Repeat burglars generally find a method of entry that works consistently and then stick with it.
Here are some methods of unlawful entry in burglaries:
What type of door is easiest for a burglar to break through? That would be a hollow door, because these are exceptionally easy to kick in.
Sliding doors are also vulnerable to being lifted out of their tracks, and putting in a dowel to help prevent the door from sliding is not much help in this situation. A pin lock involves drilling a hole at an angle through the overlapping frames in the top center of the door. Then you can insert a pin with a clasp to help keep the door from sliding or being lifted off the track. Pin locks are inexpensive and can be installed using a drill and screwdriver by a homeowner with DIY skills.
With solid doors, however, the type of door itself isn't that big a factor in whether a burglar gains entry. Battering ram tests show little difference among door materials (wood, metal or fiberglass) for strength. Doors typically fail due to the doorjamb splitting near the strike plate of the lock. High-quality strike plates and deadbolts can make a solid-core door more resistant to being kicked in.
If you're replacing windows, look for PVC-framed windows that are ISO certified (which will be stated on the box).
Use window stops/locks to help prevent windows from being opened more than a few inches (that would allow someone to reach in and remove a blocking device). You can get window stops that have a moveable frame and that lock into place. Another alternative is to drill a hole through both the window frame and the frame it sits in and install a nail or screw to lock the window shut permanently.
Keep valuable items out of view through ground floor windows, and invest in blinds or drapes to shield the interior of your home from view. Tinted window film is another option for blocking the view into your home.
Standard spring locks can be defeated in seconds using a small piece of flexible plastic. Deadbolts offer greater security, but they can be overcome as well. Choose deadbolts with at least a one-inch throw and that come with a reinforced strike plate. An ordinary strike plate is one of the most vulnerable points in an exterior door. If your deadbolt does not come with a reinforced strike plate, you can purchase one separately. When installing your strike plate, use a mounting screw that's at least three inches long so that the strike plate is secured to both the doorjamb and the wall stud. Learn more about lock safety.
Securing your home's windows and doors is critical to overall home security, even if you have a sophisticated home security system. Once you have made sure that all exterior doors, windows and sliding glass doors have enhanced security in the form of reinforced strike plates, deadbolts, window stops and pin locks, you may choose to take the additional step of having a monitored home security system installed.
When homeowners take a "layered" approach to home security, all security measures reinforce each other and make it clear to burglars that they will have a hard time getting in. When most burglars encounter a home with multiple security layers, they often decide to try their luck somewhere else.