Security Issues:
Windows - Locking systems

If you are approaching towards high age, and when you will look back to the days when the back door you kepted open, and the key to front door was kept under the mat outside, or hanging on a piece of string under through the letterbox. Well, all those, long days are unfortunately gone now, and home security is not high on the list of criteris for people contemplating replacement windows.

The basic double glazing locks are cockspur, which cannot be opened from outside once it has been closed. Some cockspur handles lock with a kay of sorts which is a bit silly on fanlights because a person would have to be indoors to get to the handle to open it. The reason making cockspur handles were locking is because of larger final usually side opening windows below a fanlight, and these could be more secure against being opened from outside if locked for when a top fanlight vent was left ajar.

Espagnolette ('espags' in the trade) locks were a single, surface mounted rod with two or more mushroom headed roller cams that were popular through the mid eighties to mid nineties, but being seen on new windows less and less, and the latest generation of multi-point 'shoot-bolt' higher security locking systems with a 'lock-ajar' facility are more or less now the norm. Hinges also play their part in the overall security of a window and with the addition of security hinges on an opening vent it means a total of five lock points.

Yes, this is a window lock, not a door lock!
Here is a picture of the 'Saracen' lock that I use as standard on all of my PVC-U windows.

When closed the handle locks automatically, and the action used for undoing the handle is to press a button and the handle can be key locked as well if required.

In the locked position, which is either fully closed or slightly ajar, the shoot bolt extends into a glass fibre reinforced nylon 'keep' at both the top and the bottom of a side opener, and on each side of a top opener.

Notice that in addition to the shoot bolts there is a central mortise security point. Do not confuse this with a lock that has a roller cam at this point, as that would be not so much for security, but rather to draw the opener in on the weather proofing.

The old saying "if an intruder wants to get in he will" is very true, for example he can always just smash the glass, and all the locks in the world will not stop anyone gaining forced entry in that manner.

Based on my experience I make a number of other important points about security that it may be wise to consider, see my page on security