Main external doors
If you have a wooden door, use any five lever mortice lock or better. Look for British Standard 3621 locks for wooden doors.
If you have plastic and PVC doors, use a multi-point locking system for PVC doors and windows, including PVC patio doors.
If your patio door doesn’t have a multi-point locking system, we advise a key operated lock to be fitted to the central rail (the vertical rail where the doors overlap).