https://botdb.win/wiki/Adding_....a_Composite_Door_Cat
If you're looking for an option to let your pet in and out without having to worry about them leaving unwelcome "gifts" in the house look into an upvc door panel that has a cat flaps. This is less expensive than replacing the entire door and easier to put in. Although it is possible to fit a cat flap in your own uPVC door, you need to understand that this is a difficult job that could lead to costly errors. Easy to install It's important that you can let your cat or dog into and out of the house. This will help you keep them safe