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Imagine if your cat could decide for itself when to go in and out without needing you.
But installing a cat flap in the window can be tricky and carries the risk of damaging the glass.

The solution is a professional installation that gives your cat freedom while maintaining the integrity of your window.
In this article, you will learn how to choose the right cat flap and install it safely in your window, what tools you need and how to ensure the safety of your four-legged friend after installation.

Why a cat flap in the window is useful

A cat flap in the window is useful because it allows your cat to move between inside and outside as it pleases . This promotes your cat's independence and well-being as it can follow its natural instincts and have its own schedule.

Installing a cat flap in the window offers several advantages:

  • Safety : The cat can quickly escape dangerous outdoor situations.
  • Convenience : You don’t have to constantly open or close the door.
  • Hygiene : Reduce the risk of your cat bringing vermin into the house as they do not enter and exit through main doors.

Additionally, a window cat flap can be aesthetically pleasing and blend seamlessly into your home. With a professional installation, you can ensure that the integrity of the window is maintained while creating an access point for your cat, giving them more freedom.

Choosing the right cat flap

Choosing the right cat flap is crucial for your pet's happiness and your convenience. Different types of cat flaps offer different features, from simple manual flaps to those that work with a microchip or magnet. Consider what works best for you and your cat so that they can enter and leave the house independently and safely.

Here are some points to consider when making your selection:

  • Size and breed of your cat : Make sure the flap is big enough.
  • Location : Consider where the flap will be installed and whether the window material is suitable.
  • Functionality : Do you want the flap to keep out strange animals? Then a flap with microchip recognition might be useful.

It's also important to keep an eye on your budget . Manual flaps are often cheaper, while microchip or magnetic flaps may cost more but offer additional security. Also, keep in mind that some flaps may require professional installation , which adds extra costs, so choose a flap that fits both your needs and your budget.

Instructions: Installing a cat flap in the window

Installing a cat flap in a window can seem complicated at first, but with the right instructions it is definitely doable. Before you begin , you should make sure you have all the necessary tools and materials to hand. This usually includes a tape measure, a marker, a saw or glass drill, silicone sealant and of course the cat flap itself.

First, you need to determine the exact installation location and mark the size of the flap on the window where you want it. It is important that the flap is not too low so that there is no draft, and not too high so that your cat can reach it easily. The optimal height is usually just above the floor level of your cat when it is standing.

Here are the next steps:

  • Prepare the cutout : Use the tape measure and marker to mark the exact dimensions of the cat flap on the glass.
  • Cutting : Carefully cut out the piece using a saw or glass drill. Always wear safety glasses and gloves for protection.
  • Inserting the flap : Insert the flap into the cutout and secure it according to the manufacturer's instructions.

Once the flap is in place, you should seal all edges with silicone to prevent water from entering and to create a smooth surface . Make sure the flap is firmly in place and does not have any sharp edges or corners that could injure your cat.


Finally, it is important that you check the functionality of the cat flap. It should open and close easily and your cat should be able to go through it without any problems. If everything is installed correctly, your cat will now have the freedom to enter and leave the house as it pleases, while you have the security of knowing that your window is still well insulated.

Frequently asked questions about installing a cat flap

When installing a cat flap later, questions often arise that you may have already asked yourself. A common question, for example, is whether the installation will affect the security of the window . The answer is reassuring: as long as the installation is carried out correctly, the stability of the window will be maintained. However, it is important that the flap is not installed too close to the edge of the glass so as not to weaken the structure.

Another concern is whether the cat flap can cause drafts . Modern cat flaps are fitted with seals and brushes that minimise drafts. Here are a few points that will help reduce drafts:

  • The flap should have a seal that closes well.
  • Brush strips on the edge of the flap can help keep the heat inside.
  • The flap should be positioned correctly to avoid direct wind.

Finally, many people wonder whether any type of glass is suitable for installation. It is important to know that safety glass cannot be reworked and therefore a new glass with a pre-made cut-out is required. With standard glass, a specialist can create the cut-out on site. Remember that the thickness of the glass plays a role and special flaps may be required for thicker or insulated glass.

Ensuring safety after installation

After you have installed the cat flap, it is important to ensure the safety of your home and your cat . Check that the flap closes properly and has no gaps that could allow unwanted guests in. There are special locks and latches for cat flaps that offer additional protection. Also make sure that the flap sits firmly in the window and does not wobble or rattle, which could indicate unsafe installation.

For your cat's safety, you should make sure that it can use the flap without any problems. Carefully train your cat how to use the flap and make sure that it cannot get caught. Some points to keep in mind:

  • The flap should be adjusted to the size of your cat.
  • Make sure there are no sharp edges.
  • Check the functionality of the flap regularly. This will ensure that your cat can go in and out safely and independently .

Installing a cat flap in different window types

Fitting a cat flap into your home depends greatly on the type of window. For standard windows, a professional can often make the cut-out on site. However, for safety glass or double glazing , this is not possible; new glass must be ordered with a pre-made cut-out. Similar guidelines apply for balcony doors, although the size and opening mechanism of the door may require additional consideration.

There are a few important points to consider when installing in different window types:

  • The thickness of the glass plays a role and can influence the type of cat flap required.
  • Custom manufacturing is often necessary to ensure a perfect fit and secure installation.
  • It is advisable to contact an experienced craftsman to ensure that the integrity of the window or door is not compromised.

With Flappie to the perfect cat flap

Flappie offers an innovative solution for cat owners who want a smart cat flap . With selective access control and prey detection using a camera and AI technology, cats are prevented from bringing prey into the house. The accompanying app allows you to control the cat flap from anywhere , receive notifications and monitor your cat. The advantages of Flappie are clear:

  • You get control and security for your home.
  • Your cat enjoys more freedom without the risk of bringing unwanted "gifts".
  • Easy to use thanks to the Flappie app, which provides you with videos of your cat and the ability to adjust settings. If you are interested in a clean and prey-free environment in your home, visit https://flappie.ch and discover how Flappie can make your life easier too.

Frequently Asked Questions

How much does it cost to install a cat flap in a window?

The cost of installing a cat flap in a window can vary depending on the type of cat flap and whether professional installation is required. Manual flaps are often cheaper, while microchip or magnetic flaps can cost more. Additional costs may apply for professional installation if you do not want or are unable to install yourself. It is important to choose a flap that suits both your needs and your budget.

Can you install a cat flap in glass?

Yes, you can install a cat flap in glass. With standard glass, a professional can make the cut-out on site. However, with safety glass, it is not possible to make a cut-out afterwards and a new glass with a pre-made cut-out is required. The thickness of the glass also plays a role and can affect the type of cat flap required.

Which tradesmen install cat flaps?

When installing a cat flap, you should contact an experienced tradesman to ensure that the integrity of the window or door is not compromised. Special fabrications may be necessary to ensure a perfect fit and secure installation. It is advisable to use a professional who has experience in installing cat flaps.

Can you install a cat flap in a balcony door?

Yes, you can fit a cat flap in a balcony door. Similar to windows, there are guidelines for balcony doors, although the size and opening mechanism of the door may require additional consideration. Special fitting is often necessary and it is advisable to contact an experienced tradesman to ensure a safe installation.