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You and your cat will both benefit from incorporating an animal flap into your bifold door. It also helps to stop extreme heat or cold weather from entering your home. The first step is to measure your pet's size to determine the size of the door flap you'll require. This will help you design an opening for the flap that is the right size. Outdoor Access Even those with no DIY skills can manage to install a cat flap on an external back door. This will help you avoid the cost and headache of hiring a carpenter or handyman to do th