Window Security Locks and Best Practices for Home Safety

Why Window Security Matters

Around 30% of burglars enter properties through an open or unlocked window. Doors tend to receive the most attention when it comes to home security, but windows - particularly those on the ground floor or above flat-roof extensions - are equally important entry points.

Improving your window security does not have to be expensive. The right locks, combined with sensible habits, provide a significant deterrent.

Types of Window Security Locks

Keyed Window Locks

These require a key to engage or release, providing a higher level of security than standard window latches. They are compatible with most window styles, including casement, sash, and sliding windows. The key is best kept nearby but not visible from outside.

Window Bolts

Metal bolts that slide into a receiving plate, typically fitted to the interior side of the window frame. Simple and effective, they prevent windows from being opened even if the main latch is compromised.

Sash Jammers

A popular choice for sash and uPVC windows, sash jammers are small lever-operated devices that lock the window shut when engaged. They are particularly useful for ground-floor windows and any window accessible from a flat roof or extension.

Lockable Window Handles

These replace the standard handle on casement windows. The handle incorporates a small lock operated by a key, preventing the window from being opened without it. A good option for homes with young children, as they also reduce the risk of accidental falls.

Best Practices for Window Security

Having the right locks fitted is a good start, but how you use and maintain them matters just as much.

Lock windows whenever you leave a room - even for short periods, particularly on ground and first floors
Inspect locks regularly - check for wear, corrosion, or loose fixings and replace damaged hardware promptly
Consider security glazing - laminated or toughened glass is significantly harder to break than standard panes
Apply window security film - a transparent film that holds glass together if smashed, buying valuable time and deterring opportunists
Install visible locks - the sight of a lock on a window can be enough to make a burglar move on
Fit security grilles or bars on basement and ground-floor windows if your property is particularly exposed

Choosing the Right Locks for Your Windows

When selecting window locks, consider the following:

Window type - sash, casement, and sliding windows each suit different lock styles
Security rating - look for products that carry a Secured by Design or British Standard certification
Ease of emergency exit - locks should be quick to release from inside in case of a fire
Budget - most quality window locks are affordable; prioritise the most vulnerable windows first

If you are unsure which locks are appropriate for your property, a professional locksmith can assess your windows and recommend the most effective solutions.

Which Windows Are Most Vulnerable?

Not all windows carry equal risk. When prioritising your budget, focus on the windows most likely to be targeted:

Ground-floor windows at the rear - Rear access is preferred by burglars because it is less visible to neighbours and passers-by. These windows should always have locks fitted.
Windows above flat-roof extensions - A flat roof provides a convenient platform for reaching first-floor windows that many homeowners assume are safe. Treat these as ground-floor level.
Basement and lower-ground windows - Common in London Victorian terraces, these are often obscured by railings or planting, giving intruders cover while they work.
Windows near drainpipes or balconies - Anything that provides a climbing route to an upper window increases the risk to that opening.
Side-passage windows - Narrow passages between terraced houses are hidden from the street. Windows facing these passages need robust locks.

Prioritising these locations first gives you the best security return for your investment. A professional locksmith can walk the perimeter of your property with you and identify every vulnerable point in a matter of minutes.

Window Lock Installation: DIY or Professional?

Many window locks are designed for straightforward installation and come with full fitting instructions. If you are comfortable using a drill and a screwdriver, fitting keyed window locks, sash jammers, or lockable handles is a realistic DIY project.

However, professional installation is recommended when:

You have specialist window types such as heritage timber sashes or commercial-grade aluminium frames
The window frame is damaged, rotten, or weakened - fitting a lock to a compromised frame provides a false sense of security
You want locks fitted across multiple windows quickly and consistently
Your insurer requires locks to be fitted to a specific standard and you need documentation to prove compliance

Combining Window Security with Overall Home Security

Window locks work best as part of a broader home security approach. Consider pairing them with:

A good quality alarm system
External motion-activated lighting
CCTV covering the front and rear of the property
Upgraded door locks on all entry points
A door lock installation to bring your front and back doors up to the same standard as your windows

Our residential locksmith service covers the full range of home security improvements, from window locks to high-security door cylinders.