Patio doors and windows are often targeted by thieves, because in the past they have been easy to open. Burglars will lift the whole window off its rails (often using that garden spade you conveniently left in your unlocked shed) and gain entry this way.

Patio windows which are made of aluminium are often the weakest type. Modern UPVC should come with multi-point locking systems as standard.

Get specialist advice on fitting locks to patio doors.

Patio doors should have special locks fitted top and bottom unless they already have a multi-locking system

If you're thinking of buying UPVC or metal framed windows or doors, make sure that they come with good built-in locks and a fitted chain, which can be very difficult and expensive to add afterwards. Check they are constructed to BS (British Standard) 7950, if they are to be considered as security windows.