Door & Window Security in the UK

1. Why door & window security matters more than people think

Front doors are the visible face of a home’s security and most homeowners over-invest in them while neglecting the back. The thief, who makes a living from this, is far more interested in the side gate, the rear French door, the kitchen window, the small toilet pane and the rear casement nobody overlooked. These are the openings that yield in seconds with the tools that fit inside a coat pocket.

Door cylinders are the single most-attacked component on a UK home — a non-anti-snap Euro cylinder on a uPVC back door can be defeated in under fifteen seconds. Windows fall to a smaller repertoire of attacks, but with comparable speed where the hardware is wrong. The good news is that the fixes are well-understood, the standards are stable, and the cost differential between an insecure opening and a fully PAS 24 / TS 007 3-star opening is now small.

A modern aluminium casement with multipoint locking and a key-operated handle — the entry-level specification for any ground-floor opening in 2026.

The good news is that the cost differential between an insecure window and a fully PAS 24 window is now small — on a typical UK retrofit, in the order of £40–£90 per opening. The case for upgrading is therefore overwhelmingly economic, before any consideration of safety or peace of mind.

2. Window locks and locking handles

Every operable window in a modern UK home should have a locking handle. There are two flavours:

Key-operated handle.

A small barrel cylinder is integrated into the handle escutcheon. Turning the key locks the handle in the closed position so it cannot be rotated even if the glass is broken and an intruder reaches in. Insurers expect this on every ground-floor and accessible first-floor window.

Push-button handle.

A button releases a sprung pin that allows the handle to rotate; the button can only be released from inside. Cheaper, but offers slightly less resistance to manipulation through a broken pane.

The handle drives an espagnolette or shootbolt mechanism inside the sash — the actual locking is done not at the handle but at the frame, where steel cams or bolts engage into reinforced keeps. This is the engagement that matters; the handle is just the user interface.

Sash jammers and additional locks

Older uPVC windows that pre-date multipoint locking can be retrofitted with sash jammers — small, surface-mounted locks that bolt the sash to the frame independently of the main handle. Two per casement is the conventional minimum. Sash jammers are a sensible upgrade for any window that cannot economically be replaced; they are not a substitute for a properly-specified new window.

3. Hinges and security hinges (doors & windows)

Hinges are easy to overlook because they sit out of sight when the door or sash is closed. They are also one of the most-attacked components in a forced entry. The principles below apply to both windows and doors; we’ll call out where they differ.

Window hinge types

Friction stay (4-bar)

The standard for modern UK casements — a stainless-steel scissor mechanism that holds the sash in any opening position without a separate stay. Choose grade 304 stainless for inland use, 316 marine-grade for coastal exposure.

Egress (easy-clean)

A friction stay variant that allows the sash to slide laterally as it opens, giving access to the outer face of the glass for cleaning. Used on first floor and above.

Butt hinge

Traditional door-style hinge sometimes used on heritage casements. Must include a hinge-pin retention and an anti-lift bolt; otherwise vulnerable to pin removal from outside.

Concealed hinge

Hidden inside the rebate when the sash is closed — common on modern aluminium and on flush casements. Inherently tamper-resistant because the hinge body is inaccessible.

Door hinge types

Butt hinge (3 per leaf)

The conventional door hinge — three flag-shaped hinges per leaf, screwed to leaf and frame. Always pair with hinge-side dog-bolts so the leaf cannot be lifted off if the pins are removed from outside.

Pivot / parliament hinge

Used on heavy timber and aluminium doors where the leaf needs to swing through 180°. Lower attack surface than a butt hinge but specify with the same dog-bolt protection.

Concealed door hinge

Standard on modern aluminium doors and on flush front doors. The hinge body is inside the rebate, accessible only when the door is open. Inherently tamper-resistant.

Hinge-side dog-bolts

Not strictly a hinge but the partner to one. A steel peg in the leaf engages into a hole in the frame, parallel to the hinge axis. With dog-bolts in place, even a hinge with the pins removed cannot release the leaf. Three per door is the standard specification.

