Pitbull going through Large Endura Double Flap for Walls

Choosing a Pet Door: Single Flap or Double Flap??

A lot of people question which type of pet door they should purchase, a single flap or a double flap? We’re going to explain the differences, the advantages and the disadvantages for each choice. 

The Difference

double vs dingle flap enduraSingle flap pet doors are the most common choice. One flap makes up this pet door, usually with a type of trim frame on the opposite side. The flap may be located on the inside frame, or the outside frame depending on the brand.

Double flap pet doors are most common for wall installations. Two flaps make up this pet door; one flap on each side. The second flap provides an additional barrier to the elements, increasing your pet door’s insulating capabilities. It also serves an aesthetic purpose, as some people dislike the “hole” look that just a trim frame has in single flap wall installations.

Single Flap Pro’s and Con’s


  • Easier for pets to navigate
  • Less expensive


  • Can appear unsightly to some people from the trim frame side
  • Less insulating than double flaps

Double Flaps Pro’s and Con’s


  • Most energy efficient option for dog or cat doors
  • Finished look from both inside and outside of the doggie door


  • Harder for some pets to use
  • More expensive


If you live somewhere that has any type of severe weather conditions, a double flap might be the best option for you. This includes strong winds, rain, snow, or extreme heat. A better sealing pet door will do a better job at keeping the outside air outside and the inside heat or air conditioning inside! We usually recommend getting a double flap version if you can when you live in areas where you regularly use either heating or air conditioning.

When a Single Flap is Enough

Pet doors vary widely in sealing capabilities. Some have single flap versions that seal just as well or better than other brand’s double flap dog doors. A single Endura Flap pet door is one of such doggie doors and is often plenty enough for even extreme weather.

dogs in snow need double flapWhether your are in the heat or cold, the Endura Flap keeps the weather out. Here is a review by Thermo Panel 3e customer Bob H.:

“Sitting in Maine with a blizzard outside the door. And my Endura flap in my sliding glass door is keeping it outside the door with 40 mph winds blowing straight at it. Glad I switched from that other brand. I would be shoveling snow out of the room by now”

And here is a review from customer Jane P.:

“We installed 2 Endura Flap #10 single flap wall unit dog doors this spring, replacing some Johnson doors that we put in when we built the house in 1990, and are delighted with them. They are on the north side of the house and do a great job of sealing. Air leaked in badly around the doors that were replaced.

We live in Wharton, TX which is about 50 miles south west of Houston. We have had a heat wave this summer. It has been setting records since early June. Most days over 100 degrees. Thanks for the great doors.”


One thought on “Choosing a Pet Door: Single Flap or Double Flap??

  1. John Mahoney

    Thank you so much for talking about how a single flat pet door is usually easier for pets to use. It is important to remember that when choosing one of these you need to consider the climate where you live to make sure you find a durable material. In my opinion, it is always a good idea to look online for what other people use and choose the store where you buy carefully to find the best quality and deals.


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