https://postheaven.net/quiltsn....ail1/adding-a-cat-fl
A cat flap can create a draught if it's left open. This is a common problem encountered by cat owners. A draught excluder can help minimise cold air entering the home, however an animal flap that is insulated will offer greater protection against the elements. Tomsgates has a wide selection of insulated dog doors and cat flaps that work for all kinds of installations, including wall installations. The Material Insulation is among the most important characteristics of a cat-door. Insulation is what keeps cold air