We are often asked which windows in people’s homes are most likely to be smashed by a thief in a burglary.
As described in my post about the typical residential burglary, most crooks will use the front or back door in order to gain entry to a home.
Although the most common method of entry, at least on the Westside of Vancouver, is to use a crowbar or screwdriver to pry the front door open, another very common tactic is to smash a pane of glass in order to gain access.
However, rather than smashing a window in order to climb through the broken glass, the typical burglar will often smash a window in order to allow them enough room to reach their hand in and turn the doorknob or open the window latch. As a result, the small panes of glass on either side of the front door as well as the half windows found in many back doors are at the highest risk for being smashed in order to gain entry, such as the one in the photo above.
In my experience, I have seen virtually every method of gaining entry… and although I have seen sliding glass doors and full size windows smashed in order to step into a home, those circumstances are certainly rare. The vast majority of smashed windows end up looking like the photo above… where the glass is smashed in order to reach in and open a door. As a result, there are a few options that you should consider when trying to protect your home from entry through a window.
These include:
1. Double-Sided Deadbolts. Consider installing double-sided deadbolts on your doors that have windows. A double-sided deadbolt requires a key on both the inside and outside in order to unlock the door (see the photo below for an example)… which makes it impossible for a crook to simply break the glass, reach in and unlock the door. 
While very effective in reducing the risk of burglary, double-sided deadbolts do create a life safety threat in the event of a fire in your home. In fact, double-sided deadbolts are against the Fire Code in most jurisdictions. Although a risk in any home, this is of particular concern in homes with small children, elderly or disabled individuals who may not be able to get to a key in time in order to unlock the door in a fire. If you elect to use double-sided deadbolts, you may choose to engage it only when you are away from the house and have a second deadbolt, with a single sided lock for when you are home.
Glass doors can still be very safe and you should not feel that you have to sacrifice aesthetics for security. In, the picture above, the door is protected by laminated glass, a glassbreak detector as well as a high security Mul-T-Lock double-sided deadbolt (and Provident monitoring with immediate response).
2. Glassbreak detection. Provided that a double sided deadbolt has been used, a glassbreak detector is often the difference between a crook trying to find another way to break in and simply giving up early. As discussed in an earlier post, glassbreak detectors are the only devices that we can install inside of a home that will detect an intruder while they are still standing outside. (There are options like exterior beams and cameras that can be installed on the exterior of your home as well.)
3. Upgrade your glass. In my own home, all of our main floor glass was replaced with factory installed laminated glass when we renovated a few years ago. This means that rather than a piece of glass breaking into a million pieces when struck like in the photo below, 
the glass will break like a windshield in your car. A crook will need to expend siginificantly more effort to break through the glass than he would for regular glass. When coupled with the use of glassbreak detectors, this can provide a significant deterrent.
Please note that laminated glass (or window film, which is described below) requires special glassbreak detectors.
4. Window Film. Window film is an alternative to having to replace your windows with laminated glass. Instead, a thin layer of film is applied to the existing glass in offer additional protection.
While I am not a huge fan of window film for the simple reason that it must be installed by an absolute professional in order to offer any real value, it can, if installed properly, significantly increase the strength of your windows.
Unfortunately, I have seen many poor window film installations which have resulted in a home or business owner inadvertently making it easier for a crook to break in. Unless the window film is installed perfectly, a crook can simply smash the glass without the risk of being cut because all of the glass stays together in one flexible piece.
Once smashed, in a poor installation, the crook can gently push the smashed pane until they are able to grab the sides and then neatly lift the smashed pane, in one piece, out of the frame. I have been on the scene of at least a dozen burglaries like this.
5. Bars or Roll Shutters. The last resort for many people who have been repeatedly victimized is to invest in roll shutters that automatically close when they arm their system. Shutters do not need to be as ugly as they sound… in fact, newer models installed by companies like Talius are not as offensive as you might think (at least when they are up).
However, in the spirit of five-minute proofing, if you decide to install roll-shutters it is very important that the shutters themselves are connected to your alarm system so that the second someone tries to pry them open, the alarm trips.
Similarly, if a decision to install bars is made, it is very important that the bars be installed on the inside of your windows in order to allow for your alarm to trip before a crook has a chance to start to try and defeat the bars. However, as bars are rarely the most attractive option for window security, most people choose to have them installed only in the basement of their home. I’ll have a post soon about what to look for when considerinig window bars in your basement.
For information about protecting your windows from being pried open, check out this post from a couple of months ago.