The Extension Works
UK only: we design and build extensions in London & the South East of England (Surrey, Hampshire & Berkshire) — we can’t quote for projects outside the UK.
Back to all articles
bifold door safety features

Bifold Door Security for UK Extensions: PAS 24 Alone Won’t Secure It

For UK extensions, learn how PAS 24 certification, matching test reports, and certified installation protect bifold doors, and what proof to request.

The Extension Works 8 October 2026
Bifold Door Security for UK Extensions: PAS 24 Alone Won’t Secure It

Bifold Door Security for UK Extensions: PAS 24 Alone Won’t Secure It

Closed bifold doors in a UK rear extension

Choose a PAS 24 certified doorset and insist on certified installation. That single decision matters more than any add-on lock, because Approved Document Q ties the regulatory requirement for new dwellings directly to products tested and proven against forced entry. Aluminium bifold doors can meet strong security standards, but only when you can see the test report and the fitter’s evidence to prove it.

TL;DR:

  • Approved Document Q applies to accessible openings in new dwellings, and the certificate must cover the exact leaf, glazing, and frame configuration.
  • Check the report’s standard version, tested leaf sizes, glazing limits, and classification; a certificate for hardware alone does not validate the complete doorset.
  • Documented installation must follow the manufacturer’s fixing type and spacing, threshold details, and certified configuration; site alterations can erase the tested resistance.
  • Auxiliary locks, anti lift pins, and laminated glass can improve older doors, but they cannot create PAS 24 equivalence; replace weak frames.
  • Curtain sensors and acoustic glass break detectors provide early warning, while cameras only add visibility; detection should supplement, not replace, physical resistance.
The Extension Works
Plan a More Secure Rear Extension
The Extension Works combines design, planning and construction for single-storey rear extensions, with live 3D modelling to visualise your space.

Table of Contents

UK standards and regulations: Approved Document Q and PAS 24 explained

Before you compare suppliers, it helps to understand the two documents that actually govern bifold door security in England. Approved Document Q sets out Building Regulations guidance for security in dwellings, requiring doorsets and windows that could allow unauthorised access to be sufficiently robust and fitted with appropriate hardware. It applies to new dwellings, and specifically to easily accessible openings such as ground-floor bifold or patio doors, which are exactly the sort of opening a rear extension introduces.

The standard that Approved Document Q points to is PAS 24:2022+A1:2024, currently the recognised UK benchmark for enhanced security performance in doorsets and windows. It sets out test methods, classification, marking and acceptance criteria aimed at resisting opportunistic burglars rather than determined, tool-equipped intruders. A product carrying this certification has been tested as a complete doorset, not just assessed on paper, and the certificate should name the exact configuration tested: leaf type, glazing specification and frame construction. A generic product name on a brochure is not the same as a matching certificate.

Other standards appear in the market too. LPS 1175 and STS 202 are recognised certifications used where a higher risk profile applies, such as commercial premises or properties with specific insurance requirements, and police and self-build guidance note that any easily accessible doorset should be certificated to an appropriate standard for its risk level, PAS 24 included.

A doorset tested to PAS 24 is assessed as a complete unit, covering the frame, lock, glazing and fixings together, which is why a certificate for one component cannot stand in for a certificate on the finished product, according to BSI’s product description.

When you get a quote for bifold doors, ask the supplier for:

  • The PAS 24 certificate naming the specific door configuration, not a generic range.
  • An extract from the test report showing the leaf type and glazing tested.
  • Written confirmation of installer accreditation or fit-and-fix evidence.
  • Confirmation that the fixings and frame match the certified specification.

Building control sign-off for an extension typically checks these documents, and our guide to building regulations for extensions covers the wider compliance picture alongside door security specifically.

Feature checklist: the components that resist forced entry

A certificate confirms the doorset passed a test, but knowing which features drive that result helps you judge quality when comparing products or specifying upgrades.

  1. Multi-point locking systems: lock points engage at several positions along the leaf height rather than a single latch, spreading the load an intruder would need to overcome.
  2. Shootbolts: these drive bolts into the head and sill of the frame when the handle is operated, locking the top and bottom of each folding leaf rather than relying on the middle lock alone.
  3. Anti-lift devices: anti-jump pins and anti-lift screws fitted to the track and rollers stop a leaf being lifted clear of its running gear, a common attack method on sliding and folding systems.
  4. Hinge security: security-rated hinge bolts and concealed hinge designs prevent a leaf being forced off its hinges even when the lock itself holds.
  5. Glazing: laminated glass resists penetration far better than toughened glass alone, because the interlayer holds shards together under impact rather than shattering outward.
  6. Glazing bead security: internally fitted, tamper-resistant beads stop glass being levered out from outside once a pane is cracked.
  7. Frame reinforcement and striker plates: reinforced strike points and box-section frames resist the frame itself splitting or flexing under a hard-body attack.
  8. Factory-applied versus aftermarket hardware: hardware fitted and tested at the factory as part of the certificated doorset carries proven performance; hardware added later by a homeowner or general tradesperson does not.

Pro Tip: Ask whether the locking hardware was part of the original PAS 24 test or has been substituted since, because swapping a factory-tested lock for a cheaper aftermarket one can quietly void the doorset’s certified performance.

Testing methods: what PAS 24 testing involves and how to read a test report

PAS 24 testing combines two broad attack types. Hard-body attacks use tools such as crowbars, screwdrivers and wedges applied at known weak points, while soft-body attacks simulate a person’s shoulder or body weight impacting the door. Both are run against fixed time criteria, meaning a doorset must resist entry for a defined period before the test is considered a pass, as set out in BSI’s PAS 24 product assessment.

Crucially, the test assesses the doorset as a whole: frame, lock, glazing and fixings together, not any single part in isolation. That is why a certificate for “PAS 24 hardware” fitted to an uncertified frame tells you very little.

