Many hollow doors can be easily broken through. A metal lining on the inside of an exterior door is valuable to prevent drilling, sawing, or kicking through. Door hinges must always be on the inside and designed so that hinge pin cannot be removed from the outside. Secure sliding glass doors with commercially available bars or locks. Alternately, put a wooden dowel or broom handle in the door track.
Burglars look for sliding glass doors because they are the easiest to open.
The center thumb-turn locks on many standard windows can be easily pried open or reached through a broken pane. Glass block windows offer excellent security for basement windows. Lock up every time you go out, even if it's only for a few minutes. Almost 50 percent of burglars enter homes or property through unlocked doors or windows. Locks on doors should be placed at least 40 inches away from windows, glass panels, and other potential openings such as mail slots.