What makes a hinge a security hinge

A security hinge has three properties: it cannot be detached from outside (anti-lift bolt or dog-bolt that engages into the frame), it cannot be drilled out (hardened steel pin), and it cannot corrode and fail in service (stainless steel or marine-grade stainless). All three matter on doors and windows alike; the second and third are the ones routinely omitted on the cheapest quotations.

What makes a hinge a security hinge

A common attack on cheap butt-hinged casements and on older external doors is to punch out the hinge pins with a long nail set, then lift the leaf off its hinges entirely. A hinge with no anti-lift bolt offers zero resistance.

Specify hinges with an integrated hinge-side anti-lift bolt (windows) or hinge-side dog-bolt (doors) — a small steel peg that engages into a hole in the frame parallel to the hinge axis. Even with the pins removed, the leaf cannot be lifted clear.

4. Multipoint locks on uPVC and aluminium (doors & windows)

A multipoint lock is the locking mechanism that runs along the inner edge of the sash or door leaf and engages into the frame at multiple points when the handle is rotated. It is the single most important piece of mechanical hardware on either a door or a window from a security point of view, and it is a near-universal feature on modern aluminium and uPVC openings — though the engagement count, the bolt geometry and the gearbox throw differ between doors and windows.

On a typical aluminium casement of 600 × 1,200mm, the multipoint mechanism will drive three to four mushroom-headed cams or shootbolts into reinforced steel keeps in the frame. On a tall tilt-and-turn of 700 × 2,200mm, the engagement count rises to eight or more, with shootbolts at the top and bottom corners. The forces involved are considerable: a properly-engaged multipoint lock distributes prying loads across the entire perimeter of the sash, so the attacker has to overcome multiple steel-into-steel engagements simultaneously rather than a single point of failure.

Cam shapes and keeps

Mushroom cams — cylindrical with an enlarged head, drawn under a steel keep when the handle is rotated. Resists levering because the keep grips the head from above. Shootbolts — round or square steel bolts that protrude from the sash into receivers in the frame. Used at corners and on tall sashes for maximum prying resistance. Hooks — rotating steel hooks that swing over a strike plate. Common on uPVC, less common on aluminium. Slightly more vulnerable to top-of-sash levering than mushroom cams.

On aluminium systems specified by Glazed Window Systems Ltd, the standard locking pattern is mushroom cams along the long edges with shootbolts at top and bottom corners on any sash over 1,200mm tall. Keeps are pressed steel mortised into the aluminium profile, not surface-screwed into a uPVC reinforcement — an important difference, because there is no plastic for the keep to be torn out of.

Doors use the same logic at greater scale. A modern uPVC or aluminium external doorset runs a multipoint gearbox the full height of the leaf, with hooks or deadbolts at top and bottom and a centre latch — typically three to five engagement points on a standard door, more on a tall doorset or a French-door pair. The gearbox is driven by the Euro profile cylinder we cover next, so the cylinder is the ‘key’ (literally) to whether the multipoint mechanism can be released without breaking down the door.

5. Euro profile cylinders & TS 007

Across the UK, almost every uPVC and aluminium door — and a smaller proportion of tilt-and-turn and parallel-opening windows — uses a Euro profile cylinder. It is the small, rectangular-flanged barrel into which the key is inserted; it sits on the inside edge of the door, retained by a single fixing screw that runs through the door at its centre. The cylinder drives the multipoint locking gearbox in the door leaf. Without the right cylinder, no other piece of door hardware really matters: the cylinder is where attacks concentrate, and where the highest-value security upgrade can be made.

uPVC and aluminium doors will accept the same cylinders — the body is interchangeable — but the length changes, because uPVC profiles are thicker and aluminium profiles are slimmer. The user must order a cylinder matched to the door it is being fitted to.

The TS 007 Kitemark and SS312 Diamond — the ‘star’ ratings

UK door cylinders are graded against two recognised standards: TS 007 (the British Kitemark) and Sold Secure SS312 Diamond (the Master Locksmiths Association rating). Either is accepted by UK home insurers; the TS 007 system is the one most homeowners encounter on packaging.

