Intruder Alarm Grades Explained: Which Grade Do You Need?

If you have ever had a quote for a burglar alarm, or read the small print on a home or business insurance policy, you may have come across the phrase "Grade 2" or "Grade 3". These grades are not marketing labels. They come from a British and European standard, and they describe how well an alarm system is designed to stand up to an intruder.

This guide explains what intruder alarm grades mean, which grade usually suits homes and businesses, and how grades link to insurance and police response.

This article is general guidance only, not legal or insurance advice. Always check your own policy and requirements.

What are intruder alarm grades?

Intruder alarm systems in the UK are designed around the European standard BS EN 50131. Part 1 of that standard sets out the system requirements and splits systems into four security grades, from Grade 1 (lowest risk) to Grade 4 (highest risk).

Each grade is based on the type of intruder the system is expected to face: how much they know about alarms, how well prepared they are, and what tools they might bring. The higher the grade, the harder the system is to defeat, tamper with or bypass.

In the UK, the standards are applied through a BSI document called PD 6662, which acts as an "umbrella" scheme covering how intruder and hold-up alarms are designed, installed, commissioned and maintained. The current version, PD 6662:2017, came into effect on 1 June 2019.

The four grades in plain English

• Grade 1 – low risk. Assumes an opportunistic intruder with little or no knowledge of alarms, who might simply try to force a door.

• Grade 2 – low to medium risk. Assumes an intruder with limited knowledge of alarms who will check a building for easy ways in through doors, windows and other openings.

• Grade 3 – medium to high risk. Assumes an intruder who may be experienced with alarm systems and carry tools and equipment to try to defeat them.

• Grade 4 – high risk. Assumes a well-planned attack by people with the knowledge and equipment to tamper with system parts, possibly entering through walls, floors or ceilings, and unlikely to be working alone.

Which grade do homes usually need?

For most houses and flats, Grade 2 is the usual choice. It is the grade most commonly fitted to homes and is often what insurers look for when they ask for an alarm.

Grade 1 systems are mainly of interest where there is no insurance requirement for an alarm at all. At the other end of the scale, higher-value or higher-risk homes may be advised to have a Grade 3 system, particularly where an insurer asks for one.

Which grade do businesses usually need?

Commercial premises vary a lot, so the right grade depends on what you keep on site and how attractive it is to thieves.

• Lower-risk premises, such as a small office or shop without high-value stock, may be suited to Grade 2.

• Many commercial and industrial sites, including those holding valuable stock, tools or equipment, are typically specified at Grade 3.

• Grade 4 is reserved for very high-risk sites, such as some financial, government or critical infrastructure locations.

Your insurer may set a minimum grade as a condition of cover. If they do, that grade becomes the floor for the whole system.

A system is only as strong as its weakest part

An alarm system's grade is limited by the lowest-graded component in it. If a Grade 3 control panel is connected to a Grade 2 detector, for example, the system as a whole can only be described as Grade 2.

Using a higher-graded part in a lower-graded system is fine, but not the other way round. This is why it is worth asking your installer to confirm the grade of the complete system, not just the control panel.

Grades, insurance and police response

Grades matter most when you want your alarm to be taken seriously by your insurer or the police. A few points are worth knowing:

• Insurers may require an alarm, specify its grade, and ask for it to be installed and maintained by an approved company such as an NSI Gold or Silver installer.

• Your cover may be affected if a burglary happens while the property is empty and the alarm was not set.

• For a police response, a monitored system must meet National Police Chiefs' Council (NPCC) requirements. Monitored systems installed since June 2019 need to conform to PD 6662:2017 and BS 8243, the standard covering how alarms are confirmed before police are called.

• Your installer should explain how to get a Unique Reference Number (URN), which registers the system with your local police force.

• In England, Wales and Northern Ireland, immediate police response is withdrawn after three false alarm calls in a rolling 12-month period, and is only reinstated once the cause has been fixed.

A bells-only (audible) alarm can still be a useful deterrent, but it does not on its own qualify for a planned police response. Some forces also require at least two keyholders who can get to the premises promptly.

Questions to ask before you buy

Whether you are protecting a home in Alton or a warehouse near Farnham, it helps to go into a quote with a few clear questions:

• What grade will the complete system be, and is that what my insurer requires?

• Will I receive a Certificate of Compliance to PD 6662?

• Is the company approved by an inspectorate such as the NSI or SSAIB? You can check NSI-approved companies on the NSI Company Finder.

• If the alarm is monitored, is the Alarm Receiving Centre approved, and what police response level can I expect?

• How will false alarms be kept to a minimum, and how often will the system be maintained?

The bottom line

Alarm grades give you a simple way to compare systems on like-for-like terms. For most homes, Grade 2 is the sensible starting point; for many businesses, Grade 3 is more appropriate. The most important thing is to match the grade to your actual risk and to what your insurer expects, and to make sure every part of the system meets that grade.

If you would like a second opinion on your current alarm, or advice on the right grade for a new installation, Protect CSM carries out surveys and installations across Hampshire and Surrey. Call us on 01420 375376 or email info@protect-csm.co.uk.