There are several considerations that affect the cost and feasibility of installing a pet door into your existing glass door. For budget purposes, the average cost for the new glass and installation will run between $377 and $1,200 and does not include the cost of the pet door that you will order.

Here are a few questions that might help you decide if a pet door is feasible for you:

1. What is the age of your house?

If you have a house that was built after 1980, your existing door likely has dual pane (insulated) glass in it. Most suppliers won't warranty glass that has a corner notch cut into it. Even if your home is older there is a possibility that the doors have been replaced at some time since 1980. Insulated glass is very expensive (approx. $1,000 ) and has no warranty, and you would still have to supply the dog door. People still do it, but you have to agree to those conditions. It’s much less expensive if your existing door is older and has single pane glass in it.

2. What style door do you currently have and how big is your pet?

These questions are related. Is the door that you want to install the pet door in a sliding or swinging door? Sliding patio doors have lower bottom rails which allow a dog or cat with shorter legs to step over the bottom rail. A swinging door will usually have a taller bottom rail which might stop a small dog or cat from being able to step over the rail and through the door. Also most swinging doors will have a fixed (non-swinging) sidelite glass. The pet door can be installed in either glass.

The size and height of your dog makes a difference since a small dog can only step over a shorter barrier (bottom rail of a door) and a larger dog requires a bigger cut-out. Most pet doors have about 4 inches of the pet door at the bottom that is stacked on top of your existing door’s bottom rail. That means a 4 inch tall bottom rail on your door will actually be about 8 inches your pet will have to step over. It is important to measure your pet from feet to shoulders to get a correct flap size and figure how large a cut-out you will need.

We have installed lots of dog and cat doors over the years. But the pet door cannot be installed in your existing glass as tempered glass cannot be cut. So we will have to order a new tempered safety glass with a custom cut-out designed for the door you choose.

There are other possibilities: Using round cut-outs in tempered glass for smaller pets works well and can be less expensive and less likely to break. Using unbreakable Lexan instead of glass can work well for large breeds of dogs or handicapped pets who don’t always hit the opening.

Money saving tip! If you would like Madison Glass to do the job for you we would have to make two trips to your house, one to measure the existing glass and a second trip to go back when the new glass comes in. You can save the cost of those service trips and substantial field labor by bringing the door to our shop. Lead time can vary from one week to four weeks depending on whether your glass is single pane or insulated glass.

If you will email us a photo of your existing door, your zip code, and the size/type of your pet - we’ll be happy to give you a rough estimate. Actual cost might vary depending upon the type of pet door you choose.

We do suggest you save the old door glass so it can be reinstalled in your door when you are ready to sell your house.