For new build, retrofit or any front or rear door, a TS 007 3-star or SS312 Diamond cylinder is the minimum sensible specification. The cost differential over an unrated cylinder is in the order of £20–£40 per door, and it is the single highest-value security upgrade available to any UK homeowner.

6. Anti-snap, anti-bump, anti-pick, anti-drill

The marketing terms on cylinder packaging are not interchangeable. Each refers to a specific defence against a specific attack technique.

Anti-snap

The most critical feature. The cylinder body has sacrificial break-lines milled into it. Under a snap attack the protruding section breaks off cleanly, leaving the deeper locking mechanism intact and the door still secured. Without this feature, a non-rated cylinder snaps in under 15 seconds.

Anti-bump

Defeats ‘lock bumping’ — a technique where a specially-cut key is struck with a soft mallet to jump the pins to the shear line. Anti-bump cylinders use modified pin geometry, sprung counter-pins or magnetic elements that resist the bump impulse.

Anti-pick

Uses pins with unusual profiles — mushroom heads, spool waists, serrated edges — that produce false ‘sets’ on the shear line. The picker feels what seems to be the correct stack height but the cylinder will not turn. A determined attacker may eventually pick a 3-star cylinder, but not in any time-frame compatible with quiet entry.

Anti-drill

Hardened steel pins or ceramic plates set into the cylinder body. They deflect or shatter standard drill bits, requiring carbide-tipped bits and considerable noise to defeat — well outside what a typical opportunist intruder is prepared to commit.

The 3mm rule — how much cylinder should protrude?

This is the single most-overlooked specification on UK doors. A cylinder that sticks out beyond the handle escutcheon offers a thief enough ‘meat’ to grip with mole grips or a snap tool, and even a TS 007 3-star anti-snap cylinder can be defeated if it is the wrong length.

The cylinder should finish flush with the handle, with no more than 3mm of protrusion on the outside face. If your existing cylinder protrudes 5mm or more, replace it with a correctly-measured cylinder before doing anything else — this single change is more valuable than any other retrofit.

To measure: from the centre of the cylinder fixing screw hole, measure to the outside face of the door (e.g. 35mm) and to the inside face of the door (e.g. 45mm). Quote it as ‘35/45’. The first number is always the external length.

7. Cylinder formats & uPVC vs aluminium

Beyond the rating and the length, three physical formats matter for UK doors. Each has its proper place; choosing the wrong one creates either a security gap or a fire-safety risk.

Double cylinder

Key both sides. The standard format for most front and rear doors. Locked with a key on either face. Full security — but a key must be kept near the door for fire-escape egress, otherwise occupants can be trapped inside in a fire.

Anti-bump

Key outside, knob inside. Used on flat entrance doors where keyless egress is essential, and where building regulations or housing-association policy demand it. Avoid where there is glass within arm’s reach of the thumbturn — a broken pane lets the intruder simply rotate the knob.

Half (single) cylinder

Key one side only; flat metal disc the other. Suits garage side doors, patio sliders and outbuildings where the door is only ever locked or unlocked from the outside. Cannot be used on a habitable doorway because there is no way out without the key.

uPVC versus aluminium — what changes

The cylinder body is interchangeable between uPVC and aluminium doors, but two practical things differ:

‍
Cylinder length.
uPVC doors have thicker sections — a typical front door uses 35/45, 35/55 or 45/45. Aluminium doors are slimmer; you may need 30/30 or 35/35. Always measure the existing cylinder before ordering.

Cylinder shape.
Some commercial-grade aluminium doors and some patio systems use

‍oval cylinders
rather than Euro cylinders. The oval cylinder is round-ended top and bottom rather than rectangular-flanged. Check the shape of the existing cylinder before buying a replacement — an oval barrel will not fit a Euro cutout and vice versa.

Multipoint gearbox.
uPVC doors usually run a hook-and-deadbolt multipoint, sometimes with shootbolts. Aluminium doors of the type Glazed Window Systems Ltd supply use heavier-gauge gearboxes with deeper bolt throw — both formats are driven by the Euro cylinder, but the aluminium gearbox is better-supported by the surrounding profile and resists frame deflection more effectively under attack.

