Front door
Your front door is your first line of defence against unlawful entry. Burglars will often target a home based on the levels of security that they can see being used on the front door. As well as fitting locks to secure your door, ensure that you have a door viewer and door chain fitted so that you can check who is at the door before allowing them entry.
A door is the most obvious way into the house, and must therefore be very secure. As well as the hardware listed overleaf, all doorsets should meet BS 3621: 2007 standard; at the very least they should be 44mm thick. they should be securely fixed to the structure of the building. If the door is outward opening then provision must be made to prevent an attack on the hinges. Consider replacing glazing with laminated glass which is harder to break through.
Choosing your lock
It’s no good buying a lock if it’s the wrong size for the door – follow these simple rules and you shouldn’t go far wrong.

Nightlatches
Generally speaking, all nightlatches are designed to ‘narrow’ or ‘standard’ widths. If the keyhole
is 40mm from the edge of the door, you need a narrow width lock. If the keyhole is 60mm from the edge, you need a standard width model. If your door has a glazed panel, look for a nightlatch that can be locked with a key from inside. This means that if someone smashes the glass, they cannot unlock the door by reaching in, as the nightlatch will be locked. A deadlocking door bolt will also prevent the bolt being forced using a credit card or similar.

Mortice Locks
Mortice locks come in two sizes, measured by the depth of the slot – or the ‘mortice’ – cut in the door edge to hold back the lock. Measure the distance from the door edge to the centre of the keyhole. If the distance is 44mm from the door edge, you need a 67mm mortice lock. If the distance is 57mm, you need a 80mm mortice lock.
A sashlock is a mortice lock with both a latch and a bolt, for use with handles. A deadlock is a mortice lock with just a bolt, usually used in conjunction with a nightlatch on front doors.
Mortice locks are operated either by levers or by a cylinder. The higher the number of levers within the mortice lock, the better security it provides. All external doors should be secured by a British Standard 5 Lever mortice lock. A cylinder operated mortice lock should use a kitemarked cylinder. All British Standard mortice locks contain components designed to prevent saw and drill attack.
Click here for more information on security standards
Are you buying a new PVCu door?
Whether you are buying a new front door, back door, or double glazed windows, it is important that you think about the security that your new doors and windows will provide.
A guide to buying PVCu doors and windows