PAS24 Security Windows Explained

What Is PAS24?

PAS24 is the British security standard for windows and doors. It stands for Publicly Available Specification 24, published by BSI (British Standards Institution). The test subjects a window to a series of physical attacks — forced entry attempts using common burglary tools — and measures how well the window resists them. A window that passes PAS24 testing has demonstrated “enhanced security” performance.

When Is PAS24 Required?

Under Approved Document Q of the Building Regulations (England), all new dwellings and conversions creating new dwellings must have windows and doors that meet PAS24 or equivalent security performance. This applies to new builds, barn conversions, loft conversions creating a new dwelling, and commercial-to-residential conversions.

Replacement windows in existing dwellings do not currently require PAS24 compliance under Document Q, though many insurers and local authorities recommend it. Some planning conditions and Secured by Design schemes also require PAS24.

What Does the Test Involve?

PAS24 testing includes mechanical loading (pushing and pulling the sash or casement under force), manipulation attacks (attempting to release locks and keeps with tools inserted through gaps), and an impact test (dropping a 50kg steel-faced impactor onto the glazing from height). The window must resist all attacks for a defined period without allowing access to the interior.

How Timber Windows Achieve PAS24

There is a common misconception that timber windows cannot achieve PAS24 and that only uPVC or aluminium is strong enough. This is not true. Timber — particularly engineered redwood and Accoya — has excellent resistance to forced entry because wood absorbs impact energy rather than shattering or deforming. PAS24 compliance in timber windows is achieved through a combination of multi-point locking systems (espagnolette locks engaging at multiple points around the frame), laminated glass (which holds together under impact rather than shattering), reinforced keeps and striker plates, and shoot-bolt locking at top and bottom of the sash.

PAS24 and Sash Windows

Traditional sash windows with simple fitch fasteners do not meet PAS24 on their own. To achieve compliance, sash windows require upgraded locking — typically a combination of fitch fasteners with key-locking, sash restrictors, and in some cases Brighton fasteners at the meeting rail. The glazing must also be laminated on at least one face. Our sash windows can be specified to PAS24 requirements where needed, with the locking hardware concealed within the traditional profiles.

Need PAS24-compliant timber windows? Use our 3D configurator to specify your requirements, or contact us to discuss your project with our technical team.