Security Fencing vs Bollards: Choosing the Right Perimeter Protection

Perimeter security is one of the most important — and often most overlooked — aspects of site safety and security planning. Two of the most common physical security measures are security fencing and bollards, but they serve different purposes and are often best used together.

What Security Fencing Provides

Security fencing creates a continuous physical barrier around a perimeter. It:

• Defines boundaries clearly
• Creates a psychological deterrent
• Slows or prevents pedestrian intrusion
• Supports detection systems (CCTV, sensors)
• Provides privacy and concealment

However, standard security fencing does not stop vehicles — a car or van can crash through most 2.4m palisade or mesh fencing without significant speed reduction. For vehicle threat mitigation, bollards or vehicle-rated barriers are required.

What Bollards Provide

Bollards create point barriers that stop or deflect vehicles. They:

• Stop vehicles at specific access points
• Protect specific assets (buildings, infrastructure)
• Allow pedestrian passage while blocking vehicles
• Can be rated and certified for specific vehicle/speed combinations (PAS 68)

However, bollards don't create a continuous barrier — they require specific spacing to prevent vehicles driving between them, and they don't address pedestrian intrusion in open areas.

Layered Perimeter Security

Best-practice security design uses multiple layers:

1. Outer perimeter: Security fencing (palisade, mesh, razor wire) — pedestrian deterrent
2. Vehicle entry points: Bollards, rising barriers or vehicle-rated gates — vehicle access control
3. Building facade: Anti-ram bollards at specific vulnerable points
4. Secondary barriers: Internal crash barriers, warehouse bollards — operational protection

For CNI and High-Security Sites

The Centre for the Protection of National Infrastructure (CPNI) provides guidance on integrated perimeter security. Their Perimeter Security guidance document recommends:

• Standoff distance from building to perimeter barrier: minimum 30m to protect against vehicle bombs
• Vehicle-rated barrier systems throughout, not just at entrance points
• Layered detection and delay systems

FAQ

What type of fencing is most secure?

For anti-cut and anti-climb resistance, rigid mesh (358/LPS 1175-rated) or welded wire mesh rated to LPCB LPS 1175 security ratings provides the best combination of durability, visibility and intrusion resistance.

How far apart should security bollards be spaced?

To prevent a standard passenger car from passing between bollards, maximum spacing is 1.2 metres (centre-to-centre). For larger vehicle exclusion, reduce spacing accordingly or use a continuous vehicle-rated barrier.

Can CCTV replace physical security barriers?

No. CCTV is a detection measure, not a physical protection measure. It can help identify and prosecute after an incident but does nothing to prevent vehicle impact or intrusion in the first place. Physical barriers and CCTV work best together.