Winter is a good time to inspect your home for leaks. When it’s cold and the wind is blowing, walk around the inside of the exterior walls and feel for drafts and cold spots. You may be able to find and fix the trouble spots yourself. Caulk around windows and doors. Spray foam large openings with Great Stuff. Remember, every little bit helps.
There are professionals who can help if you are not able to see and seal the places where your home is not sealed or insulated properly.