- Install weatherstripping around the edges of the door.
- Install insulation kits. These kits come with insulation panels that fit around the door and are held in place with adhesive.
- Apply spray foam insulation around the edges of the door and between the panels.
- Install a door sweep at the bottom of the door to seal any gaps.
- Replace any worn-out or broken hinges or tracks.
- Hang a thermal curtain to further reduce drafts.