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It is best to hire an expert to install a cat-flap inside your home. DIY jobs usually result in a poorly-fitted pet flap, which can let in draughts and lead to more energy costs. SheffLOCK can fit the cat flap into all types of doors including wood, uPVC, composite and glass doors, as well as external walls. It takes about two hours to install the cat flap. Pet flaps cost money A pet flap lets your cat to come and go whenever it wishes. However, if the flap isn't properly fitted, it could let heat escape from your ho