Physical Security and Access Control
Perimeter first
The boundary is the first layer: fencing to the required height with anti-climb topping, a clear zone on both sides, locked gates, and lighting at gates, walkways and vehicle checkpoints. Signage should state entry conditions and search policy. The building envelope follows: solid doors, deadlocks, hinge bolts, grilles or laminated glass on ground-floor windows, and controlled roof access.
Access control in four steps
Identify the person, verify the claim (photo ID, appointment list), authorise the level (visitor, staff, contractor), and record entry and exit. Use badges with photo and colour coding, visitor passes worn visibly, escorts for non-staff, and a key register showing issue and return. For strongrooms, cash rooms and server rooms, apply the two-person rule and anti-passback so one card cannot admit two people.
Searching and patrolling
Search authority must be written in post orders, applied equally, conducted with a witness and with consent where the law requires it. Patrols should mix fixed and random timings, use clock points or QR checkpoints, and vary routes so they are not predictable.
Worked example. Staff hold the door for colleagues and tailgaters enter. The guard installs a turnstile with anti-passback, adds a sign saying one person per entry, and challenges anyone without a visible badge. Reasoning: tailgating is a design and culture problem, so engineering plus a polite challenge works better than a camera that only records the breach.
Traps that cost marks
Holding the door for a senior visitor, writing a PIN on the card, assuming biometrics never fail, and searching a bag without consent, witness or a written policy.