Things You'll Need
- 1-inch pine trim boards
- 1/4-inch plywood
- Jigsaw
- Foam-insulation board
- Razor blade
- Glue
- Small magnets
- Scrap steel
- Screws
- Hinges
- Screw gun
Instructions
Determine the location of the proposed dog door. A place in the middle of an existing door is normally best and easiest to work with.
Use the jigsaw to cut a hole appropriately sized for your dog (i.e., the larger the dog, the larger the hole will need to be).
Build a frame around the hole you just cut with the pine trim boards.
Cut a piece of the plywood to match the hole you cut in the door. This will serve as the dog door. Lay the plywood door on the foam insulation and use the razor blade to cut around the perimeter of the door. Glue the foam insulation onto the plywood door, and then install the hinges onto the plywood portion of the door.
Glue the magnets on the opposite side of the plywood door as the hinges, and then mount the scrap steel in the bottom of the hole you cut in the normal door. Use the included hardware to attach the hinges on the plywood door to the top of the hole in the normal door, so you have a swinging plywood dog door. The magnets will catch on the scrap steel metal and hold the door closed when it is not in use, and since you insulated the dog door, a minimal amount of cold air will be able to get in the house.