security-tips

Double Glazing Security Tips - Home Security

In many cases, it is not possible to retro-fit any extra locks to UPVC windows to improve your home security.

This is because the material used is not strong enough to support a metal lock fitted with steel screws. It could also damage the window and perhaps invalidate any existing warranty. Double glazed window locking systems should be fitted at the time of manufacture. A general rule to follow is that the handle should not be the only means of keeping the window closed. The locking system should be fitted within the framework and the handle is used as a means of throwing or engaging the internal locking system.

Always consult the manufacturer/supplier before attempting to fit any extra locks. There are locks that can be fitted to UPVC casement windows, but only if there is no integral locking system within the framework, typically where the only means of security is a locking handle.

There are two main types of double glazed locking systems:


The first is espagnolette (multi-point) locking, which are bolts (normally 3 sets) set into the window and located into locking points in the frame when the handle is turned. The bolts should be mushroom headed so that they can engage behind the locking point, thus enabling the window to resist being forced apart from the frame.


The second type is deadlock shoot bolts which locate into the frame at both opening side corners. There is also a deadlock which secures the opening side of the window at the handle. The window can also be fitted with high-security friction hinges which locate into the frame on the hinge side.
For additional strength sections of hardened aluminum or galvanized steel reinforcements should be fitted at the time of manufacture within the hollow profiles of the windows and frames, so that the locking systems can be secured through the UPVC frames into the reinforcements.

It is preferable for the windows to be fitted with internal beading to avoid the possibility of the glass being removed from the outside. There are some systems which have external beading but are secure because the glass is adhered to the frame or secured by special tamper-proof clips, but in most cases internal beading is preferable.

Lastly, if you are considering replacing your existing windows, look for the new British Standard 7950 kitemark. It has been established to set specific manufacturing standards of design and security for windows.

Secondary glazing


Though they are not installed these days, there are still many houses fitted with secondary glazing, mainly aluminum. Because of the narrow profile and intrinsic weakness of the frames, there is very little additional security which can be added. Such glazing has generally been fitted to wooden framed windows, which can be secured by standard window locks.

However, sliding secondary glazing can offer additional security with the fitting of a key operated clamp on the bottom rail of the frame. Particularly in hot conditions, windows are left open to allow the circulation of air. This, inevitably, reduces the level of security. By fitting a sliding window lock to the bottom rail you can restrict the slide to a few inches.

Alternatively, drilling a small hole through the bottom rail at the point at which you wish to restrict the slider and inserting an appropriately sized bolt will suffice. Additionally, to prevent the slider being lifted, fit a wooden block of a suitable depth into the track above the slider. When used in conjunction with stay locks or child safety locks on the primary glazed window, security is enhanced further.

To discuss how we can help to make your home, or business more secure, call us today.

Back to blog

BM Security are experts in Residential and Commercial security solutions to protect your home, your family and your business.Our specialist engineers can advise on, install and maintain the right security products to keep you and those around you safe. Whether you need an emergency locksmith, a burglar alarm or CCTV system, access control keyless entry, or home automation and smart technology, our experience ensure you receive the best service.

Contact Us