Windows are left unlocked and open at a much higher rate than doors. An open window, visible from the street or alley, may be the sole reason for your home to be selected by a burglar. Ground floor windows are more susceptible to break-ins for obvious reasons. Upper floor windows become attractive if they can be accessed from a stairway, tree, fence, or by climbing on balconies. Windows have latches, not locks and therefore should have secondary blocking devices to prevent sliding them open from the outside.
For ventilation, block the window open no more than six inches and make sure you can't reach in from the outside and remove the blocking device or reach through and unlock the door.
In sleeping rooms, these window blocking devices should be capable of being removed easily from the inside to comply with fire codes. Like sliding glass doors, anti-lift devices are necessary for ground level and accessible aluminum windows that slide horizontally.
The least expensive and easiest method is to install screws half-way into the upper track of the movable glass panel to prevent it from being lifted out in the closed position. As a deterrent, place highly visible decals on the glass door near the latch mechanism that indicates that an alarm system, a dog, or block watch/operation identification system is in place. Also:
- Secure all accessible windows with secondary blocking devices
- Block accessible windows open no more than 6 inches for ventilation
- Make sure someone cannot reach through an open window and unlock the door
- Make sure someone cannot reach inside the window and remove the blocking device
- Use anti-lift devices to prevent window from being lifted out
- Use crime prevention or alarm decals on ground accessible windows
- Most double-hung windows have thumb-turn locks between the two panels. Do not rely on these—they can be pried open or easily reached through a broken pane. Install locked devices to keep windows from being raised from outside.
- An easy, inexpensive way to secure your windows is to use the “pin” trick.
- Drill an angled hole through the top frame of the lower window partially into the frame of the upper window (figure A).
- Then insert a nail or eyebolt. The window cannot be opened until you remove the nail (figure B).
- Make a second set of holes with the windows partly opened so you can have ventilation without intruders.