I inherited a dog door when moving into a new house and soon realized that it was much too drafty for my energy conscious needs. I have been switching incandescent bulbs to CFL's, weatherproofing and upgrading the R rating on insulation in my new home, so why not work on that doggy door?
The door that came with my new home, is a Petsafe Easy Fit. It's a budget door that's easy to install and I guess for the previous owner it was probably one of a limited selection at the local pet store.
The flap that was on the door was at least 2 years old and was no longer sealing out the draft. I thought seriously about purchasing Petsafe's Extreme weather dog door, but it was priced a bit out of my range, and I love a DIY project. I decided to build my own insulated door, using a similar three flap design.
The replacement flap for the Easy Fit door was available at Amazon for a good price and had many good reviews. It fits several models of Petsafe doors and various sizes are available. I ordered it to function as the inner flap of the weatherproof dog door. If you have a different model pet door, see if you can find a replacement flap for your specific model/size.
Now to the fun part. I proceeded to take off the original flap and give it a good cleaning. I also soaked it in some hot water and then placed it under a heavy book to reshape it. I took a microfiber towel from a bulk pack bought at Costco and cut it to fit the exact dimensions of the door flaps, minus 1/8" on each side. Any old hand towel would work for this purpose, I just had plenty of these available. The important thing is to be able to create some airspace between the two flaps.
I sandwiched the microfiber towel between the two flaps, lined everything up perfectly and mounted all three pieces to the original door frame. The replacement flap had a raised surface at the mounting point, so I flipped this around backwards to leave about 1/8" inch of airspace between the flaps, for better insulating properties. This is what the finished project looks like:
Hope this helped someone out! Please click my Amazon links if you decide to purchase from there and it will help me continue to post these DIY money saving project tutorials.