A modern sliding door is secured by a multipoint lock with hook bolts that grip the frame, anti-lift blocks that stop the sliding panel being lifted off its track, a tight central interlock and safety glass held in by beads on the inside. Older sliders gained a poor reputation because many had a single latch and glazing beads on the outside; current systems are designed very differently, and many are available tested to PAS 24, the UK enhanced security test standard for doorsets.
This guide explains each security feature, what PAS 24 and Secured by Design actually mean, which questions to ask before you buy, and what to check with your home insurer before you sign off a specification.
How is a sliding door locked?
The handle on the sliding panel operates a multipoint lock: one turn of the key or lever throws several locking points at once along the edge of the panel. On sliding doors these are usually hook bolts, which swing out and hook into keeps on the frame or the fixed panel. A hook is much harder to force than a straight bolt, because pulling or levering the panel tightens the hook against its keep rather than sliding it free.
Most systems use two to four hooks on a standard-height door, with more on taller panels. The cylinder that operates the lock matters just as much as the hooks. Ask for an anti-snap, anti-bump cylinder, and check that it sits flush with the handle, because a cylinder that stands proud is easier to grip and attack. A key-lockable handle on the inside means a broken pane does not give someone easy access to open the door.
What stops a sliding panel being lifted out?
A sliding panel runs on rollers in a track, so the classic weakness of old doors was that the panel could be lifted up and out from outside. Current systems fit anti-lift blocks in the head of the frame. They fill the gap above the panel so it cannot rise far enough to clear the bottom track. They are small, inexpensive parts, but they are essential, and they must be checked and refitted correctly after any roller adjustment.
The interlock is where the sliding panel overlaps the fixed panel or another sliding panel. On a well-made door the two profiles engage along their full height when closed, so there is no gap for a bar. Slimline systems keep the interlock narrow, around 20–25 mm, but rely on the same overlapping principle, and some are reinforced inside the profile.
Does the glass make a difference to security?
Glass is often the part an intruder tests first. All glazing in doors must be safety glass under the Building Regulations, which means toughened or laminated glass. Toughened glass is strong but, if it does break, it shatters into small pieces and leaves a clear hole. Laminated glass has a plastic interlayer bonded between two sheets, so even when it cracks it stays in one piece and resists someone climbing through. For security, ask for laminated glass on at least one pane of ground-floor doors that are out of sight from the street.
How the glass is held in is just as important. Internal glazing beads clip in from inside the house, so the sealed unit cannot be removed from outside. Some systems also bond the glass to the frame with security tape or adhesive. If a door has beads on the outside, ask what stops the glass being taken out. There is more on glass types in our sliding door glass guide.
What is PAS 24?
PAS 24 is the UK enhanced security test standard for doorsets. A doorset tested to PAS 24 has been put through a series of physical attacks in a test lab: tools are used on the lock and cylinder, the glazing is attacked, the panel is levered and the hardware is put under load. The test covers the whole doorset as tested, meaning the frame, panels, glass, locks and hardware working together.
That last point matters. A frame does not become PAS 24 just because a good lock is fitted, and a door can lose that standing if parts are swapped for cheaper ones. Ask for the test evidence to name the system and configuration you are buying. Many systems are available tested to PAS 24, but not every size, panel layout or glass build is covered, so check that your specification matches.
Where a system offers an enhanced locking package as an option, it is shown as a separate line in your written quote so you can see exactly what it adds.
What does Secured by Design mean?
Secured by Design is a police-backed initiative that sets security standards for homes and the products used in them. Its door requirements build on PAS 24. Manufacturers can apply for specific products to be recognised, and developers of new housing often design to its guidance.
Recognition belongs to a particular product, not to a door type or an installer. We do not claim Secured by Design membership. If recognition matters to you, for example because a developer or a planning condition asks for it, check the exact product on the Secured by Design website and ask for the doorset to be specified to match.
Do the Building Regulations require a secure sliding door?
In England, Approved Document Q sets security requirements for doors and windows in new dwellings, including doors that are easy to reach from the ground. A doorset tested to PAS 24 is one recognised way of meeting it. Approved Document Q does not apply when you replace a door in an existing home, so on a replacement the level of security is your choice.
Replacement doors in England are still controlled fittings, so the energy and safety glazing rules apply, and the work must be done by an installer registered with a competent person scheme or notified to Building Control. Our building regulations guide covers this in more detail.
Will a sliding door affect my home insurance?
Insurers set their own conditions, so check your policy wording rather than assuming. Some policies ask for doors to have locks of a stated standard, for keys to be removed and kept out of sight, or for doors to be locked whenever the house is empty. A claim can be reduced or refused if those conditions were not met.
Before you order, read the security section of your policy, then ask your insurer or broker whether a multipoint lock with hook bolts satisfies it, or whether they want a particular standard such as PAS 24. Keep the paperwork from your installation, including the product details and any test evidence, in case the insurer asks for it later.
What should I ask for when I buy?
- A multipoint lock with hook bolts, and how many hooks your panel height gets
- An anti-snap, anti-bump cylinder that sits flush with the handle
- Anti-lift blocks fitted in the head of the frame
- Internal glazing beads, or a bonded glazing system
- Laminated glass on at least one pane where the door is out of sight
- A key-lockable handle on the inside
- Test evidence that covers your exact size and layout, if you want PAS 24
Our secure sliding doors page sets out the security options we offer, and every feature you choose is listed in your written quote. Surveys are free for new doors and replacements, and you can start a quote online.
Common questions
Are sliding doors less secure than French doors?
Not by design. A modern sliding door with a multipoint lock, hook bolts, anti-lift blocks, internal glazing beads and laminated glass can be as secure as a hinged door. The weak sliders people remember had single latches and external beads. What matters is the specification of the door you buy, so ask what locking, glazing and anti-lift features are included rather than judging by door type.
Can I upgrade the locks on my existing sliding door?
Often, yes. Many sliders can take a new multipoint lock or gearbox, an anti-snap cylinder and fresh anti-lift blocks, provided parts are still available for the system. Older doors with external beads or a single-point lock may not be worth upgrading. We quote lock repairs from photos or a diagnostic visit, with any call-out charge agreed before we attend.
Is every sliding door you supply tested to PAS 24?
No, and be wary of anyone who says that every door they sell is. Systems are available tested to PAS 24, but the test applies to a specific doorset configuration. If you want PAS 24, tell us at the start and we will specify a system and layout covered by the test evidence, with any enhanced locking upgrade shown as a separate line in your quote.
Do I need laminated glass in a sliding door?
You need safety glass in any door, which can be toughened or laminated. Laminated glass is not required for security on a replacement door, but it is the stronger choice where intrusion is a concern because it holds together when broken. A sensible specification for a door facing a private garden is laminated glass on the inner pane with toughened glass on the outer pane.