Winter is coming and the heat is being turned on. Every hole in exterior walls, including those for light switches, outlets, doors, windows and ceiling light fixtures, is an invitation for cold air to get in and heated air to get out. As much as 25 percent of your heating and cooling energy can be lost through these leaks. Put your hand in front of a light switch or outlet. If it feels colder than the wall around it insulation is required. Light a candle and hold it near your door and window jambs. If the flame blows toward you cold air is getting in and weather stripping is required. Look under the sink where the drain pipe enters the wall. If it is not completely sealed warm air is escaping.
Fortunately, these fixes are inexpensive and easy to put in place.