https://opensourcebridge.scien....ce/wiki/Fitting_Cat_
Installing a cat-flap on your door is a simple procedure. However, you'll need to know a few things before getting started. It is possible to install upvc panels with a cat door without having to cut holes in your wall or door. Many glass suppliers provide them with holes that is already designed for the purpose of a pet-door. 1. Safety Cat flaps made of upvc are simple to put in and can be fitted to many different types of doors. They are energy-efficient and weatherproof and come with a draft excluder built in