Perimeter Security Planning: Layers, Standoff Distances & Products
Effective perimeter security is not a single product decision — it is a layered system that uses distance, detection, deterrence, and physical barriers working together.
The Layers of Perimeter Security
- Outer perimeter: Fencing, walls, or natural features defining the site boundary
- Detection layer: CCTV, perimeter intrusion detection systems (PIDS), lighting
- Deterrence layer: Visible security measures that discourage would-be intruders
- Delay layer: Physical barriers that slow down a determined threat
- Vehicle exclusion layer: Certified HVM products that stop vehicles
- Access control layer: Gates, bollards, and access management systems
Standoff Distance: The Most Important Concept
Standoff distance is the space between the vehicle security barrier and the protected asset. The greater the standoff, the more time occupants have to evacuate and the less blast/impact damage reaches the building.
| Standoff Distance | Protection Level |
|---|---|
| Less than 10m | Limited — vehicle impact can still cause structural damage |
| 10–30m | Moderate — most vehicle attacks will not reach the building |
| 30–50m | Good — effective against most vehicle threats |
| 50m+ | Very good — matches government guidance for highest-risk buildings |
Vehicle Exclusion Products by Location
Main Vehicle Access Points
- Automatic rising bollards (IWA 14 rated, remote operation)
- Rising arm barrier with reinforced barrier arm
- Hydraulic road blocker (for highest-threat sites)
Pedestrian Access Points
- Fixed IWA 14 rated bollards at maximum 1,500mm spacing
- STS 202 rated pedestrian gates
- Turnstiles with anti-tailgate detection
Continuous Perimeter
- IWA 14 rated fixed bollard line
- Armco crash barriers (for continuous line where bollard foundations are impractical)
- Certified concrete barriers (for temporary or construction-phase protection)
Integration with Access Control
- ANPR cameras to whitelist authorised vehicles
- Intercom/CCTV for manned verification
- Fail-secure default — barriers rise (block access) on power or system failure
NaCTSO & Police Advice
NaCTSO and the Counter Terrorism Security Adviser (CTSA) provide free site security reviews for crowded places and critical national infrastructure.
Browse our security bollards, barriers, and concrete barriers for all perimeter security applications.