Intruder Alarm Grades

Utilising the correct alarm grade is crucial for all businesses serious about security. Therefore you need to understand Intruder alarm grades, and the grade of system your business requires, depending on the risk level of your property.

Making the correct choice In terms of grade is vital for safeguarding your business, staff and assets. It is also likely that your insurance policy will require a certain grade, in order to satisfy the requirements of your insurance policy.

We recommend that you speak to your insurer to clarify what intruder alarm grade you require, or simply get in touch for a free site survey to discuss your needs.

What are the intruder alarm system grades?

One of the most important aspects of the EN 50131 requirements is the concept of a security grade. For each installation, the grade of the system has to be chosen according to various factors. In the EN the grade is described in terms of the type of intruder and how much effort they would put into a burglary.

There are four intruder alarm grades, which include:

  • Grade 1 Intruder Alarms – Premises unlikely to be targeted by intruders. re unlikely to target the premises.
  • Grade 2 Intruder Alarms – Premises of a higher risk of an intruder or theft due to valuables kept theft on site.
  • Grade 3 Intruder Alarms – Premises at substantial risk from intruders due to high-value contents.
  • Grade 4 Intruder Alarms – Premises has a very high risk of being targeted by organised criminals.

Grade 1 Intruder Alarms – for an installation with a low risk of theft. The property is not likely to attract intruders. It is assumed that a thief is likely to be opportunistic rather than bothering to plan things. The application guide (DD CLC/TS 50131-7). It assumes that an intruder is simply going to break open a door.

Grade 2 Intruder Alarms – for slightly higher risk of theft. The property is likely to have something of interest to an experienced thief. In this case, the intruder is expected to have some knowledge of how alarm systems work and possibly carry tools to overcome a simple alarm system. The thief is likely to check the building for ease of access through doors, windows and other openings.

Grade 3 Intruder Alarms – for a reasonably substantial risk property. There is good reason to assume it may be broken into and might well contain objects of high value. An intruder is likely to gain access by penetrating doors, windows or other openings. The thief could be very experienced with intruder alarm systems and possess many tools and equipment to overcome the system

Grade 4 Intruder Alarms – for very high-risk properties. Intruders could be expected to plan a burglary and have the knowledge and equipment to alter parts of the intruder alarm system to prevent detection. It is assumed that the intruder could gain access by penetration of floors, walls and ceilings. The intruder is unlikely to be working alone.
The EN standard says that it is not necessary to use the same grade of component throughout an intruder system.

What type of intruder alarm grade system do I need?

The type of system will depend entirely on a site survey and risk assessment of the premises in question. Intruder alarm installers will perform risk assessment so that the risk associated with the premises can be fully understood this will then determine the correct grading.

  • Grade 1 Intruder Alarm would only be of interest in domestic properties (without an insurance requirement for an alarm system).
  • Grade 2 Intruder Alarm would be most domestic properties and low-risk commercial (e.g. florists)
  • Grade 3 Intruder Alarm would be for high-risk domestics and most commercial properties (e.g. Newsagent with cigarette sales)
  • Grade 4 Intruder Alarm would be for extremely high-risk domestic and higher risk commercial properties (e.g. bullion stores)

If the installation is a grade 2 then there is no problem using, for example, a grade 3 power supply.

If however, an installer fits a grade 2 component (such as a detector) in a system then that system is limited to grade 2 at best.

What Maintenance is Required?

Routine maintenance requirements typically involve one check per annum for Audible Only systems, and two checks per annum for ARC monitored systems, one of which can be a remote check – subject to equipment compatibility. Find out more about our maintenance here.

Independent family business, Clarion Security Systems is dedicated to ensuring clients have their security systems needs fully met, and are compliant at all times. We offer a full design, installation, service and remote monitoring of advanced electronic security solutions, including commercial intruder alarm systemscommercial access control and business CCTV systems.

Clarion Security systems is an NSI Gold Installer as well as holding the coveted ISO 27001 accreditation. To schedule a FREE site survey please contact us on 08442 084422 or email us today to discuss your needs.


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