is and its expiration date, look on the back of the alarm where the date of manufacture is marked. Smoke alarms should be replaced 10 years from that date (not the date of purchase).
Nothing in the new law is intended to imply that smoke alarms are an adequate substitute for residential sprinkler protection. The combination of properly located and functioning smoke alarms along with a properly designed residential sprinkler protection system provides the greatest potential for surviving a fire in your home.
Additional Information:
- Smoke and Carbon Monoxide Alarms that are tied to an approved fire alarm control panel or household fire alarm system monitored 24/7 and installed in the specified locations are not affected by this law. These systems must have a functioning battery back-up.
- There are manufacturers offering battery-only smoke alarms with “long life” replaceable lithium batteries. These DO NOT meet the requirements of the law because the batteries are not sealed in.
- Whether purchasing new alarms or researching your current alarms, check the Consumer Product Safety Commission (CPSC) Recall List to make sure the alarms you have or may be considering are not on their recall list. Visit www.cpsc.gov/Recalls and type “Smoke Alarms” in the search window and scroll through the list of recalled alarms.
Three things you need to know:
- Maryland’s Smoke Alarm Law requires the replacement of all smoke alarms (hard-wired and battery-only) when the alarm exceeds 10 years from the date of manufacture (printed on the moke alarm) or sooner if the smoke alarm fails to operate.
- The law requires the replacement of all battery-only powered smoke alarms, typically pre-1975 construction, with 10-year, long-life, sealed battery smoke alarms with a “silence” or “hush button” feature.
- Smoke alarms are required on every level of the home.
Home Renovations:
Under certain circumstances, the owners of homes built before the hard-wiring requirements were enacted must install updated smoke alarm systems if they undertake a home renovation project. Contact the Office of Code Compliance, Permitting Services, at 240-777-0311 for information.
Montgomery County Residential Smoke Alarm Requirements available in PDF.