https://telegra.ph/Fit-a-Cat-F....lap-in-a-UPVC-Door-P
https://squareblogs.net/peenat....om7/upvc-door-panels
uPVC door panels are an alternative for composite doors. They are strong energy efficient, durable, and fireproof. Additionally, they are affordable and easy to maintain. Ordering a double-glazed sealed unit that has an opening already cut for the cat flap is the easiest method of installing an animal flap inside a uPVC sheet. This is safer than cutting a hole in an existing glass panel. UPVC Doors are easy to maintain Unlike traditional wooden doors, uP