A door does much more than separate one room from another. It helps keep your home secure, provides privacy, and contributes to the overall functionality of your property. Selecting the correct locking mechanism is therefore just as important as choosing the right door furniture.
With so many different lock types available, it can be difficult to know which one is best suited to your application. This guide explains the most common door locks, how they work, and where they're typically installed. Before replacing any external lock, it's also worth checking your home insurance policy to ensure your chosen lock meets the required security standards.
Contents
Understanding the Parts of a Lock
Before exploring the different types of locks, it's useful to understand some of the components you'll come across. While not every lock contains all of these parts, many share the same basic features.
Deadbolt
The solid metal bolt that extends into the door frame when the key is turned, securing the door in place.
Strike Plate (Receiver Plate)
A metal plate fixed to the door frame which receives the latch or deadbolt when the door closes.
Faceplate
Attached to the edge of the door, the faceplate protects the lock mechanism while providing a neat, finished appearance.
Euro Cylinder and Keyway
The euro cylinder houses the locking mechanism and accepts the key. Inside the cylinder, a series of pins align when the correct key is inserted, allowing the lock to operate.
Spindle
A square metal bar that passes through the lock case and connects both handles or knobs, allowing them to operate the latch.
Latch Bolt
A spring-loaded bolt that keeps a door closed without locking it. It retracts when the handle or knob is turned.
Deadlocks
Deadlocks are one of the most secure locking options available for timber doors. Installed within the body of the door, they are operated solely by a key, making them an excellent choice where security is a priority.
Unlike locks fitted with an internal thumbturn, a traditional mortice deadlock cannot simply be released from inside without the key. This reduces the risk of someone reaching through a broken window to unlock the door from within.
Deadlocks are commonly paired with a separate tubular latch and a pair of mortice door knobs. The latch keeps the door closed during everyday use, while the deadlock is only engaged when additional security is required.
For a refined finish, the keyhole is usually complemented by a decorative escutcheon, protecting the timber around the lock while matching the rest of the door furniture.
Above: From The Anvil's Aged Brass BS 5 Lever Deadlock 2.5"
Sash Locks
Mortice sash locks combine a locking mechanism and a sprung latch within a single lock case, making them ideal for doors fitted with lever handles.
The latch is operated by the handles, allowing the door to open and close freely without using the key. When security is required, simply turn the key to engage the deadbolt.
Sash locks are most commonly available as either 3-lever or 5-lever models.
A 3-lever sash lock offers a basic level of security and is generally recommended for internal doors. A 5-lever lock provides significantly greater protection, making it the preferred choice for external entrances. The additional levers make the lock more resistant to picking and unauthorised key duplication.
Most lever handles are designed with a keyhole positioned beneath the handle, often finished with a matching escutcheon for a more polished appearance.
Above: From The Anvil's Black 5 Lever BS Sash Lock 2.5"
Bathroom Locks
Bathroom locks are specifically designed to provide privacy rather than high levels of security.
From inside the room, the lock is engaged using a thumbturn, while the external side features an emergency release that can usually be operated with a coin if access is required.
Like a sash lock, a bathroom lock includes a latch that allows the handle or door knob to open and close the door during normal use. The privacy bolt is only activated when needed.
Although most commonly installed on bathroom doors, these locks are equally suitable for bedrooms, dressing rooms, or other internal spaces where privacy is important.
Above: From The Anvil's Satin Chrome Heavy Duty Bathroom Mortice Lock 2.5"
Multipoint Locks
Multipoint locking systems are the standard choice for uPVC, composite, aluminium and many modern external doors.
Rather than relying on a single locking point, these systems secure the door at multiple positions along its height. A long internal mechanism runs the length of the door, engaging locking points at the top, centre and bottom.
The system is operated using espagnolette lever handles. Lifting the handle activates the locking points, while turning the key secures them in place.
Because the door is locked in several locations simultaneously, multipoint systems provide increased resistance against forced entry while also helping create a tighter weather seal.
Above: From The Anvil's Stainless Steel Backset Hook 3 Point Door Lock
Night Latches
Night latches remain a popular choice for many traditional front doors, particularly on older period properties.
These locks automatically engage when the door closes, meaning the entrance locks itself without requiring the key. From outside, the lock is opened using a key, while inside it is released with a simple thumbturn.
Many night latches also include a snib function. When activated, the snib prevents the lock from being opened with a key from outside, offering additional security overnight.
Night latches are frequently used alongside centre door knobs or cylinder pulls. Since these pieces of hardware don't operate a latch themselves, they simply provide a comfortable grip for opening and closing the door while the night latch controls the locking mechanism.
Above: From The Anvil's Traditional Case Night Latch
Tubular Latches
Not every internal door requires a lock. For rooms where privacy is sufficient without additional security, a tubular latch provides a simple and effective solution.
A tubular latch contains only a spring-loaded latch bolt, allowing the handle or door knob to keep the door securely closed while remaining easy to open.
These latches are concealed within the edge of the door for a clean finish and are compatible with a wide variety of door furniture, including lever handles, lever-on-rose sets and traditional door knobs.
For pairs of internal doors, the strike plate may be installed into the adjoining door rather than the frame, allowing both doors to close neatly together.
Above: From The Anvil's Satin Brass Tubular Mortice Latch
Choosing the Right Lock
The best lock depends on the type of door and the level of security required.
- Deadlocks are ideal where maximum security is the priority.
- Sash locks combine everyday convenience with secure locking for external doors.
- Bathroom locks provide privacy without requiring a key.
- Multipoint locks are the preferred solution for modern external doors.
- Night latches offer automatic locking for traditional front entrances.
- Tubular latches are perfect for internal doors that don't need to lock.
Understanding how each lock functions makes it much easier to choose the right hardware for your project.
If you're still unsure which lock is most suitable for your home, our team is always happy to offer expert advice and help you find the ideal solution.