Keeping your home safe and secure is of utmost importance to everyone, and unlocked doors are a burglar's favourite entry and exit point, so it's important to make sure that yours are fitted with good-quality locks and security devices. This applies especially to your front door, since you normally have to lock it from the outside whenever you leave the house.

Mortice locks

These are the most secure type of lock you can fit to any door. As the name implies, they fit in a slot called a mortice formed in the edge of the door, and shoot a hardened steel bolt into a keeper recessed in the doorframe when the key is turned. Make sure that any lock you buy is marked made to British Standard BS3621 and carries the British Standard kitemark. Versions with three, five and seven levers are available; pick one with at least five for maximum security.

Mortice sashlocks

A side or back door often remains unlocked during the day to allow access to the back garden from the house. The best security lock for these doors is a mortice sashlock, which combines a mortice lock and a handle-operated latch mechanism so the door can be opened and shut without the need to operate the key. The door can then be securely locked at night or whenever you leave the house.

Unlike mortice locks, sash locks are handed left or right to suit the way the door opens, or may have a reversible latch bolt to enable the lock to fit either edge of the door.

Cylinder locks

The locking mechanism of a cylinder lock is contained in a brass barrel that fits in a hole drilled through the door. On the inside there is a surface-mounted lock body fitted with a knob or lever so the door can be opened from inside without having to use a key. On these so-called night latches there is also a knob that you can operate to prevent the latch being forced, but these are not very secure.

The best cylinder locks have a deadlocking facility that locks the latch securely with a key, used from inside at night and from outside when you leave the house. Again, make sure you buy a lock made to BS3621. For maximum door security, fit both a deadlocking cylinder lock and a mortice lock.

Profile cylinder mortice locks combine the security of a mortice lock with the convenience of a cylinder lock with its small, easily portable key. The lock body fits in a mortice in the door edge, while the cylinder fits in a hole drilled through the door.

Patio door locks

Sliding patio doors are relatively easy to force unless they have been designed with integral multi-point locking and anti-lift devices. Many older doors do not have these features, so it's wise to add a pair of key-operated surface-mounted locks to each sliding door, installed either at each side of the door or at the top and bottom. The lock body is screwed to the door frame or sill, and the bolt engages in a hole drilled in the door itself.

Door security accessories

You can improve the security of any door by fitting surface-mounted bolts or concealed mortice rack bolts, which fit in a hole drilled in the door edge and are operated by a special key.

Hinge bolts -are fixed steel pegs that fit in to holes drilled in the hinge edge of the door and engage in holes drilled in the door frame as the door closes. They prevent the hinged edge of the door from being forced.

Door viewers -are small lenses fitted in a hole drilled through a solid front door that allow you to see who the caller is before you open the door.

Door chains and bars - restrict the door opening to a few inches, helping to prevent a caller from forcing entry as you open the door.