Many criminals gain entry through the patio door, so it makes sense to re-enforce the security in this area of the home. This can easily be done with the use of a multi-locking system. A multi-locking system allows a door to be locked at multiple points into the door frame, making it a much stronger seal than that of a standard lock.
However, not all patio doors can be fitted with a locking system like this. If this is the case, it’s recommended that extra locks are fitted. These are fitted on the bottom fixed frame pushing through to the sliding frame in the centre and on the side frame at the opening point no lower than a third of the way from the top of the door. Most such locks are push to lock and key to open and are therefore easy to use. Make sure there is enough frame to fit them on if drilling is required. If in doubt, consult the installer or manufacturer.