Pet Doors for Windows

Installing Pet Doors in Windows

How does a dog or cat door for windows work?

Window cat flaps and doggy doors for windows are panels that sit in the track of your sash window or sideways sliding window that has glass on one side and a pet door on the other. Your window will slide down to rest on the top of the cat flap window insert for sash windows, or slide up against the side of a pet door in a sideways sliding window. Basement window installation is possible as well, as we have had customers remove the current window to replace it with the sash window. Some of the best cat flaps for windows out there even have special features, such as microchip sensors. 

How is the pet door window insert secured in my window?

Most window mounted cat doors such as the Petsafe Cat Sash have some type of pressure system at one end that expands to the width of your window track and then is locked in place so that the panel cannot be removed from the track. Some dog doors for windows and window cat door panels do require you to drill a hole through your track to secure the panel, but most are no tools required.

How do I lock my window pet door?

If you want to semi-permanently secure your window cat flap or window doggie door in place against your pet door, you can toenail in a screw above the window to prevent it from being able to open. A cat door window insert can also be further secured with a Charley Bar. You can also check out our full selection of doggie door locks. 

Additional Information

Manufacturer Return Info

There are many factors to take into consideration when deciding to install even the best cat door for windows or the best window doggy doors. Window installation is a good option for those looking for the convenience of installing a cat flap door but hesitant about making any permanent alterations in their home.

We offer many different pet door for windows options to fit many different needs and budgets. We are always here to help you find a cat door for windows solution that works for you. If you have any additional questions that were not addressed in the FAQs, please feel free to email us at customerservice@petdoors.com

How to Measure for a Sash Window Pet Door

Pet Doors for Windows FAQs

Will my window dog door keep out the weather?

Some cat flaps for windows guard against the weather better than others. A well-made pet door for windows will be weather-resistant and durable enough to withstand the elements! Top choices for weather-proof doors would be the Thermo Sash or Hale Omni Sash pet doors, which feature weather stripping that lines the flap opening for maximum energy efficiency. A great low-cost option is the Whiskers & Windows Cat Door for Sash Windows from the Whiskers & Windows collection. 

Some sash window pet doors rarely require replacement door flaps, while others might need a new flap as often as once a year. Higher quality dog doors in windows may not require replacement parts for your pet’s entire life, while less expensive pet doors might need new flaps after every rough season. If you don’t want to replace flaps, investing in one of the more expensive pet doors can pay off in the long run.

What are some specific points that I should think about when considering a doggie door window insert?

Is the window close enough to the floor that my pet can easily and safely access the pet door? If not, do I have a way to put steps or a ramp to make it accessible? The same consideration applies to the outside of the window as well, say if your window leads out to a deck where they would have to step up or down to get through. Is insulation quality a major concern when choosing your sash window pet door? Or is keeping other animals out a bigger issue? The window track width is also important, as it has to be wide enough to accommodate the framing of the sash window. Most sash windows will require a track that is at least 1” wide. However, the Hale Omni Sash can be modified to fit widths down to ½”. Knowing how high you can raise the window in order to install the door is another piece of information you will need.

Can I lock my window with the pet door installed? What kind of lock will the pet door include?

A sash window pet door may not include a lock at all, as there are two very simple methods for locking the window. If you want the window permanently locked, after installing the sash window pet door, simply install a screw part way in just above the lower window in both tracks. The window can't be raised from the outside, and the screws cannot be removed from the outside either.

If you want to be able to raise the window on occasion (for cleaning the outside, say), the simplest way is to cut two dowels to stand inside both window tracks just above the window and reaching to the window frame. These will block the window from being able to be moved upward! The window can't be raised when the dowels are in place but can be raised when the dowels are removed.

Can I switch the side the pet door is on with the Thermo Sash 3e? How?

Yes, you can switch the side the pet door is on. You can start by removing the screws on the top and bottom, then sliding the flap assembly out. Once it is removed, you simply flip it upside down and slide it right back in. Next, you put the screws back in, tighten them all down, and you're finished.

