PAS 24 Security Windows Guide | Window Fitters

PAS 24 Security Windows: The Complete Homeowner's Guide

When upgrading your home's windows and doors, security is often a top priority. In the UK glazing industry, the most important standard for forced-entry resistance is PAS 24. Understanding what PAS 24 is, how windows are tested, and how the standard relates to Building Regulations ensures your home is protected from opportunistic intruders.

Expert Reviewed by Marian Gheorghe, Head Window Fitter — Last reviewed: July 2026

What is PAS 24?

PAS 24 (Product Assessment Specification) is a British Standard that evaluates the security performance of complete windows and doorsets. Unlike standards that test individual components (like a lock or hinge in isolation), PAS 24 tests the entire assembled window or doorset — including the frame material, glass unit, hinges, locking mechanisms, handles, and fixing anchors.

To achieve PAS 24 certification, a window must withstand a series of physical attacks conducted by UKAS-accredited laboratory testers using tools commonly used by burglars (such as crowbars, chisels, screwdrivers, and physical impact devices).

The Law: Approved Document Q (Security)

In England and Wales, Approved Document Q (Security) of the Building Regulations states that all new dwellings (including new builds and conversions) must be fitted with secure windows and doors. The regulations define a secure window as one that meets the requirements of PAS 24 or an equivalent international security standard.

While Document Q does not strictly apply to like-for-like window replacements in existing private homes, most reputable window fitters supply PAS 24 certified systems as standard for all installations, ensuring homeowners receive the highest level of security protection.

How are PAS 24 Windows Tested?

To pass certification, a window must survive a rigorous testing regime designed to replicate a burglar trying to break in:

1. Manipulation Test: Testers attempt to bypass the locking system or slide back the latch bolts from the outside using thin metal probes and cards.
2. Manual Attack Test: Testers spend 3 minutes attempting to gain entry using chisels, screwdrivers, and levers to force open the opening sashes or break the locking points.
3. Mechanical Loading Test: Hydraulic rams apply parallel and perpendicular loads of up to 3.0kN (approx. 300kg) to every hinge and locking point to test frame rigidity.
4. Impact Test: A 50kg steel-faced pendulum ram strikes the window frame and glass at key points to verify structural integrity.

Key Components of a PAS 24 Window

A window that achieves PAS 24 certification includes several security features:

• Internal Glazing Beads: The plastic beads that hold the glass in place are positioned on the *inside* of the room. This prevents a burglar from simply prying off the beads from the outside and removing the glass pane.
• Multi-Point Locking Systems: Casement windows feature shootbolts that lock into the top and bottom of the frame, alongside mushroom cams that hook into steel keeps along the side.
• Reinforced Frames: uPVC frames are reinforced with internal steel ribs to prevent the frame from flexing under pressure.
• Security Hinges: Fitted with anti-jemmy claws that lock the hinge side of the sash to the frame, preventing the window from being pried open from the hinge side.

At Window Fitters Ltd, all our premium uPVC window systems (Profile 22, Deceuninck, Liniar, and Rehau) are manufactured and fitted to PAS 24 standards, ensuring robust security for your London home.

About the Author: Marian Gheorghe

Head Window Fitter & Active Director, Window Fitters Ltd

Marian Gheorghe is the Head Window Fitter and Director of Window Fitters Ltd. He has over 15 years of technical glazing experience in London, specializing in security hardware configurations, multi-point lock alignments, and Document Q compliance.

Connect on LinkedIn → Expert Reviewed: July 2026

PAS 24 FAQs

Is PAS 24 the same as Secured By Design?

No. PAS 24 is a technical British Standard test. Secured By Design (SBD) is a police-backed security initiative. SBD uses PAS 24 as its baseline requirement, but adds additional corporate audits and security guidelines.

Does PAS 24 require laminated glass?

Under Document Q, accessible windows (like ground floor windows or basement windows) must be fitted with at least one pane of laminated safety glass (tested to BS EN 356 Class P1A) to resist glass smashing attacks, which is an additional requirement alongside the PAS 24 frame certification.

Can old windows be upgraded to PAS 24?

While you can upgrade locks and handles on old frames, you cannot retroactively certify an old window to PAS 24 standards, as the certification applies to the complete frame and hardware system as manufactured.