Vandalism resulting from school building intrusions have cost schools in the United States $500 million a year. Property offenses are the most widespread offenses against schools; strategies available to administrators to combat this destruction include educating students and the community, improving student morale, improving community-school relations, and improving the physical appearance of school facilities. In some cases, immediate measures such as installing a security system must be taken. There are two basic protection systems which use alarm devices. The perimeter system provides protection when all entrances, doors, and vents are equipped with a device that signals their opening or movement. Area protection is provided when a specific area is under surveillance so that movement can be detected. Also available are local and silent alarms. Before school administrators select a protection system, a thorough survey should be made to determine the kinds of equipment available and the kind of surveillance provided and a qualified engineer who has the technical skill to design a security system should be consulted. In the last few years, there has been a return to more traditional methods of combating school intrusions such as use of heavy duty locks, fencing, hall monitors, exterior and interior lighting, and installing door stops in panic exits. Finally, some schools have involved the student body in prevention programs. 9 references.