Can I flip the side the pet door is on with Ideal pet door models?

You have to specify on the order where you want the door installed. You should really make sure this is where you want the door to be because once the Ideal sash is built with the door to the left or right, it cannot be changed since it is a custom order and therefore non-returnable. Another issue is that the door will not be all the way to one side in the instance of the Ideal Fast Sash. This is because the thumbscrews that adjust the spring load on the sides would interfere with the closing cover, so it would end up looking something like this:

Can you make a Thermo Sash smaller than the 22" adjustment?

Not generally, if you want glass in it. What you can do is trim down the spring-loaded piece on the side, to give you an extra ¾” of compression so that you can get it down to 21-¼”. If this is still not enough, then give us a call with your dimensions because we might be able to build one for you that only uses metal and not glass. This may not seem as nice aesthetically, but it will get the job done, and you'll be very happy with the Endura flap choice.

Is it easy to install a pet door for a window?

Your sash window pet door should come with a weatherstrip designed to seal this gap up again. Be sure the particular pet door you're interested in has this included with the purchase. We include this item, also called a draft stopper or center post weatherstrip, with our Thermo Sash 3e.

What are the major types or styles of sash window pet doors?

Some are available with dual pane glass and high-quality flap designs. These will be more expensive but will provide much better performance in extreme temperatures. Examples of these are the Thermo-Sash 3e and Hale “Omni” for Sash Windows. Sash Window pet doors with single pane glass and thinner flexible vinyl or polycarbonate rigid flaps will not perform as well but are a more economical choice if you are on a budget. If this less expensive model is what you are looking for we offer the Ideal “Fast Sash” and Ideal “Cat Sash”.

What is meant by “Sash Window?”

A sash window or ‘double-hung’ window consists of two window units, one above the other, in separate tracks. The bottom unit slides up and down in the inside track, and in the case of double-hung windows, the top unit may slide in the outside track as well. There may be a locking device in the center where the two window frames meet.

How is a pet door installed in a sash window?

This installation can be very simple, and depending on the type of track may require no tools. The lower window is raised, and the pet door is positioned in the track beneath the window. Then the window is closed down on top of the pet door sash.

What will I have to do with the screen on my window that I want to install a pet door in?

The screen must come off in order to allow your pet to enter and exit freely. Your screen should be held in a frame that can pop off the outside, and you can store it for future use.

Do you have any pet door sashes that are electronic?

Yes, the Ideal “E” Cat Electronic Cat Door is electronic, but it is for cats only, and it only controls one way (magnetic closure). This means that it wouldn't be a good choice if you wanted to keep one cat inside and let another in and out. Also, it isn't raccoon-proof, because with the magnetic doors they can get their little nails under the flap from the outside and pull it backward, simulating something going out, and sneak inside under the flap.

Do I need tools to install the Ideal Sash Windows made with dual pane glass?

No, they are made with ⅛” thick single pane glass.

Can I lock the Ideal Fast Sash for Windows?

Yes, it comes with a locking cover that slides in from the top of the sash window. You will need to double-check to make sure that there is no lip sticking out on the frame that closes down on top of the sash pet door because that would get in the way of sliding in the cover.

Do I need tools to install the Thermo Sash?

No, there are no tools required to install the Thermo Sash, but just like with the Hale, you can drill in a screw above the sliding window for security.

Do the Ideal Sash Windows come in multiple colors?

The Ideal Sash window only comes in white.

Do you offer different colors for sash windows?

We do in the more insulated models. For the Thermo Sash we have white, bronze, and satin (aluminum), and in the Omni, we have the same options and an additional choice of Arizona Beige.

Ouch! These are expensive, any way to make my own?

Sure. Here's how (Beware: It's going to sound harder than it is)

Start with a piece of plywood or Lexan cut tall enough to accept the pet door and wide enough to extend to a shade less than half the depth of each track. This dimension will allow the panel to be inserted into the track. When one end is all the way in, the other end will just clear the opposite track wall. Then you center so that both ends protrude into the track halfway.

