The 2009 International Residential Code adds a section on carbon monoxide alarms. They are required in new construction residences that have either a garage or a fuel fired appliance. They are also required in remodels of existing dwellings where a permit is required and the dwelling has either a garage or a fuel fired appliance.
When carbon monoxide alarms are required they must be installed outside each sleeping area and in the vicinity of bedrooms. They must also be listed as complying with UL 2034 and installed in accordance with the code and the manufacturer’s instructions.
For practical purposes and with the relatively low upcharge for carbon monoxide alarms it is advisable to buy dual smoke/CO2 alarms for all locations.