Window locks

Window locks are an essential part of your home security ‘system’. UPVC windows normally have locking points integral to the window design, as do many designs of modern wooden window. However, older wooden windows were generally made without any real security considerations, other than the use of window stays, and window fasteners, to hold the window in a closed position. It is therefore these types of windows that I’m concerned with here, and below are a selection of window locks that can be used to improve the security of your wooden windows.

Casement window locks

window lockCasement window locks are one of the most popular options for casement windows, as they are incredibly effective whilst being simple to fit. A casement window is the type of window that has hinged opening sections, that operate in much the same way as a door.

These windows may also have opening fanlights which are the smaller opening sections, with the hinges on the horizontal section of the frame, rather than the vertical section.

Casement window locks come in two parts, the striking plate (left) and lock body (right). The striking plate is screwed to the window frame, and the lock body to the opening section of the window. When the window is closed, you simply close the lock body onto the strike plate and secure it in position with the key supplied. Very simple to fit, yet very effective. For more on this type of lock and for fitting, see my guide ‘Fitting casement window locks’.

Concealed mortice bolts

mortice boltConcealed mortice bolts are another option for casements, although they are more commonly used for door security. The fitting process is a bit more complicated than for casement window locks as you actually need to drill a hole in the casement, into which you insert the long bolt section (top), before drilling a corresponding but shallower hole in the frame where the mortice plate (bottom) is positioned.

The orientation of the bolt is vertical, close to the opening edge of the casement, and they are normally fitted in pairs, one on the top edge of the window, and one on the bottom edge. When the window is in a closed position, you use a special key to turn the bolt so that it threads into the hole (mortice), that you’ve made in the frame.

Bear in mind that not all casement windows will be suited to the fitting of concealed door bolts. For more on the principles of fitting this type of lock, see my guide – ‘Fitting a mortice door bolt’.

Casement stay locks

Locking stay pinFitting casement stay locks is one of the simplest security retro-fits that you can carry out on a casement window. Casement stays are the long handles with holes in that are positioned on the bottom edge of windows, which are simply threaded over the ‘pins’ on the window frame allowing you to hold the window securely in an open position, or indeed pull it tight into a closed position.

To increase the security of this system, all that you do is remove the old casement stay pins and replace them with the locking variety. A locking stay pin comes in two parts, the pin (bottom) having a threaded section onto which a locking nut (top) is secured with a key, to hold the stay in position. For more on fitting, see my guide – ‘Fitting casement stay locks’.

Sash window press bolts

sash window lockAs the name suggests, press bolts are designed for use with sash windows, rather than casement windows. Sash window press bolts consist of a lock body (bottom) and receiving plate (top). The receiving plate is fixed to the bottom rail of the top sash, and the lock body is fitted to the top rail of the bottom sash.

When the window is in a closed position, you simply press the bolt into the receiving plate to hold the window securely closed. In order to unlock the bolt, you need to use the supplied key.

For more information on how to fit these incredibly simple locks, see my guide – ‘Fitting a sash window press bolt’.

The window locks shown above are by no means the entire selection that you will find available, but they are some of the most effective options to improve security on your wooden windows. One final point is that when you fit a window lock, remember to keep the key close to the window, in case of an emergency.

  1. andy mccune says:

    I’m looking for a guide that attaches to the sash of a casement window that the locking bar goes thru. Its more like a guide. I have a picture of what im looking for that I can text message it. I can not locate a brand name. thank you Andy

    • Hi Andy,

      I think you may be looking for sash screw locks. If you go to Screwfix and do a search for ‘sash window lock pack of 6’, you’ll see they have a small instruction manual pdf which should provide you with the right info.



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