Why the reputation exists
A traditional timber sash held shut with a single centre catch is not difficult to defeat, and anyone who has ever opened a painted-shut sash with a bit of leverage understands why. The vulnerability is structural: two panels that slide past each other, held together at one point.
That is the problem a modern sash has to solve, and it is solved with hardware and reinforcement rather than by changing what the window looks like.
What PAS 24: 2022 actually means
PAS 24 is a British standard for enhanced security performance in doors and windows. It is a test, not a description: a sample window is subjected to a defined sequence of manual attack, including attempts to lever, cut and force the frame and the locking, and it either resists for the required period or it does not.
ECOSlide® meets PAS 24: 2022 as standard rather than as an upgrade, which is the point worth taking away. The security specification is not something you have to remember to ask for.
Secured by Design, and when you need it
Secured by Design is the official police security initiative. A window that carries it has met a specification the police service backs, and it is what satisfies Approved Document Q where a property is required to meet it, which in England applies principally to new dwellings.
ECOSlide® is also available as a Secured by Design window. On a secluded property, a ground floor at the back of a house, or anywhere set behind planting and away from a road, it is worth specifying whether or not the building regulations require it.
None of the security specification is visible. The bar inside the sash, the cam locks, the jam blocks and the aluminium reinforcement are all internal, so from either side you see the same frame, the same glazing bars and the same colour.
What is actually inside the window
The specification is worth reading in plain terms rather than as a list of names.
- An anti-lever bar built into the sash, so the window cannot be prised open at the point a crowbar would naturally go.
- High security cam locks holding both sashes, with one fitted up to 799mm and two at 800mm and above, so a wider window gains locking points rather than stretching the same hardware further.
- Jam blocks at the top of the sash, which stop the sash being pushed out of its track.
- Aluminium sash reinforcements as standard in every window built to the Approved Document Q specification.
- Toughened glass in both sashes as standard, with laminated available where you want glass that holds together rather than breaking clear.
- Key operated travel restrictors limiting the opening to 100mm, removable with the key when you want the window fully open.
The two options parents ask about
The 100mm restrictor is the one that comes up most. It is worth specifying on any upstairs room a child uses, and because it is key operated it limits the opening without permanently sacrificing the window.
The other is the Fire Egress design option, which allows a window to open as an emergency escape route. Those two pull in opposite directions, so they are decided per window rather than across a house, and it is worth raising both at survey so the right one goes on the right room. A loft conversion or a reconfigured bedroom is the usual case where escape matters.
What to tell your insurer
Insurers generally want to know the standard rather than the brand. PAS 24: 2022 is the answer, with Secured by Design where it has been specified. The Declarations of Performance are downloadable from the homepage without a form, covering BS EN 14351 for the windows, BS EN 1279 for the sealed units and BS EN 12150 for the toughened glass, all dated 28 November 2025.
Questions we get asked
Is a sliding sash window less secure than a casement?
Not as specified here. PAS 24: 2022 is the standard for both, and the locking on a sash is designed around the way it moves: cam locks holding both sashes, an anti-lever bar built into the sash, jam blocks at the top and toughened glass as standard in both sashes.
Does a higher security specification change how the window looks?
No. The bar inside the sash, the cam locks, the jam blocks and the aluminium reinforcement are all internal to the window. The frame, the glazing bar layout and the colour are unchanged, which matters where an estate or a conservation officer governs appearance.
Can the windows be limited so a child cannot open them fully?
Yes. Key operated travel restrictors limit the opening to 100mm and are removable with the key. They are worth specifying on any upstairs room a child uses, and they are decided per window rather than across the whole house.
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Talk to us about your windows
Send a photograph of the front of the property and roughly how many windows are involved, or your schedule of sizes for a supply-only order, and we will tell you what is realistic before anyone comes out.
Call 0800 861 1450, message us on WhatsApp, or email info@sashwindowfactory.co.uk.