Gaps around windows and doors can make it tough to keep your house warm in winter. Caulk around windows and install weather stripping around doors as needed. This minor and inexpensive task can help you save on heating costs.
If your windows and doors are older, they may be inefficient single-pane windows or uninsulated doors. Consider upgrading to double- or even triple-pane windows and insulated doors and garage doors to boost the energy efficiency of your home.