Rafal Kaczynski
Hi Katy Fitting cat flaps to glass doors or windows can be tricky and you should get a qualified glazier to do the job. If you have single glazed glass doors the glazier should be able to cut a circular hole for a cat flap. However all doors in modern buildings have to be fitted with safety glass. It is possible to fit cat flaps in double-glazed doors and safety glass but the holes need to be cut when the glass is being made. Replacing all the glass in your door may be expensive, so see if it is possible to replace just the lower door panel with a piece of glass with a hole for the cat flap. Alternatively, since windows do not have to have safety glass, think about fitting a flap in a kitchen window, if your cat can easily obtain access to it. I hope this will help Best regards Rafal
