Here is some general information regarding the New WI carbon monoxide detector law:
The governor signed into law a bill that requires carbon monoxide detectors in all homes by February 1, 2011. The detectors have been required in all new and existing multi-family units. The law extends the requirement to all one and two-family homes. For the owners of one and two-family residences the law does not have a fine or penalty associated with non-compliance (similar to the smoke detector law), but non-compliance will show up on home inspections, so sellers must be aware of the new requirements. I think there was an attempt to enact this requirement as an emergency rule several years back but it must have been put on the back burner, so-to-speak, until lately.
The law requires carbon monoxide alarms to be installed in the basement and on each floor (except an unoccupied attic) of all newly constructed and existing homes. Dwellings with no fuel burning appliances (furnace, fireplace, water heater, garage heater, etc.) and do not have an attached garage are exempt. For all new construction the alarms must be hard-wired, but for existing one and two-family homes battery powered alarms are allowed and plug-in alarms are acceptable for existing multi-family units.
Here is a link to the actual bill: Senate Bill 415