Multiple physical barriers should be created through appropriate design to ensure physical protection. The following control objectives must be covered in the design of secure premises:
•a clearly defined security perimeter;
•a perimeter strong enough to resist most breaches, with solid external walls;
•external doors protected against unauthorised access;
•physical access to the site or building controlled, e.g. by a reception area;
•signs indicate that access to sites and buildings is restricted to authorised personnel only;
•walls extended from actual (i.e. not raised) floor to actual (i.e. not false) ceiling;
•doors on the perimeter are alarmed and personnel are aware that they must be kept shut.