Most businesses start perimeter security with a single idea: a fence, a camera or a gate. The sites that stay secure treat it differently. They think in layers, so that each part supports the others, and a failure in one place does not leave the whole site exposed.
The four jobs of perimeter security
- Deter: make the site look like a hard target, so attackers choose somewhere else.
- Detect: know quickly that someone is trying to get in.
- Delay: slow them down so that there is time to respond.
- Respond: have a plan so that someone acts on what has been detected.
A fence on its own only delays. Without detection, nobody knows it is being attacked. Without a response, detection achieves nothing.
The layers
1. The boundary
Fencing, walls and gates mark the edge of your site, deter casual entry and delay a determined intruder. The height, design and any security rating should match the risk. See our guide to security fencing types.
2. Gates and vehicle control
Entrances are the weak point in most perimeters. Keep the number to a minimum, and control them with gates, barriers and bollards and an access control system so you know who comes and goes.
3. Lighting
Lighting deters, makes intruders feel exposed and allows cameras to produce usable images. It is often the cheapest improvement of all.
4. Detection
Perimeter intrusion detection, such as fence sensors, beams or ground sensors, tells you when the boundary is attacked, so you can respond before they are inside. It needs to be designed to suit the type of fence and the conditions.
5. CCTV
Cameras verify alarms, record evidence and let you see what is happening. They are most effective when they are linked to detection, so that an alert brings up the right camera automatically. See our CCTV service.
6. Building and internal security
The last layers are the intruder alarm and internal access control, which protect the building itself if the outer layers are beaten.
Where to start
- Do a risk assessment. What are you protecting, what are the likely threats and how could they get in?
- Walk the boundary. Look for gaps, damaged fencing, climbing aids such as stacked pallets and overgrown vegetation that hides activity.
- Fix the cheap things first. Lighting, tidy storage and repairing damage often make a big difference quickly.
- Add detection and cameras where they matter. Cover entrances, blind spots and the areas that contain your most valuable assets.
- Plan the response. Decide who is alerted, what they do and how quickly.
Keep it working
A perimeter system degrades over time. Make routine checks part of your calendar and keep a maintenance contract in place for detection, cameras, gates and lighting.
We design and install perimeter systems for sites across London and the Home Counties. See our perimeter security service, or call 01296 614440 for a free survey.
Frequently asked questions
What is layered security?
It means using several complementary measures, such as a fence, lighting, detection, cameras and access control, so that if one fails or is bypassed, the others still deter, detect and delay an intruder.
What should I do first?
Start with a risk assessment of your site: what you need to protect, how it could be attacked and where the weak points are. That tells you what to spend money on first.
Does a perimeter system need maintenance?
Yes. Fences get damaged, vegetation grows, lights fail and cameras drift. Regular checks and servicing keep each layer doing its job.