A third of burglars get in through a back window. 

• Easily visible locks may deter some thieves, because a window lock forces the thief to break the glass and risk attracting attention. DIY shops sell inexpensive key-operated locks to fit all kinds of window. 
• Fit key-operated window locks to all downstairs windows, those which can’t be seen from the street and easily accessible upstairs window, eg those above a flat roof or by a drainpipe. 
• Even small windows such as skylights or bathroom fanlights need locks. A thief can get through any gap larger than a human head. 
• Remember to remove keys from locked windows and to keep them out of sight in a safe place. 
• Louvre windows are especially vulnerable because the slats can be removed easily from the frame. Glue the slats in place with an epoxy resin and fit a special louvre lock. Better still, replace them with fixed glass. 
• If you are replacing windows, consider laminated glass. 
• As a last resort, consider fitting security grilles to vulnerable windows. 
• Many DIY shops now sell decorative wrought iron grilles. 
• Casement lock make it impossible to open windows without the correct key. 
• Fanlight locks have a metal bolt to secure the metal arm used to open and close the window.