When reading a test report or certificate, check for:

  • The classification awarded and the test standard version referenced.
  • The scope: which leaf configurations and sizes the certificate actually covers.
  • Any stated limitations, such as maximum leaf width or a specific glazing type.
  • The testing body and date, since standards are periodically revised.

A factory test result also only describes the product as tested in controlled conditions. On-site performance depends on correct installation, and a certified doorset fitted incorrectly does not retain its tested resistance, a point Approved Document Q makes explicit when it comes to on-site alteration.

Installation matters: how correct fitting protects the doorset’s security

A PAS 24 certificate describes the product, not the finished installation, and Approved Document Q is clear that a certificated doorset can lose its tested performance if an installer alters it on site or fails to follow the manufacturer’s fixing specification.

Installer fixing a bifold frame to masonry

Fixings matter more than most homeowners expect. Frames need the anchor type and spacing specified by the manufacturer, usually set at defined centres around the perimeter, and substituting fewer or weaker fixings to save time undermines the entire test result. Threshold and reveal detail follows similar rules: recessing a frame beyond the manufacturer’s recommended limit, often done to achieve a flush external finish, can remove the support the frame relied on during testing. Readers comparing low threshold options for patio-style openings can see how this trade-off plays out in our guide to level threshold patio doors.

Checks worth making before and after fitting:

  • Confirm the installer holds relevant accreditation and ask for documented evidence of the completed installation.
  • Check fixings match the type and spacing stated in the manufacturer’s instructions, not a generic builder’s standard.
  • Check the threshold and reveal detail matches the certified configuration rather than a bespoke site adjustment.
  • Confirm no letterplate, cut-down or additional hole has been added to the leaf after certification.

Pro Tip: Photograph the fixings and frame detail before plaster or cladding covers them, so you have evidence the installation matched the certified specification if you ever need to query it.

Practical upgrades and retrofits for existing bifold doors

Existing bifold doors can often be improved without full replacement, though it is worth being realistic about what retrofitting achieves. Auxiliary locks, anti-lift pins, additional hinge bolts and separate top and bottom locks all add resistance, and guidance on securing large glass doors recommends this layered hardware approach alongside detection measures rather than relying on any single fix.

  • Auxiliary locks and hinge bolts add resistance points beyond the original lock.
  • Laminated glass replacement or tested security film improves resistance to impact, though film has lower proven performance than laminated glass fitted at manufacture.
  • Curtain sensors and acoustic glass-break detectors provide early warning before an intruder completes entry.
  • Cameras add visibility and a deterrent, though they do not physically slow an attack.

Layering hardware with detection is more effective than hardware alone, because the lock slows the attempt while the sensor alerts you before entry succeeds.

Retrofitting rarely achieves genuine PAS 24 equivalence, because the standard tests the frame, glazing and lock together as one certified unit, and a frame never tested to that standard cannot be brought up to it by adding hardware alone. Where an existing frame is old, thin-sectioned or already compromised, replacement with a certificated doorset is the safer route rather than layering fixes onto a weak base.

How security is handled on an integrated extension project

Specifying a certificated doorset at design stage, rather than retrofitting after the fact, removes most of the risk we have described. When glazing, frame and hardware are chosen before the opening is even built, there is no compromise between what the extension needs structurally and what the certificate requires. Co-ordinated trades and in-house project management, including live 3D modelling and a fixed price, reduce the installation errors (loose fixings, altered thresholds) that quietly undo a product’s tested performance.

— Esskay

An adjacent route: secure doorsets as part of a managed rear extension

We manage the specification and installation of bifold doors as part of every single-storey rear extension we build, so the certificate you were quoted is the doorset that actually gets fitted.

The Extension Works

Whatever route you take, ask any supplier to confirm the doorset is PAS 24 certified, the hardware is factory-fitted rather than substituted, and the installation is documented against the manufacturer’s fixing specification.

If your existing doors need cosmetic attention rather than full replacement, a specialist such as A Brush With Gus covers UPVC spraying and resurfacing, though a security upgrade should always sit alongside, not instead of, a certificated doorset.

FAQ

What is the typical cost of a bifold door in the UK?

Cost varies widely depending on size, configuration and glazing, and we do not publish a fixed price for doors in isolation since security hardware and certification affect the final figure. Within a managed rear extension, doorset specification is priced as part of the overall fixed quote rather than sold separately.

What is the typical height of a bifold door in the UK?

Standard bifold door heights are commonly specified to suit a project’s ceiling and threshold detail, and exact dimensions are confirmed during design rather than fixed industry-wide. A certificated doorset’s tested scope will state the specific leaf sizes it covers, so always check the height falls within that certified range.

Does a PAS 24 certificate guarantee my bifold door is secure once fitted?

No. The certificate describes the product as tested at the factory, but Approved Document Q notes that incorrect installation, such as altered fixings or added letterplates, can undo that tested performance. Always ask for documented evidence that the installation matched the manufacturer’s specification.

Can I make an existing bifold door as secure as a certificated one?

Retrofitting hardware such as anti-lift pins, auxiliary locks and laminated glass improves resistance but rarely matches full PAS 24 certification, since the standard tests frame, lock and glazing together as one unit. Where the existing frame is weak or old, replacing the doorset is generally the more reliable option.

Should I add an alarm as well as secure locks?

Yes, layering hardware with detection is widely recommended: locks and anti-lift devices slow an attempt, while curtain sensors and acoustic glass-break detectors give early warning before entry succeeds, as outlined in guidance on securing large glass doors.

Sources

For certification details, consult Approved Document Q and the current PAS 24 standard directly. Police and self-build guidance on doorset certification offers further practical context for homeowners planning new openings.