Motorised locks & biometric integration (doors & windows)

That single property is why every UK home insurer assumes keyed locks on accessible windows, and why every PAS 24-tested window includes them as standard. It is also why the small frustration of carrying a window key — usually kept in a key-cabinet by the door — is wholly worth it.

10. What is PAS 24?

PAS 24 is the UK’s enhanced-security testing standard for windows and external doorsets. The current version is PAS 24:2022, published by BSI on behalf of the construction industry and referenced by Approved Document Q of the Building Regulations for England and by the police-led Secured by Design scheme.

A window is not ‘PAS 24 by design’. It must be physically tested in an accredited laboratory, with the exact glazing, locking and hinge configuration that will be supplied to the customer. The test sequence subjects the assembled window to:

Manipulation tests — the tester is given a defined kit of common tools (chisels, screwdrivers, levers, hammers up to a defined weight) and a defined time to attempt entry without breaking the glass.

Soft-body impact — a 30kg sand-filled impactor is swung against the window from prescribed positions, simulating a body weight applied to weakest points.

Hard-body impact — smaller, denser impactors simulating the corners of common tools.

Mechanical loading — static and cyclic loads applied to the locking and hinge points.

Cylinder attacks — for windows that use euro cylinders, snap, pick, drill and bump tests.

The window passes only if no test routine permits entry within the prescribed time. The test certificate carries the certificate number, the testing laboratory, the manufacturer and a precise specification of the tested unit; it is this number that should be supplied to the insurer.

Related standards worth knowing

BS 7950 — the predecessor to PAS 24 for windows; some older specifications still cite it.

BS EN 1627 — European resistance-class standard (RC1 to RC6). PAS 24 is broadly equivalent to RC2.

TS 007 — cylinder security standard; 1-star, 2-star and 3-star ratings denote escalating resistance to snap, drill, pick and bump.

Secured by Design — the police preferred-product scheme; an SBD-licensed window must hold a current PAS 24 certificate.

11. UK insurance implications

UK home insurance policies almost universally require ‘key-operated locks’ on accessible windows as a condition of cover, where ‘accessible’ is defined as any opening reachable without a ladder — ground floor, plus any first-floor opening adjacent to a flat roof, porch, garage roof, bay roof or boundary wall.

The clause that catches people out

Most policies state that if a claim arises and the insurer establishes that the window in question did not have a working key-operated lock, the claim may be reduced or refused. This is not theoretical — it is a routine reason for partial settlements after burglary claims.

If you have any doubt about whether your existing windows comply, photograph each handle, send the images to your broker and ask for written confirmation that they meet the policy condition.

Discounts and security ratings

A PAS 24-certified window with multipoint locking and key-operated handles typically qualifies the property for the insurer’s ‘security-rated’ tier, which translates to a 5–15% reduction on the contents premium and, sometimes, on the buildings premium. The discount is small in absolute terms but compounds over the life of the policy and is the easy answer to whether the £40–£90 per-opening upgrade is worth it.

Where the certificate matters

For a new build or major retrofit, ask the installer for the certificate of conformity at handover. Keep a digital copy with the property documents, alongside the FENSA or CERTASS certificate. In the event of a claim, those two documents settle the question of compliance in seconds.

12. How thieves actually break into UK doors and windows

The repertoire is small and well-documented. Almost every successful UK break-in — door or window — falls into one of these techniques. Knowing which attack each piece of hardware defeats is the simplest way to specify properly.

Window attacks

Attack

How it works

What defeats it

1. Reach-through

Break a small adjacent pane, reach in, rotate the handle from inside.

Key-operated locking handle. Without the key the multipoint lock cannot be released.

2. Lever attack on the lock keep

Insert a flat-bladed screwdriver between sash and frame at the lock keep, lever outward until the cam disengages or the keep tears out of the uPVC reinforcement.

Multipoint locking with mushroom cams and pressed-steel keeps mortised into the profile, not surface-screwed.

3. Glazing bead removal

On older externally-beaded uPVC, a thin chisel pops the glazing bead off, the sealed unit is pushed inward, the intruder steps through.

