Dept. of Commerce: CO detectors required statewide beginning February 1

Contact: Tony Hozeny, Department of Commerce, 608/267-9661

MADISON—All one- and two-family dwellings will be required to install carbon monoxide (CO) alarms to comply with changes in Chs. Comm 21 and 28, Wis. Adm. Code. The rule changes are in response to 2009 Act 158, enacted March 10, 2010, and follow a similar requirement for multi-family dwellings.

“According to the American Medical Association, CO poisoning is the leading cause of accidental poisoning in the US,” said Department of Commerce Secretary Paul Jadin. “CO alarms have shown their effectiveness in alerting occupants to the presence of this poisonous gas.”

One-and two-family dwellings for which a building permit is issued on or after February 1, 2011 require carbon monoxide alarms that are interconnected and directly wired to the dwelling’s electrical service, with a backup battery supply. Existing dwellings may use battery-powered, stand-alone alarms. The alarms must be installed in the basement and on each floor level except the attic or garage. The law applies only to dwellings that contain CO sources. CO sources may include, but are not limited to, garages, heaters, fireplaces, furnaces, appliances or cooking sources using coal, wood, petroleum products, or other fuels emitting CO as a by-product of combustion.

The rules are available at

The requirements for multi-family dwellings are available at