Perimeter Security Measures.
A. Perimeter protection is the first line of defense in providing physical security for a facility. This can be accomplished by installing fences or other physical barriers, outside lighting, lockable gates, intrusion detectors, or a guard force. Perimeter protection also includes walls, lockable doors and windows, bars and grills, and fire escapes.
B. In addition to defining the physical limits of a facility and controlling access, a perimeter barrier also creates a physical and psychological deterrent to unauthorized entry. It delays intrusion into an area, making the possibility of detection and apprehension more likely. It aids security forces in controlling access and assists in directing the flow of persons and vehicles through designated entrances.
C. Every vulnerable point should be protected to deter or prevent unauthorized access to the facility. The roof, basement, and walls of a building may contain vulnerable points of potential entry. A security survey of the perimeter should address manholes and tunnels, gates leading to the basement, elevator shafts, ventilation openings, skylights, and any opening 96 square inches or larger that is within 18 feet of the ground.
D. The extent of perimeter controls will be determined by the senior facility manager, based upon a comprehensive physical security survey (Appendix C). The survey report should recommend perimeter controls to the facility manager.
Physical barriers may be of two general types, natural and structural. Natural barriers include mountains, cliffs, canyons, rivers, or other terrain difficult to traverse. Structural barriers are man-made devices such as fences, walls, floors, roofs, grills, bars, or other structures that deter penetration. If a natural barrier forms one side or any part of the perimeter, it in itself should not automatically be considered an adequate perimeter barrier, since it may be overcome by a determined intruder. Structural barriers should be provided for that portion of the perimeter, if required.