Taking A Layered Approach To Building Security

27 May 2022

Critical National Infrastructure Building Protection

When looking to protect a building and site from intrusion, it is always best to consider a layered approach. By this we mean installing layers of security systems from the perimeter into high security areas within a building. One of the areas we specialise in is high security and critical infrastructure sites.

What is Critical Infrastructure?

Critical infrastructure is a term used to describe assets and systems essential to the functioning of society and the wider economy in general. Utilities including electricity, water, gas and telecoms are prime examples.

Each of these utilities require not just cyber secure, but physical security to prevent unauthorised access. If we consider the UK’s electricity generation, transmission and distribution system, there are thousands of assets to protect including solar PV farms and substations. Entry may be sought for all sorts of reasons including a desire to vandalise or to cause supply disruption (terrorism) or simple theft in the form of spare cables and other metal materials.

Perimeter Intrusion Detection Systems

Sometimes referred to as a PIDS, a perimeter intrusion detection system is a monitoring solution for perimeter fences. Sabre from Remsdaq is a classic example. This is a fibre optic-based solution that relies on the running of a fibre optic cable along the length of the perimeter fence which is connected to a Sabre panel. The system monitors for changes in the light pattern to detect cut or climb events on a protected fence. The signal alarms can be reported to a third-party application an access control solution.

Building Access Control Solutions

An access control solution provides a way to monitor and control who has access through specific barriers and doors to a site, building and areas within. The system consists of several components including door controllers, readers and an access control database that stores user details and credentials.

For sites with a perimeter fence, the entrance/exit gates or barriers can be controlled via access control. Some form of carD reader or ANPR (automatic number plate reader) can be connected to read a credential which is then checked to the access control database. If authorised, entrance (or exit) is approved. If not permission to enter or exit is denied. In either event, a record is maintained in the access control database for audit purposes.

Here the access control provides a secondary layer of site protection, controlling entry onto site. The next layer of security is at the building entrance. Here the doors and locks are controlled by the access control system. A credential in the form of an access control card or mobile phone credential is presented to a door reader or door reader / keypad if multi factor authentication is in use. The credential is checked to the database and permission to enter granted or denied.

CPNI Access Control Systems

Remsdaq supplies a CPNI access control system for use on government buildings and infrastructure requiring a CPNI certified solution. Referred to as EntroWatch CS,  this version of our popular EntroWatch access control solution is a ‘Certified Secure’ version comprising of the EntroWatch access control software and specially configured hardware installation to ensure the high level of system robustness required for ultra-high security government installations.

Video Monitoring Systems

An additional layer of security can be added to the site through the use of an integrated CCTV camera system. With suitably placed cameras, any alarm generated by the PIDS can be immediately zoomed into and investigated, day or night. The system will of course also be recording 24/7 and so can provide evidence of intrusion or a malicious act.

CCTV camera feeds can be also be viewed within a compatible access control solution. Remsdaq Entro systems can take camera feeds for viewing inside EntroWatch software using the Milestone XProtext VMS plugin. Increased functionality, including pre and post door event video viewing is available when a more integrated approach is taken. In instance using a compatible HIKVision camera system with EntroWatch.


Threats to critical infrastructure and general buildings continue to evolve and for this reason it is important to continuously assess the viability and intrusion protection features of any layered security system. At the very least it is important to review security measures at least once a year and if necessary, use an external security consultant to carry out this task. They will bring an external view onto the existing system and can advise on the latest security threats and counter measures.