NYC natural gas detector law: what owners and tenants need before January 1, 2027
New York City already requires smoke and carbon monoxide (CO) detectors in most homes. Starting January 1, 2027, buildings with gas piping also need natural gas detectors (alarms) under Local Law 157 of 2016, as updated by Local Law 102 of 2025. If you own a rental building, or a one- or two-family house you don't live in, the deadline is about ten weeks away. Here's who has to comply, where the alarm goes, who can install it, and what tenants pay and do.
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Emergency? Gas smell, CO alarm, fire, sparking or flooding: get to safety and call 911 first.
Who has to install gas detectors
According to HPD and NYC311, owners must provide and install at least one approved, working natural gas detector in each unit of:
- Apartment buildings (Class A multiple dwellings)
- Hotels, rooming houses and other Class B multiple dwellings (these can use a centrally monitored zoned system in public corridors and spaces instead)
- One- and two-family homes that are not owner-occupied
The rule applies when the building has gas piping. A building with no gas piping can be exempt, and HPD says it will publish an exemption filing process. DOB also says a unit with no gas appliance of its own still needs an alarm if it sits directly above a space with a gas appliance or gas piping.
The three detectors, side by side
- Smoke detector: required in every unit of a multiple dwelling, within 15 feet of the primary entrance to each sleeping room.
- Carbon monoxide detector: required in every unit of a multiple dwelling, and in non-owner-occupied one- and two-family homes, when the building has a fossil fuel burning device (a gas or oil boiler, furnace, water heater or stove). Also within 15 feet of each sleeping room's entrance.
- Natural gas detector: required where there's gas piping, starting January 1, 2027.
All of them must have an end-of-life alarm, and none may be painted over. Owners can use a combination device instead of separate units, as long as the placement meets each requirement.
Where the gas alarm goes
DOB's installation rule (1 RCNY §908-02) says that when a gas-burning appliance is in the apartment, usually the stove or a gas water heater, the natural gas alarm goes in the same room as the appliance, at least 3 feet and no more than 10 feet away from it, measured horizontally. For a unit above a gas appliance or gas piping, DOB says the alarm goes on the ceiling, or within 12 inches of the ceiling, in the room directly above. Alarms must be listed and labeled to UL 1484. Follow the manufacturer's mounting instructions too.
Who can install it
- Battery or plug-in alarms: anyone can install them, including the owner, building staff or the tenant, according to DOB and NYC311.
- Hard-wired alarms and central systems: must be installed by an NYC licensed electrical contractor who pulls the required DOB permits. Line-operated zoned detection systems in Class B buildings also need FDNY plan review.
DOB says existing buildings (those with a certificate of occupancy before January 1, 2027) may use battery-powered alarms. Buildings completed after that date need AC primary power plus a backup source.
What owners must do besides installing
- Give notice. When you install, give at least one adult in each unit written information on testing and maintenance, what to do if an alarm sounds, and the device's useful life.
- Post the notice. Multiple dwellings post a notice at the building entrance. HPD has sample notices, including a combined smoke, CO and gas version.
- Keep records of when notices were posted, when each device was installed, and each device's expiration date.
- Replace on time. Replace devices when they reach the end of their useful life, before a new tenant moves in if one is missing or broken, and within 30 days if one fails within a year because of a defect.
What tenants pay and do
HPD says tenants in Class A buildings and in rented one- and two-family homes reimburse the owner $25 for each newly installed smoke, CO or natural gas detector, $50 for a two-in-one device, or $75 for a three-in-one. You have one year from installation to pay. Tenants in Class B buildings (hotels, rooming houses) don't pay.
Tenants have to test every detector at least once a month, change batteries at least twice a year (Daylight Saving Time ends Sunday, November 1, 2026, a good reminder), replace a low battery right away when it chirps, and never paint over a detector.
If a gas or CO alarm goes off
Don't hunt for the source and don't flip switches. Get everyone out, then call 911 from outside. For a gas smell you can also call your utility from outside: Con Edison 1-800-752-6633 or National Grid (Brooklyn, Queens, Staten Island) 718-643-4050. If the gas gets shut off, see our gas shutoff guide for how service gets restored. For CO, NYC Health lists boilers, furnaces, water heaters and using a gas stove for heat among the common sources. If your boiler won't restart afterward, see boiler won't turn on.
Getting help before the deadline
Most owners of small buildings can install battery or plug-in alarms themselves. If you want hard-wired or interconnected alarms, you need an NYC licensed electrical contractor with a permit. Ask for the license number and a written quote, and check it with our contractor license guide. If you own the building, you can ask us to match you with a local licensed electrician.
Questions
When do NYC buildings need natural gas detectors?
By January 1, 2027, for covered residential buildings with gas piping, under Local Law 157 of 2016 as updated by Local Law 102 of 2025.
Do one- and two-family homes need gas detectors?
Yes, if the home isn't owner-occupied (it's rented out) and it has gas piping. HPD and NYC311 list one- and two-family homes among the covered buildings.
Where should a natural gas alarm be installed?
Per DOB, in the same room as the gas appliance, 3 to 10 feet away horizontally. In a unit directly above gas piping or an appliance, it goes on or within 12 inches of the ceiling of the room above.
Do I need an electrician to install a gas detector?
Not for battery or plug-in alarms; owners, building staff or tenants can install them. Hard-wired alarms must be installed by an NYC licensed electrical contractor with DOB permits.
How much does a tenant pay for a new gas detector?
HPD says $25 for each smoke, CO or natural gas detector, $50 for a two-in-one, or $75 for a three-in-one device, payable within one year. Class B tenants don't pay.
Sources
Rules and phone numbers can change. Check the official source before relying on them.
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Published 2026-10-23 · Updated 2026-10-23
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