How Can I Make a Vulnerable Window More Secure?

If a window feels like a weak point — a ground-floor opening, a quiet side return or a window down an alleyway — it is wise for you to create an extra secure window for these locations. The key is to think about the window as a system: the glass, the lock, and the often-forgotten hinge side all need to do their job. Get one wrong and the other two count for very little.

Start With the Glass — and Avoid the Toughened Trap

The single most common misconception we hear is that toughened glass is “security glass.” It isn’t. Toughened glass is four to five times stronger than ordinary glass, so it takes a much harder hit to break. But that strength is a trap. The moment it does break, it doesn’t crack — it shatters completely into small granular pieces and falls away, leaving a clean, wide-open hole. An intruder could be through in seconds, with no jagged edges to slow them down. In security terms a shattered pane of toughened glass can actually be easier to gain entry through than standard glass!

The genuinely secure option is glass that stays in place when struck. Old-fashioned wired glass does this, the embedded mesh holds the fragments — but it’s dated and few people want the look of it in a home. That leaves laminated glass as the best practical answer.

Why laminated glass wins. Laminated glass is two or more panes bonded around a tough plastic (PVB) interlayer — the same construction as a car windscreen. When it’s struck the panes may craze and crack, but the interlayer holds the whole sheet together, so no hole appears. To get through, an attacker has to keep striking the same spot, over and over, breaking through layer after layer. That takes time and makes a great deal of noise — the two things a burglar most wants to avoid. Most attempts are abandoned when they come across laminated glass. For graded protection, look for laminated glass tested to BS EN 356, the European standard for security glazing.

Glass at a Glance

Glass type	How it behaves when hit	Security verdict
Standard (annealed)	Breaks into large, jagged shards.	Moderate — easily broken, however the dangerous edges risks injury.
Toughened (tempered)	Much harder to crack, but when it goes it collapses entirely into small granular pieces.	Misleading — strong until it fails, then leaves a clear, open hole.
Wired	Embedded wire mesh holds fragments in place.	Effective but dated and unattractive.
Laminated	The glass pane may crack, but the PVB interlayer holds everything together — no hole opens up.	Best for security — forces a sustained, noisy attack that defeats most break-ins.

Then the Lock — Multi-Point, Key-Operated

Glass is only half the battle; the locking hardware is a further part to the solution. A single central latch leaves the top and bottom of the sash free to be levered. The standard to aim for is a multi-point locking mechanism, which throws several bolts/catches along the frame at once when the handle is in the locked position, clamping the sash tight in multiple places rather than just the middle.

Crucially, that handle should be key-lockable. A handle that lifts and locks with a key cannot simply be operated from inside if a thief breaks a small pane to reach through, and it can’t be jiggled or forced back down. Always engage the key — a multi-point lock left unlocked is doing only a fraction of its job.

The often Overlooked Weak Spot — the Hinge Side

Here’s the point most people miss, but burglars don’t! It’s natural to focus all your attention on the lock side of an opening sash and fit a good mechanism there. But that effort can be wasted, because a determined attacker won’t always go for the lock — they’ll go for the hinge side instead.

If the hinges are the only thing holding that edge, a crowbar or pry tool slipped into the gap can lever, or “jemmy,” the sash open from the hinge edge, springing it out of the frame entirely while your expensive lock stays perfectly intact on the other side. A window is only as strong as its weakest edge.

The fix: hinge bolts / hinge guards. These are bolts or interlocking pins fitted on the hinge side. When the window is closed they engage into a matching keep in the frame, so even if the hinges are attacked the sash is mechanically locked into the frame on that edge too. They’re inexpensive, discreet, and they close off exactly the route a crowbar attack relies on. Fit them as standard on any sash where security matters to a vulnerable window.

A Quick Security Checklist

• Specify laminated glass (ideally to BS EN 356) on vulnerable and ground-floor windows — not just toughened.
• Fit a multi-point locking mechanism rather than a single central latch.
• Use a key-lockable handle — and actually lock it.
• Protect the hinge side with hinge bolts or guards to defeat crowbar attacks..

How SevenDay Can Help

As supply-only specialists across 22 trade counter depots, SevenDay can supply laminated and security-rated sealed units, multi-point locking mechanisms, key-lockable handles and hinge protection to suit your frames. Bring your sizes and specification to your nearest depot and the team will help you put together the right combination of glass and hardware for the job.