Smoke and carbon monoxide alarms in Michigan: what the law says and what the state advises

What the carbon monoxide statute covers

MCL 125.1504f is Michigan’s statute on carbon monoxide devices in homes, and its reach is narrower than many pages say. It calls for at least one operational approved CO device in three situations: initial construction of a single- or multifamily dwelling, renovation of an existing single-family dwelling where a permit is required, and the addition or creation of a bedroom. “Approved” means listed to ANSI/UL 2034 or 2075.

The statute also says where the device goes: in the vicinity of bedrooms, in areas adjacent to an attached garage, and adjacent to fuel-burning appliances. The statute reads as allowing battery, plug-in, or hardwired devices with battery backup. An older house that has had no permitted work is not caught by that wording, so whether you must add one depends on what you are doing to the house.

Placement advice from LARA

LARA published an advisory on the 2015 Michigan Residential Code because that code gives no CO detector locations, and the advisory points back to the statute. It adds that installation follows the manufacturer’s instructions and that a detector should stay out of very humid areas and not sit within 15 feet of fuel-burning heating or cooking appliances.

What the state advises for smoke alarms

On smoke alarms, the one gap is rule text: nothing we read settles hardwired versus battery units, for new or existing homes. The state does offer guidance. In a news release dated Oct 31, 2025, LARA and the Bureau of Fire Services recommended hardwired alarms or alarms with 10-year lithium batteries and monthly testing. It advised smoke alarms on every level, inside every bedroom and outside sleeping areas, and CO alarms on each level. It said to replace smoke alarms every 10 years and CO alarms every 5 to 7 years, or as the manufacturer directs.

That is guidance, not law, though it is the most specific Michigan statement on the subject. When you buy alarms, the 10-year date on the back of the unit tells you when yours is due.

When it counts as electrical work

A battery alarm screwed to a ceiling is not wiring. A hardwired or interconnected alarm is: Michigan defines electrical wiring as including devices for the distribution and use of electrical energy in or on a building, and only an individual licensed under Article 7 installs it, unless the homeowner exemption applies. That exemption covers a homeowner working in a single family home and its outbuildings that they own and occupy, under MCL 339.5737(3)(g).

Permits for smoke detectors turn on fee lines and the exempt list. The state fee schedule lists “wired smoke detectors” with lighting fixtures and outlets at $6 per 25, and Warren’s form charges $40 to hardwire smoke and CO detectors. A fee line suggests permit work, and the exempt list in R 408.30818 covers swapping a receptacle or switch, not adding a new wired device. Your city’s electrical office can confirm the answer for your job, and our permits guide walks the chain.

A single-station smoke detector is also not a “fire alarm system” under the licensing article, so replacing one does not need the fire alarm specialty license. A monitored or multi-device fire alarm system is a different trade, and the license types guide covers who holds what.

Rental housing is local

What a landlord owes a tenant comes from city rules, not from the statute or guidance above. Two cities publish theirs. Ann Arbor bars leasing a dwelling or rooming unit without a Certificate of Compliance, and the city has adopted an ordinance requiring carbon monoxide detection in all rental properties. Royal Oak’s Building Division inspects all residential rental units under Property Maintenance Code Chapter 556. For any other address, the city or township building office is the place to ask.

Hiring for the job

For a hardwired or interconnected setup, get three answers from the electrician in writing: how many alarms and where, whether the quote includes the permit and who pulls it, and which alarm brand and model, with the date on the back. Check the license on the LARA lookup before you agree to anything, and read how to find a licensed electrician. Our smoke detectors page explains how matching works. We are a referral service, not an electrical company.

A permit fee is not a stand-in for an installation price, and we have not collected Michigan quotes: the smoke detector page carries a modeled estimate.

Walking your own house against the guidance

You can turn the state guidance into a short walk-through. Begin with the sleeping areas, where the guidance puts a smoke alarm inside every bedroom and another outside them. Then count levels, since it asks for a smoke alarm and a CO alarm on each. Look at the garage wall and at each fuel-burning appliance, because those are the places the CO statute names for new work, and measure 15 feet from a furnace, water heater or range before you pick a spot for a CO unit.

Then turn each alarm over. A smoke alarm’s date tells you when its 10 years end, and a CO alarm’s label shows its listing and the manufacturer’s replacement date. Write the dates in your phone or on a card taped inside a closet door, and replace any unit that has no date or is past it. Swapping like for like on a plug-in or battery model takes no electrician. A new hardwired position, or interconnecting alarms so they sound together, is where the electrical work and the permit question begin.

If an alarm sounds

Decide the plan before you need it. Agree on one exit route from each bedroom and one place outside where everyone meets, and test the alarm with the whole household in the room so nobody is surprised by the sound. A chirp every minute or so usually means a low battery or an alarm at the end of its life, which is another reason to read the date on the back.

Leave the house and call 911 if you see smoke or fire, or if a CO alarm sounds and anyone feels ill. Across the United States, the leading cause of residential building fires in 2023 was cooking, at 167,800 fires, with 23,700 from electrical malfunction, according to the U.S. Fire Administration. Those are national numbers and not a Michigan count, and they are a reason to test the alarm monthly, not a reason to panic about your wiring.