Preventing Break-Ins Through Windows

By Duncan Cottrell
While kicking in a door is the most common method of forced entry, windows are also vulnerable, especially when we forget to lock or close them during mild weather. Here are a few things to reinforce them against break-ins.
Typical double-hung windows (where both window sashes slide up and down) have a pivoting lock where the two sashes overlap. The window lock is attached only with short screws, which pull out easily with a pry bar. An easy solution is window pins which are available in a kit from hardware stores, and are inserted into a hole drilled through the wood of both sashes. A special tool, which comes with the kit, is used to pull out the pins to open the window. This product works best on wood windows.
For aluminum or vinyl windows, an alternative is to use dowel rods placed snugly between the sash and the top of the window jamb (the old broom handle in the patio door track, only vertical).
The most effective prevention is fixed metal grilles, or burglar bars. Some people object to the look, but they can be custom designed and painted to match the house to make them nearly invisible. Fire code requires that window bars installed in bedrooms be easy to open for emergency exit. The cheapest is the cheapest: bars that are hollow bend easily.
One of the best products for glass windows and doors is a tough, polyester window security film. It is crystal clear, four mils thick, and is applied from edge-to-edge on the inside of the glass with a super-strong, transparent adhesive. If the glass is broken, like with a brick or baseball bat, the shards won’t fall out. They stay in place because they are bonded to the film, which is too tough to cut or tear. By holding the glass shards in place, the film prevents a broken window from being used as an entry to the home. Very thick versions of security films are used on federal buildings to withstand bomb blasts.
Old windows or doors with individual, small panes of glass set between thin wood crosspieces, or mullions, are not good candidates for security film, because the entire small pane can be pushed out and the thin wood mullions will break, but full-light or half-light doors are easily reinforced.