Run adhesive-backed weather-strip along the top and bottom of your panel to ensure a tight seal. From the outside, drill a hole in each corner at an angle into the window track. Use a wood or metal screw in each corner to hold your material in place. Install a door mount type pet door of your choice into the wood or Lexan panel you've fastened in place.

If necessary, shim around the hole to the thickness required by the pet door. You'll want to install the pet door before fastening the panel into the track. If wood, paint to match your decor. Lexan looks like glass, so no painting is required. Close the window on your pet door and decide if you need a lock (see above).

If the opening of your window has broken the seal between the two window sections, weather-strip that gap, you can find the weather-stripping you need at pet door weather-stripping.

Bingo! You're all done!

Do you drill them in?

Nope! All of them are tension mounted, however, you can screw them in if you choose to make it more semi-permanent.

How do I keep other cats out?

If keeping other cats out is a priority, you should get an electronic or microchip cat door. A great choice is the Thermo Sash 2e with Sure Petcare. This window sash features the largest microchip pet door available, functioning as a large cat door that works for small dogs.

Can you install it inside sliding windows?

The Custom Endura Flap Thermo Panel 3e can be made for side sliding windows.

Is it easy to install?

Most of the Sash windows involve loosening the thumbscrews, setting the sash in place, and letting the topper spring into the frame and then tightening the thumbscrews on the inside of the house.

The pet door is not wide enough, but only by an inch, what can I do?

If you have a pet insert for your window from Endura Flap or Ideal Pet Products, you can add a width extension to make your panel fit your window. You can cut a board to the height and length you need, and slide it into the adjustment channel on either side.

The sash pet door is too wide by less than an inch, what can I do?

If you have a pet insert for your window from Endura Flap or Ideal Pet Products, you can trim off about 3/4" from the edge of the spring-loaded adjustment pieces.

What do you do if the knobs hit the window track so it sits unevenly?

You can add weather stripping or shims into the track where the pet door is installed. What this does is kick the panel out just enough at the bottom to straighten it out, preventing the bottom of the pet door from going into the jamb far enough to bump into the panel.

What is the difference between Ideal Cat Sash and Fast Sash?

The Ideal 'Cat Sash' has a rigid flap and a 4-way locking mechanism. The Ideal 'Fast Sash' has a soft flap with a locking cover that you can slide over the pet door to prevent entry or exit.

What is the thickness?

The thickness of the track is the space that your window actually slides in; it's usually around an inch thick or so. Make sure that there is enough thickness to fit the sash that you are looking to purchase. The thickness of sashes can be found on the additional information tabs of the specific product.

It is the Hale Omni Pet Door for Sash Windows, Giant flap at a whopping 15 1/2" wide x 27 1/2" high. You will need to be able your window high enough (approximately 32") to accommodate this sash.

I don't see a short cat door sliding window option that will work for my height, what are my options?

We can build a custom Endura Flap cat door for sliding windows to match your needs.

What dog door for sash windows do you offer?

We recommend the Endura Flap Thermo Sash which offers four sizes for a pet door in a window

I need an inexpensive pet door for window insert with an easy locking mechanism, what should I order?

We recommend the Ideal "Cat Sash" Cat Doors for Sash Windows. It has a 4-way lock that is simple to use.

Do you have a Dog window pet door?

Yes, the Thermo Sash 3e comes in four pet door sizes to fit most dogs.

I need to know how to measure window sizes, can you help?

Yes! Every window is different and may take a little finessing for a proper fit. The window track is what holds the Pet Door Sash Panel in place. You will want to measure from the deepest part of the left track to the deepest part of the right track to get an accurate measurement. Many Sash Panel designs allow being trimmed up to one inch narrower. Also, width extensions are also available. You will also want to consider how high the window will open. The panel height is determined by the flap size you choose. Once you have determined the Sash panel size, a good test is to replicate the Sash Panel size in a piece of cardboard and complete a fake install, without bending, to ensure it will fit. Our Customer Service team can help if you have questions.

Do you have a question that wasn't answered? If you do, please email it to us at customerservice@petdoors.com!