Internally-beaded glazing (the bead is on the inside, inaccessible from outside). All modern PAS 24 windows are internally beaded by design.

4. Hinge-pin removal

On butt-hinged casements, punch out the hinge pins, lift the sash off its hinges.

Friction-stay or four-bar hinges, or butt hinges with hinge-side anti-lift bolts.

Door attacks

Attack

How it works

What defeats it

5. Cylinder snap

The most common UK door attack. Grip the protruding portion of the Euro cylinder with mole grips or a snap tool, lever sharply, the cylinder breaks across the centre fixing-screw line, the locking cam is exposed, the multipoint lock retracts. Defeats a non-anti-snap cylinder in 10–15 seconds.

TS 007 3-star or SS312 Diamond anti-snap cylinder, sized so it protrudes no more than 3mm beyond the handle. Optionally a 2-star security handle that hides the cylinder body entirely.

6. Cylinder drilling

Standard high-speed drill bit through the cylinder pin stack, breaking out the pins so the plug can be turned with a screwdriver.

Anti-drill cylinder — hardened steel pins or ceramic plates set into the body. Defeats standard bits and significantly slows carbide-tipped attempts.

7. Lock bumping

A specially-cut ‘bump key’ is inserted and struck with a soft mallet; the impulse jumps the pins to the shear line and the cylinder turns.

Anti-bump cylinder — modified pin geometry, sprung counter-pins or magnetic elements that prevent the bump from setting the pins.

8. Lock picking

Tension applied to the cylinder while individual pins are manipulated to the shear line.

Anti-pick cylinder — mushroom, spool or serrated pins that produce false sets and frustrate the picker.

9. Door spreading / kicking

Body weight applied to the lock area; on a uPVC door with a worn or undersized multipoint, the leaf can flex enough to disengage the hooks from the keep.

Aluminium doorset (no flex) and / or a hinged side with three security hinges plus a hinge-side dog-bolt. Reinforced steel keeps mortised into the frame.

10. Hinge attack

On a door with exposed butt hinges, punch out the hinge pins and lever the leaf out of the frame on the lock side.

Concealed hinges or hinge-side dog-bolts that engage into the frame independently of the hinge pins.

13. How to specify a secure door or window

For windows

For any new window in a UK home — on the ground floor and on accessible first-floor openings — the minimum specification is: PAS 24:2022 certified system, certificate number on file. Multipoint locking with at least three engagement points per casement and four per tall sash. Key-operated locking handle (preferred) or push-button locking handle. Stainless-steel friction-stay hinges with hinge-side anti-lift bolt, grade 316 in coastal areas. Internal beading. Toughened or laminated glass to BS 6206 / EN 12150 in any pane within 800mm of floor or 300mm of a door. Where a Euro cylinder is fitted (some tilt-and-turn and parallel-opening systems do), TS 007 3-star or SS312 Diamond. Hinge-side restrictor to 100mm with key release, where children are present.

For doors

For any new external door in a UK home — front, rear, side or French — the minimum specification is: PAS 24:2022 certified doorset, certificate number on file.

Multipoint locking gearbox with at least three engagement points (typical configuration: deadbolt, central latch and at least two hooks or shootbolts).

TS 007 3-star or SS312 Diamond Euro cylinder, sized so the external face protrudes no more than 3mm beyond the handle, with anti-snap, anti-bump, anti-pick and anti-drill features.

Cylinder format chosen to suit the door — double cylinder for most front and rear doors; thumbturn cylinder where keyless egress is required, and only where there is no glass within arm’s reach of the thumbturn; half cylinder for one-way doors only.

Stainless-steel hinges with at least one hinge-side dog-bolt that engages into the frame independent of the hinge pin.

Reinforced steel keeps mortised into the frame, not screwed into uPVC reinforcement. Laminated or toughened glass to BS 6206 in any glazed panel within 800mm of floor; consider P1A laminated for any glass within arm’s reach of an internal thumbturn or door handle.

