Window Caulking and Door Weatherstripping
Keeping a home well sealed can tremendously improve the heating efficiency. The most common spots for air leaks are around the windows and doors seals. Visually check the caulk seal around the outside edge of every window for gaps. Use a putty knife to remove the damaged seal and insert new caulk. Cracks will reappear if the caulk is applied too thinly.
Inspect the weatherstripping around the perimeter of exterior doors. Replace any damaged areas with new material. Replace the entire seal, if required. Feel for drafts by running your hand around the edge of each door. If the weatherstripping is in good shape and there is still a draft, there might not be enough material to bridge the gap. It is possible to layer the strips on top of each other to seal larger gaps.