Most of the time, perimeter security is what determines how difficult or easy the rest of the security setup is. If you can stop an intruder at the perimeter, then the building(s) behind that perimeter can have a quiet, undisturbed night. If an intruder can cross the perimeter line without challenge, then all of the other security measures in place will be forced to work harder, and most likely, will still be inadequate to protect the building(s).
Perimeter security is usually the easiest security layer to observe and assess. If a site has proper fencing, working perimeter lighting, and gates that a site has that are fully secured, then that site has perimeter security that is taken seriously. On the other hand, sagging fencing, dark spots, and propped-open gates send the opposite message.
Honest Assessment of Your Perimeter
The first job is to walk the perimeter and access it the way an intruder would. Where can somebody climb the perimeter? Where does the lighting fail after dark? Where are the best spots to wait and remain unseen? Where does the perimeter end and back onto vacant land, unlit roads, or other low-overlooked spaces? Where has the boundary been quietly compromised over time by overgrown vegetation, missing fence panels, or a side gate that’s been left unlocked because the key was lost three years ago?
This walk-around is the most useful single hour you can spend before buying anything. Most perimeter weaknesses are fixable cheaply — they exist because nobody’s looked recently.
Fencing Options Across The Range
Timber close-board fencing and standard chain-link at the domestic range give you a boundary marker and some limited resistance to a determined climber. Useful for the low-risk residential, not suitable where the threat is greater.
For commercial sites, weldmesh and palisade fencing step up the resistance quite a bit. Weldmesh is more challenging to climb and cut, and palisade i e. vertical steel pales with pointed/splayed tops — has been a popular choice for industrial sites as well as providing visible deterrence.
High-security sites use systems like 358 mesh fencing, (so called as it has a 76.2mm x 12.7mm openings) and is very difficult to climb or cut. Beyond that, specialist fencing that is rated under LPS 1175 is meant for critical infrastructure and the upper ends of commercial needs.
Moving to Gates.
Fencing has more safety mechanisms than gates. Reading EN 13241, EN 12453 and the Supply of Machinery (Safety) Regulations, a powered gate has to be designed, installed and sustained, so it cannot crush, trap or strike someone using it.
If you are purchasing, or inheriting, an automatic gate, the questions are; when was the last gate safety inspection, does it currently have force testing, is there evidence for compliance. Gates that look ok, may be operating outside the regulations, and the liability when something goes wrong is with the operator.
Barriers to control traffic or barriers to stop a vehicle attack
Barriers designed to control traffic and barriers designed to stop vehicle attack have a significant difference. For example, a standard raising arm barrier is designed to control traffic and would stop a compliant driver, but would not stop a non-compliant driver.
Hostile vehicle mitigation products that have been tested and rated to PAS 68 or IWA 14, where ratings are given by the mass of the vehicle and the speed at impact (example: M30 rated to stop a 7,500 kg vehicle going 30mph). For public buildings, sensitive infrastructure, and even some retail, where a vehicle-borne attack is a realistic threat, this is the rated kit that does the job. For all other places, traffic management will do.
Properly done lighting
Security lighting is done incorrectly more often than correctly. Hundreds of bright light fixtures positioned at the wrong angles will cause deep shadows where there should be cover and dazzling to anyone looking at the site from outside including your CCTV.
Proper security lighting is worked at angles where people actually will be moving, and works with your CCTV instead of against it. Sensors are used instead of constant illumination. Light pollution, especially in rural or residential places, is when lighting is done correctly.
Where the security provided by fencing is insufficient, anti-climb features are used. The upper sections of a fence can be fitted with climbing-resistant materials. Some styles of fencing can be fitted with climbing-resistant materials and topped with painful and difficult to traverse features. Systems of detection and reaction fence line systems use vibration sensors or beam detectors that will alert before someone has already traversed the area and potentially the fence.
Ultimately, the choice of materials and systems depends on the function of the area behind the perimeter, and how much time you need to.
The most common mistakes
The most common historic failures include specifying products from a catalog instead of a site visit, treating fencing as installed and finished, not performing maintenance, lighting that causes blinding and creates shadows, automatic gates that operate without safety and security approvals, and rated vehicle barriers that signed traffic management systems. Perimeter security only works as a system, meaning every component has to incorporate a supporting function.