Aluminium doorsets where security and longevity are the primary criteria; uPVC where budget is the dominant constraint and the configuration permits a properly-reinforced multipoint and a 3mm-flush 3-star cylinder.

For the prestige tier, add motorised multipoint locking on selected doors and windows, biometric integration via a single controller that authenticates by fingerprint, time-bound access for cleaners and dog walkers, and tilt sensors that report the open/closed state to the home-automation controller. See the smart-home guide for the full specification.

14. Frequently asked

Do I need PAS 24 on first-floor windows?

Approved Document Q (England) requires PAS 24 only on ‘accessible’ windows and doors of new dwellings, where accessibility is judged on whether the opening is reachable without a ladder. In practice this means ground floor, plus any first-floor opening adjacent to a flat roof, porch, garage roof, bay or boundary wall. Many specifiers extend PAS 24 to every operable window on the front and rear elevations regardless — the cost differential is modest and the consistency across the elevation is worth it.

Are tilt-and-turn windows more or less secure than casements?

Equivalently secure when both are PAS 24 and both have keyed locking handles. Tilt-and-turn typically has more engagement points (eight or more) and is therefore harder to lever, but if the cylinder is exposed and not TS 007-rated it can be attacked at the cylinder. A TS 007 3-star cylinder eliminates that vector.

What about secondary glazing for security?

Secondary glazing is primarily a thermal and acoustic upgrade, but a well-specified secondary unit with a separate keyed lock adds a meaningful second barrier. It is most useful on listed properties where the primary glazing cannot be replaced.

Can I retrofit security to existing uPVC windows?

To a degree. Retrofit options include sash jammers, replacement keyed handles to upgrade non-locking handles, replacement cylinders to TS 007 3-star, and security film bonded to the inner face of the glass. These reduce risk but cannot turn an externally-beaded mid-1990s uPVC unit into a PAS 24 window. For ground-floor accessible openings on a property valued at any reasonable level, replacement is the rational choice.

Does insurance care which window is which?

Yes — the policy condition typically applies to every accessible opening, individually. One non-locking window in a bathroom is enough to put a claim at risk if that window was the entry point. Audit the whole house, not just the obvious openings. How long should secure window hardware last?

A modern aluminium PAS 24 window with stainless-steel friction stays, hardened-steel multipoint mechanism and TS 007 cylinder is engineered for a 25–40 year service life with no hardware replacement, subject to occasional lubrication of the mechanism and the friction stays. uPVC equivalents have a shorter hardware life because the reinforcement and the gasketing degrade earlier; expect 18–25 years before serious refurbishment.

Can I just upgrade the cylinder on my existing uPVC door?

Yes — and on most pre-2015 UK uPVC doors it is the single highest-value security upgrade you can make. Measure your existing cylinder (centre of fixing screw to outside face, then to inside face), buy a TS 007 3-star or SS312 Diamond cylinder of the correct length, and replace it. Tools required: a Phillips screwdriver and ten minutes. Most cylinders are around £40–£90 and the change typically takes a uPVC door from ‘15-second snap’ to ‘not worth attempting’.

Should the cylinder ever stick out beyond the handle?

No. The cylinder should finish flush with the handle escutcheon, with no more than 3mm of protrusion on the external face. Anything more provides grip for a snap attack and can defeat even an anti-snap cylinder. If yours protrudes 5mm or more, replace it with the correctly-measured length before adding any other security.

Are TS 007 and SS312 Diamond essentially the same?

Both are accepted as full-protection cylinder standards by UK home insurers. SS312 Diamond is a more demanding snap test in some respects and is favoured by professional locksmiths; TS 007 3-star is the BSI Kitemark and is the rating most homeowners encounter on packaging. Either is sufficient for any UK home; specify whichever your supplier carries in the correct size.

What about smart locks that replace the cylinder entirely?

Modern biometric and motorised smart locks integrate into the same Euro cylinder cutout, so the door leaf does not need to be modified. The smart lock unit incorporates a TS 007 3-star or SS312 Diamond physical cylinder behind the electronic reader, so the underlying mechanical security is preserved. See the smart-home guide and the biometric section on the prestige page for what we fit.