Window Contacts or Glass Break detectors?

This is a common question from homeowners. Should I install contacts on my windows or install acoustic glass break detectors? Or both?  The answer depends on the specific needs and budget of the homeowner.

Window contacts and glass break devices are both 'perimeter' devices. This means these devices are intended to sound the alarm instantly when the perimeter of your home is breached and/or entered by an unauthorized person or persons. Statistically, 85% of home burglars enter through a door. The proliferation of decorative and window glass in exterior doors has made this route easy and practical for a burglar. Still, windows continue to be used for entry in residential burglaries and window security should always be considered when choosing the components of your intrusion alarm system.


The default installation model for many years has been door contacts on all doors, window contacts on any ground floor windows with motion sensors as a backup system in the home to sound the alarm by detecting unauthorized movement. The known flaw of using window contacts is that the window must be opened to sound the alarm. A savvy crook can simply knock all of the glass out of the window frame before entering-without opening the window or triggering the perimeter burglar alarm. This allows an intruder into your home forcing you to rely on an alarm triggered by a backup device such as a passive infrared motion detector.  A properly installed glass break detector eliminates this issue because it will sound the alarm immediately when the specific sound pattern of glass breaking is detected-before the burglar gains entrance.

Glass breaks are an excellent complement to any burglar alarm system and should be used anytime you have large panes of fixed glass such as picture windows or a sun room. Glass breaks can be a cost effective alternative to window contacts in rooms with 2-3 or more windows or in newer residences with large and wide open common areas. Older residences with small rooms, compact hallways and 1-2 windows in each room may require multiple glass break detectors which may be less cost effective. In a budget constrained situation, window contacts are then recommended with glass breaks in the 'hot spots' or areas most likely to be broken into. A professional security technician can advise you what is best for your home and budget.

Pictured here is a typical wireless acoustic glass break device. These are wall mountable and the typical models can hear glass breaking in an unobstructed 20'-35' 180 degree arc. This device cannot hear through walls or through structural obstructions so each one must be mounted in a room or living area with the front and sides of the detector unobstructed. Acoustic glass breaks trigger the alarm by 'hearing' the sound of glass breaking.



This device is a typical round hard wired glass break detector. These are usually ceiling mounted in the room or area you desire glass break protection.  These also trigger the burglar alarm by 'hearing' the sound of glass breaking.

Window contacts operate when a magnet is separated from the body of the contact by the physical act of opening the window. These can be hard wired or wireless. The hard wired contacts pictured here are typically used for windows and doors.

I welcome your thoughts and concerns. Feel free to contact me at (504) 383-4234 begin_of_the_skype_highlighting            (504) 383-4234      end_of_the_skype_highlighting