DIY Insulating Doors

Check the door and how it sits on its hinges. Use a level on the top of the door to ensure it is balanced and not sitting at a slope that can create an energy gap. Remove the door and readjust it if necessary.

Look in the door frame hole where the door locks. Spray foam insulation in the hole if the hole goes well beyond the latch requirements. Insert a small amount as the foam will expand. Keep enough space for the lock latch. If the foam overruns the space, wipe away as much as possible before it dries then file any remaining dried insulation down until the lock fits once again.

Install new weatherstripping along the bottom of the door. If the door has an existing strip that is worn or damaged, replace it. Place foam tape along the door frame for further insulation. These adhere with a sticky backing.

Place a welcome mat outside the door that extends the width of the door. It won't block a weather gap, but it will absorb some of the weather to slow the incoming draft.

Install drapes over doors with glass panels. Glass is not as good an insulator as wood. Heavy drapes help retain heat.

Roll thick towels and set them along the base of the door when you are home to prevent drafts and keep heat in the home.