https://articlescad.com/using-....a-cat-flap-in-bifold
Adding a cat flap to your door's panel is an important task that should be completed by an experienced professional. These doors are typically constructed of a thin plastic exterior that is bonded to an insulation-enhancing, soft polystyrene base. It can be difficult to cut through these materials. It is a lot easier to put the cat flap into an existing glass pane, or to have the hole drilled in a new door. A Glazier can do this for you. Easy to Fit Upvc door panels are a great option if you have a cat that you would