It is perhaps not surprising that a large number of burglaries, around 15% (About 100,000 each year), involve no forced entry at all. The thief just walks through an open door or climbs through an open window. And you can see how this might happen. You’re in the back garden on a hot summer’s day and unbeknown to you a thief climbs through an open window at the front of the house and steals your handbag or wallet. It therefore follows that by simply closing windows in unoccupied rooms or by closing them all when you go out you will reduce your chances of burglary and that’s before we even talk about locks! Of course, in the scenario given above you may feel that it is simply not practical for you to keep opening and closing windows just because you happen to be in the back garden. This is perfectly understandable and the advice therefore is to fit the window with limiters so that the window will open only just enough to allow air to flow through the room, but keep the burglar at bay. That said, if you do go out then make sure that you close and lock these windows.
Be aware that your insurance company may not settle a claim for your losses if there was no forced entry. Check the small print.
On a warm humid night many people like to sleep with a window open and providing you have considered the security risks that’s fine. If you sleep on the first floor or above then it is unlikely that a burglar would be able to get in without disturbing you, unless of course the window is accessible as described in Security for existing windows, Windows that should be locked. That said it is still advisable to fit the window with a lockable limiter. If you sleep on the ground floor then you should consider fitting a security grille on the inside of the window that you commonly leave open. It is best to use a hinged or removable grille so that you can clean the window and remember your fire safety – you may have to get out of the window in an emergency.