How to Install a Dog Door in a Glass Door

Having a doggy door installed in your doors and walls benefits you and your pup! To start with, you don’t have to be a doorman for your pet every time they have to go outside to answer the call of nature. Dog and cat doors can be conveniently installed into all kinds of walls and doors in your home and they will continue to be useful for a lifetime.

endura flap thermo panels

You can even install a dog or cat door in windows if you don't have an available wall or door with an in glass pet door. An exterior doggie door in glass door is a convenient solution that often installs tools-free! Window cat doors install similarly to patio door with dog door options, often not requiring any tools (patio door cat flaps are also easy installs too)!

Dog doors are one of the best gifts you can give to your pets. It gives them the freedom to go in and out of the house without troubling anyone. Keep reading for tips on how to install a sliding glass dog door!

Dog door installation  in a glass door is not as simple as it sounds. If you take a drill and start drilling holes in your glass door, you are simply going to crack it completely and your expensive door will be of no use. Even though it can be heavy duty, glass is still a fragile material! You will have to look into dog door designs in order to determine what options best fit your need.

There are patio pet door options that will install without any tools (known as patio panels) such as the high quality Endura Flap Thermo Panel 3e. Simply insert the panel with a built in pet door into your sliding door track and door frame and you're good to go! For an option that mates with your current lock, and "in the glass unit" replaces an existing pane of glass in your sliding door with a brand new one that has a pet door pre-installed.

black dog using endura thermo panel

The first thing to do is check if the door has a single-pane or a double-pane glass installed in it. A single-pane glass can be easily cut as it is not very thick. However, if your glass door is made up of a double-pane glass, it is challenging and the process takes time.

The double-pane glass has to be taken care of and you have to take further steps before you can actually install a dog door in it. The first step is understanding the glass door you own. Before you start hammering it, it is important that you work according to the glass. The first step can be done simply by finding an experienced glazier who has knowledge about your door’s glass and glass panes.

If you have an in-glass project, then offers two excellent services. Whether it is for your glass door or for your glass window, they will do it all for you. Pet Doors also offers a service on their website which will help you find a qualified glazier who has experience in specifically dealing with some of the best pet doors in glass doors, even if you want a french door with dog door.

If you want to find a glazier through, simply head to the website and check out Independent Professional Pet Door Installation to find an approved local installer in your area. The website will ask you about your location and with find you an installer according to the state you live in. After getting multiple options, you can select the one that’s closest to your city and leave the rest to them. Other ways of finding a glazier involve using Yelp or Google. You can search on any site and find the most convenient option for you.

A dog with the freedom to go inside and outside whenever it wants

The reason why finding an experienced glazier is so important is because all the following steps are linked to the information they are going to provide you with. The glazier will measure your glass and give you the exact dimensions. They will also measure the thickness of the glass and tell you other relevant information. Another piece of information that is important to know is about any tints on the glass, like Low-E coating and others.

The other piece of information that you will require is the size of your pet and the size of the dog door you are planning to have made. Measure your pet's width and add at least 1 inch to each side for a comfortable fit of the door flaps. For the length, add at least 1 inch to the height of your pet from ground to shoulders. This will give you a well-sized dog door that your pet will be able to use comfortably. The pet measurements are extremely important as you don’t want your pet to fit comfortably through the door for their whole life!

Once you have finalized all the measurements and have the information about the glass in your door, you can place an order on You will select the glass type, flap size, LoE coating or not, and the step-over height and then place your order. Once your order has been placed we'll follow up with a form where you can fill out your specific glass measurements and send them back to us.

border collie using endura thermo panel

Generally, an order can take up to 3-4 weeks for production since the glass is made to fit perfectly to your door. As soon as the glass is delivered to you, you are ready for glass installation of  your new glass door with a dog door in it. You can now call the glazier again to finish up the project. The last task is pretty simple as the glazier only has to swap the current glass with the one you have ordered (just like fixing a pane of broken glass!).

We hope you and your pet enjoy thoroughly enjoy your new In the Glass unit!

Stephen Daily

Written by

Stephen Daily

The Team is dedicated to providing the highest quality pet doors. As dog and cat lovers ourselves, we aim to write about the topics that matter the most to you and your furry friend. If you have any questions, please contact our customer service team. 🐶🐱

The Team is dedicated to providing the highest quality pet doors. As dog and cat lovers ourselves, we aim to write about the topics that matter the most to you and your furry friend. If you have any questions, please contact our customer service team. 🐶🐱


  • Hi Julie!

    There are two main options for sliding glass door dog doors. We have pet door panels like this one that would not require working with a glazier and is easily installed into the track of your sliding glass door and secured with either a dowel in the track, slider lock, or charley bar. The “In The Glass” option would replace your entire sliding glass door glass and you can click on the different options on the product page to get an idea on the pricing for your glass door. This method would require hiring a glazier to measure and install your glass.

    For both options, you would want to measure the height of your dog from top of shoulder to floor to determine the size of the pet door that would best fit them. The stepover height (about 3" – 5") should be no more than 1/3 of the dog’s height and the top of the pet door opening should be at least 1" taller than your dog to prevent scraping of the back.

    Adult Lab Retrievers are about 22" – 24" tall according to Google, so we would recommend either a Large or Extra Large flap size for either option above depending on your dog’s specific size.

    Please email us at for more assistance for your specifications! :)

  • Hi ,
    Can I get a quote on a 27″×73″ double paned glass door installation with a doggie door (for a large adult lab retriever). I would like another double paned glass panel as well.

    Just not sure if it is worth replacing the entire door.
    Thanks ,


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