How to Select Door Locks for Every UK Door

A door handle may be the first detail a visitor notices, but the lock behind it determines how that door performs every day. A beautifully finished lever set cannot compensate for the wrong lockcase, an oversized cylinder or a lock that conflicts with a fire-rated door assembly. Knowing how to select door locks means treating security, access, compliance and appearance as one coordinated decision.

For a single domestic door, that may be a straightforward choice. Across a house, flat scheme, hospitality project or workplace, it becomes an ironmongery exercise: every opening needs a function, a compatible set of components and a finish that belongs to the wider interior.

Start with the door function, not the finish

The first question is simple: what must this door allow people to do? A front entrance needs controlled access and resistance to attack. A bathroom needs privacy with emergency release. A bedroom may need only a latch, or a light-duty privacy lock. A plant room, store or office may require key-controlled access, while a fire door must close and latch reliably as part of a tested doorset.

Avoid specifying one lock type across every room for the sake of visual consistency. Consistency should come from coordinated handles, escutcheons, turns and finishes, not from forcing the same internal mechanism onto doors with different duties.

For project work, establish each opening type before choosing products. Record whether the door is internal or external, timber, aluminium or steel, its thickness, whether it is fire-rated, its handing and swing, the required level of security, and who needs access. This is the foundation of an effective ironmongery schedule.

Choose the lock type that suits the opening

Mortice sashlocks and deadlocks

A mortice sashlock combines a spring latch with a deadbolt in one lockcase. It is commonly used where a lever handle operates the latch and a key locks the door, such as a traditional timber entrance or office door. The latch gives everyday convenience; the deadbolt provides security when locked.

A mortice deadlock has no latch. It is generally paired with a separate latch or used where the door is secured without a lever-operated latch. On a residential entrance, the choice between a sashlock and a separate nightlatch and deadlock arrangement depends on the door design, desired operation and security requirements.

For externally facing timber doors, look beyond the label of “high security”. A lock should be selected as part of the complete assembly, including the cylinder or key mechanism, security furniture, strike plate, fixings and door construction. Where insurance or project requirements apply, check the precise standard requested. BS 3621 is often relevant for key-operated rim and mortice locks, while other standards may suit doors requiring keyless egress from inside.

Euro cylinder locks and multipoint systems

Many modern entrance doors, particularly composite, uPVC and aluminium doors, use a multipoint locking mechanism operated by a handle and secured by a euro profile cylinder. The central cylinder is only one part of the system, but it deserves close attention. Its security rating, resistance to snapping or drilling, key control and correct projection beyond the door furniture all affect performance.

Measure cylinder size from the centre of the fixing screw to each side, allowing for the door thickness, backplate or escutcheon and any security hardware. A cylinder that projects excessively can create a security weakness and looks poorly resolved. One that is too short may sit recessed and be difficult to operate.

Where a specific security level is required, a TS 007-rated cylinder and compatible security escutcheon may be appropriate. Confirm the requirement against the door manufacturer’s guidance, the building’s security strategy and any Secured by Design or insurer specification. Ratings are useful, but only when the surrounding hardware is equally suitable.

Bathroom, privacy and indicator locks

Bathroom doors do not need a keyed entrance lock, but they do need a clear and dependable privacy function. A bathroom lockcase used with a thumbturn and emergency-release indicator offers an elegant solution for homes, hotels and workplaces. The external release allows access in an emergency, while an occupancy indicator is particularly useful in shared or public-facing settings.

Check the lockcase’s follower size, centres and spindle arrangement against the handle and turn furniture. A common source of avoidable installation problems is combining hardware with mismatched dimensions. Privacy sets should also be judged by feel: a stiff turn or poorly aligned release diminishes an otherwise refined interior.

Latches for non-locking internal doors

Not every door needs a lock. Passage doors between living spaces, circulation areas and low-risk rooms often require only a latch. Tubular latches are compact and suit many internal doors, while mortice latches may be chosen where a heavier handle or a more substantial architectural specification is needed.

The latch must be rated and sized for the door and handle. Deep, weighty lever handles can place more demand on the mechanism than a lightweight domestic handle, particularly on frequently used doors. A quality latch helps the handle return cleanly and prevents the sagging, rattling operation that quickly makes new joinery feel tired.

Check door construction and critical dimensions

A lock is never selected in isolation. Confirm the door thickness first, then the available depth within the stile. The lockcase must fit without weakening narrow timber sections or clashing with glazing, panels, rails or concealed hardware.

Backset is the distance from the door edge to the centre of the keyhole or follower. It affects the position of the handle and how comfortable it feels in use. Case depth must also be considered, especially on narrow-stile doors. Centres - usually the distance between the handle spindle and keyhole or cylinder - must match the chosen furniture.

Door handing matters for certain locks, strike plates and latches. Some products are reversible; others must be ordered for the correct handing. Do not leave this to site assumption. Establish whether the door is viewed from the hinge side or opening face according to the manufacturer’s convention, and record it consistently throughout the schedule.

The frame and strike are equally important. A strong lock fitted to a poorly prepared keep will not perform as intended. Ensure the strike plate, box and fixings are suitable for the frame material and the anticipated use of the opening.

Fire doors require a tested approach

On a fire door, compatibility is not a finishing detail. The lock, latch, handles, hinges, closer, intumescent protection and door construction need to work together within the door’s tested evidence or certification scope. A fire door must positively latch when it closes, so a latchbolt or suitable locking latch is normally essential.

Do not assume that any metal lockcase is acceptable because it appears substantial. Check its fire rating, the permitted door types and thicknesses, whether intumescent protection is required, and whether the selected lever furniture is approved for the intended application. Hardware may also need to meet accessibility and escape requirements, particularly in communal, education, healthcare and commercial buildings.

If electronic access control, hold-open devices or escape hardware are involved, coordinate the lock selection early. Retrofitting these decisions late can disrupt door certification, cabling routes and the clean lines of the finished door.

Balance security with the way people use the building

The highest available security specification is not automatically the best choice. A private study may need a discreet key lock, while a short-let property may benefit from managed access. A communal entrance requires controlled entry and reliable egress. In an office, keys can become an operational burden, making a master-keyed system, digital lock or access-control solution more appropriate.

Think about keying before placing an order. Decide which doors should be keyed alike, which need individual keys, and whether a master key hierarchy is required. For larger developments, this should be documented carefully to prevent duplicate access routes or last-minute changes that complicate installation.

Electronic locking can reduce key management, but it introduces power, programming, audit and override considerations. It is most effective when specified as part of the access strategy, rather than added as a decorative smart-home upgrade.

Coordinate the visible hardware

Locks create the functional foundation; handles, escutcheons and turns create the visible language of the door. Choose furniture that suits the lock type and door style. A euro cylinder requires a euro-profile escutcheon or backplate. A mortice key lock needs a matching keyhole profile. Bathroom locks need a turn and release that align with the handle geometry.

Finish coordination deserves the same discipline. Satin stainless steel, polished nickel, antique brass, bronze and matt black each react differently to light, touch and wear. On a whole-house or multi-unit scheme, the most successful results come from repeating a considered palette across lever handles, cabinet hardware, window fittings, hinges and accessories, while allowing for the practical demands of each location.

This is where an ironmongery schedule earns its value. It connects every opening with its lock function, handle set, hinges, closer, cylinder, signage and finish. ITFITZ can support this coordination from early design decisions through to a specification that can be ordered and installed with confidence.

Before committing, review a sample or working set where possible. Check the handle action, the cylinder projection, the look of the escutcheon against the door finish and the operation from both sides. The right door lock should disappear into daily use while making every opening feel intentional, secure and properly resolved.