UPVC panels are a strong and long-lasting substitute for composite doors. They are strong energy efficient and are resistant to fire. They are also cost-effective and easy to maintain. The most straightforward way to install a cat flap into a uPVC panel is to purchase an extra double-glazed sealed unit https://www.repairmywindowsanddoors.co.uk/brighton-cat-flap-installer-near-me/