Energy Efficient Pet Door

After trying to build my own energy efficient, weatherized pet door (see my article here on how to build a pet door), I got fairly far along on a prototype, but then got a chance to try an energy efficient pet door from Freedom Pet Pass. By the way, I have no affiliation with this company and no reason for bias either way on my thoughts about this door.

Here it is, The Freedom Pet Pass Door! Note: click on photos to see them larger.

In fact, Brian from Freedom Pet Pass, made a comment at the bottom of my article titled "How to Build a Pet Door", and mentioned that he had approached the leaky pet door problem about 5 years ago, which lead to the development of the Freedom Pet Pass Dog Door. We then had a chat on the phone and shared our interest in energy efficiency, and the need for high quality, draft free, pet doors.

Pet doors are often overlooked in air-sealing a house, but yet they can be a major contributor to air leaking into your house. If you live in cold climate, your going to want to insulate the area where your foundation meets your first floor. I have an article about that here, along with an explanation of "the stack effect" and how leaks lower on a house are subject to inward, cold air pressure, resulting from hot air leaving the top areas of your house.

I insulated my basement rim joists, but there it was, staring me in the face, a old leaky cat door. That old door was so leaky it was like having a permanent hole to the outside, leaking all day long. That's how I got where I am now with my interest in energy efficient, air sealed, draft proof, insulated cat/pet doors.

What follows is a complete review, and my installation steps (your steps will vary) of the Freedom Pass Pet Door, in one of my basement windows (two panes down from my home made prototype).

If you missed my "How to Build a Pet Door" article, this basically is where I stopped in construction. It's a great prototype, but... my design called for one in-door and one out-door. While cheap, workable, and improvable, I've not had time yet to build the out-door yet! Freedom Pass Pet Door to the rescue!

Freedom Pass Pet Door

This is the side that faces out to the elements. The first thing you notice is the high degree of craftsmanship. I've been to all the local big-box pet stores and home depot to see their offerings, and those trips are what inspired me to make my own cat door. What's out there is so crummy either in construction, or it's ability to weather seal, that you wonder if the manufacturer gave it much thought at all.

Times are a changing, and with heating prices fluxuating, and the renewed interest in "Green" living, manufacturers had better raise to current consumer demands. This door on the other hand, clearly had two objectives in mind, bullet-proof construction, with real draft stopping ability.

Here's the other side, that I realize I shot upside down, but it gives you a good look at the sturdy construction of the flap screw anchors. The hole there is used in their locking version, and does not compromise air-sealing in the non-locking version.

Here's a close up of the top. Again, it's clear this thing is tough, and designed with great attention to detail.

Here's a shot of the bottom featuring a rugged hard plastic "chew guard" over the bottom of the exterior flap. The design and engineering fits in the family of high end, tight design, the kind of design that makes you think of BMWs, or other precision engineering. This door has it's roots in function rather than form, but when function is done well, beautiful form will follow.

And here's the guts of the operation, multiple air sealing magnetic strips. The gap between the lower left magnets is intentional, as it is a weep hole to let moisture out between flaps.

And here is the magnet system seen from the other side. You can see there is a complete seal all the way around, which is something I don't think I saw on other products. That concept was also part of my initial design for my home made door, but I wasn't quite able to figure out magnets that would attract one another, and "other issues".

My Installation of the Freedom Pass Pet Door (your installation will vary depending on whether you are installing a door mounted version, a wall mounted version, etc.)

Here I've removed the window pane, and have started to chip away at the very stubborn old window glazing.

Using a screwdriver, a putty knife, a utility knife and sandpaper, I was able to remove most of the glazing.

I've always have trouble with measuring tapes, so instead, I taped together two paint stirrers and marked the width needed at the bottom and top of the pane. The cat door frame was too wide for my needs, but the height was perfect.

My window frames are old and the top width needed to be about 1/8" skinnier than at the bottom.

I'm transferring my measurements onto the cat door frame.

Using a t-square, I'm marking the sides to saw off.

And now it's operation time, all clamped and ready to cut.

The frame material is some sort of plastic composite and is easily cut with a jigsaw. That's another nice feature about this door, you can easily trim it to fit your needs.

Here I'm applying a bead of exterior grade window and door caulk to the exterior of the window frame.

I've put the pet door out the frame and then drawn it tight up against the outside of the window frame. The caulk squeezed nicely into all voids, and with my finger, to smooth it out, I was able to make a neat airtight bead. If I had a dog I would do more to hold the door in place, but I believe the caulk will be all I need for our gentle cat. I've not caulked the outside yet, but I will.

And now the royal subject has arrived. She has studied the new developments and is questioning why I keep messing with her cat portals.

And after I show her how it works, whammo, she's in! And... I don't think she's figured this out yet, but this door goes out too! What an improvement over my design! haha

For those that are wondering, the basement window is not a huge leap to the ground. The basement stairs make the distance short, and there's a hard to see, but wide ledge, just below the window. Also, the door to the basement stairs has a simple interior grade cat door.

More to come on this pet door's energy efficiency and it's draft stopping abilities. Stay tuned!

The flap shown here is clear and is in development now, but not currently on the market. The available flap material is an abrasive resistant, highly flexible, thermal canvas coated, marine grade material, designed for extreme weather.

Freedom Pet Pass: Energy Efficient Pet Doors

My Standard Disclaimer: This is what I did. This does not mean this is the best way, the right way, to building code, or even safe for your needs. So you are on your own with your project. I make no promises about the information presented here. I'm just a do-it-yourselfer, not a professional at all, sharing my story. So if something goes wrong with your project, you are on your own. Good luck, and have fun!

All content and photos, copyright 2009, Dover Projects
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  1. Isn't there anyone out there who makes nice, quality doors with pet doors built in? If not, why not? Seems like a good business.

  2. I don't know of anyone doing this currently. Interesting idea for sure.--Peter

  3. Hi! I need to replace my store bought cat door and make my own since one of my cats is just too fat for the doors on the market. I was wondering where I can find the flap material. Lowes/Home Depot? Also, where to buy the magnet strips.
    Thanks for the article and your help!

  4. That's a good question. When I was researching making my own cat door, (see link in the list of links above), I couldn't find anything that was good material for a flexiable cat flap, that's why I used the solid, plexiglass-like material. My project never came to a final version, and a good sealing cat door is quite hard to make.

    Perhaps your cat could use a small doggy door instead? Those doors would of course be bigger and heavier, so the cat would have to have the desire/ability to open a heavier door.

    I just did a quick Google search for "Fat Cat Pet Door" and got this link (I have know idea if it's a good door or not:

    The flap on the photo doesn't look very big, but perhaps there are others for fat cats online.

    Let me know how it works out.--Peter

  5. NEW!!! DOVER PROJECTS ON FACEBOOK! Join in with your DIY spirit! Click on the BIG blue box for "Facebook, Dover Projects" in the right column above! See you there!--Peter

  6. I followed the link to freedom pet pass you have there and it is one of those internet catch alls. I THINK the real link is

  7. I am confused. Which cat door did you buy from Freedom Pet Pass? I didn't see one for windows, only doors and walls. Does it matter?


Please leave your questions or comments here. I love to get feedback. You can do so without an account or user names and passwords, etc. Just select "Anonymous" next to "comment as". Thanks!--Peter