Physical Security — Definition and Components

Definition

Physical security addresses the physical world — the buildings, vehicles, equipment, and people that an organisation must protect from unauthorised access, theft, sabotage, or harm. It is the foundation on which all other security disciplines rest: a facility without adequate physical security cannot be made secure through cybersecurity or policy alone.

Core components

• Perimeter security — fencing, vehicle barriers, lighting, and natural features that define and protect the outer boundary
• Access control — physical barriers (doors, gates, turnstiles), electronic systems (card access, biometrics, PIN), and visitor management procedures
• Surveillance — CCTV cameras, motion detection, and monitoring (real-time vs recorded) that provide situational awareness and post-incident evidence
• Intrusion detection — alarm systems, vibration sensors, glass break detectors that alert to attempted breaches
• Personnel security — pre-employment screening, ongoing vetting, insider-threat detection, and security awareness
• Response capability — the guards, officers, or procedures that convert detection into intervention

Defence in depth

Professional physical security applies the principle of defence in depth — multiple overlapping layers of protection so that the failure of any single measure does not result in a breach. An intruder who defeats the perimeter fence encounters access-controlled doors; an intruder who bypasses access control is detected by CCTV and triggers an alarm response. No single measure is adequate alone.

Physical security assessment

A professional physical security assessment evaluates all components against the specific threat environment — not a generic checklist — and produces a prioritised gap list with actionable recommendations. Mission Support conducts physical security assessments for commercial, governmental, and diplomatic facilities.