Smoke detectors: where Illinois requires them
Smoke detectors in Illinois go in two places. Every home needs at least one working smoke detector within 15 feet of every room used for sleeping [1]. A single-family home also needs at least one on every story, including the basement but not an unoccupied attic [1].
Split-level homes have one more rule. A detector on the upper level covers the level just below when that lower level is less than a full story down, unless a door separates the two levels [1].
Mounting is set by the law too. Each detector goes on the ceiling at least 6 inches from a wall, or on a wall 4 to 6 inches below the ceiling [1]. In a building with more than one unit, the top of each inside stairwell also needs one [1].
Smoke detector batteries: the 10-year sealed rule
Smoke detector batteries changed under Illinois law on January 1, 2023. Any new smoke alarm installed in a home since that date must have a 10-year sealed battery, according to the Office of the State Fire Marshal [3].
Older alarms can stay in place until they pass 10 years from the date they were made, fail a test or stop working [1][3]. Two kinds of homes are exempt from the battery rule: homes built after 1988 that already have hardwired alarms, and homes with wireless connected alarms [3].
Hardwired alarms have their own rules. In a home built or substantially remodeled after 1987, the alarms must be hardwired and linked so one sets off all the others [1]. In a home built or substantially remodeled on or after January 1, 2011, hardwired alarms also need a backup power source, such as a battery [1].
Carbon monoxide alarms: who needs them
Carbon monoxide alarms are required in Illinois homes within 15 feet of every room used for sleeping [2]. One device can do both jobs if it meets the rules for each and its alarm makes clear which hazard it found [2].
The alarm can run on batteries, plug in with a battery backup, or be wired into the house with a battery backup [2].
The law exempts two kinds of homes [2]:
- a home that does not burn fossil fuel for heat, ventilation or hot water, is not connected to a garage, and is not close to another carbon monoxide source
- a home the local building commissioner finds is not close enough to any carbon monoxide source to be at risk
Alarm responsibility: what the owner does
Alarm responsibility belongs to the owner. Under both laws, the owner of a home supplies and installs every required alarm [1][2].
Your town's code can ask for more. The Smoke Detector Act says a stricter local law or building code governs [1].
Home inspection: what the buyer's inspector reports
A home inspection in Illinois checks the alarms as part of the electrical system. The Illinois rules for home inspectors say the inspector must report any non-compliance with the Carbon Monoxide Alarm Detector Act and the Smoke Detector Act [4]. What else the inspector looks at is in what an Illinois home inspector looks at.
That report goes to the buyer. Checking the alarms before you list means you see the same thing first.
How to check your alarms before you list
- Count the bedrooms and floors Note every room used for sleeping and every story, basement included.
- Find each smoke detector Check that one sits within 15 feet of every bedroom and that every story has one.
- Check each one's age and battery Look for alarms more than 10 years past their manufacture date and battery alarms without a sealed 10-year battery.
- Check the carbon monoxide alarms Note whether the home burns gas, oil or another fossil fuel for heat or hot water, or has an attached garage. If so, check for a carbon monoxide alarm within 15 feet of every bedroom.
- Test them Test each alarm, and replace any that do not respond.
What it means if you sell in Illinois
If you are selling in Illinois, the alarms are something you can check yourself before a buyer's inspector does [4]. Walk each floor, count the bedrooms, and compare what you find with the rules above [1][2]. The seller's paperwork side of the sale is in what an Illinois seller must disclose to a buyer.
Thinking about selling in Will or Grundy County? Start with the two steps below.
Complimentary Home ValuationSchedule Your Seller Consultation
