Fire alarm systems

what do i need to know...?

fire alarm systems

UK fire alarm regulations can feel less than straightforward if you’re not a fire safety professional.  A simple guide to the latest UK fire alarm legislation follows

Fire alarm regulations form part of ‘The Regulatory Reform (Fire Safety) Order 2005’, known as the ‘RRO’.

In addition, the UK government recommends that all fire alarm and detection systems should be installed and maintained in accordance with the relevant British Standard, BS 5839 (the information below is based on BS 5839).

Despite the regulatory literature, as a fire safety company of many years’ standing, we know that there is often confusion around the exact requirements of UK fire alarm legislation.

As well as legisation we've provided a brief guide on fire alarms in addition. More information from the HSE can also be found here

Do I need a fire alarm?

Current UK fire alarm regulations state that all business premises must have ‘an appropriate fire detection system’.

This basically means that an outbreak of fire can easily be detected and occupants can easily be warned.

This does not necessarily mean that all business premises will need a fire alarm system.

You are unlikely to need a fire alarm system if all of the following statements are true:

  • Your premises are small, simple, and single-storey or open-plan
  • You don’t store any high-risk substances, such as chemicals
  • You don’t undertake any high-risk activities, such as cooking
  • You don’t have any vulnerable occupants, such as the very young, elderly or disabled
  • A fire would be easily spotted if it broke out anywhere in the premises
  • A shout of ‘fire!’ would be easily heard by all occupants

If one or more of these statements does not apply to your business, then you probably need a fire alarm system.

If you are in any doubt, then your Fire Risk Assessment should specifically state whether you should or shouldn’t install automatic fire detection.

If you don’t have a Fire Risk Assessment then we would recommend you carry one out first, as this is the cornerstone of your business’s fire safety plan


What type of fire alarm do I need?

There are 3 main types of fire alarm system: conventional, addressable, and wireless:

Conventional Fire Alarm
–    divides your premises into broad zones
–    in the event of an alert, the fire alarm panel identifies the zone, but not the precise area
–    most suitable for smaller or lower risk environments

Addressable Fire Alarm
–    each individual device has its own unique electronic address
–    if one activates, the fire alarm panel tells you precisely where the problem is
–    most suitable for larger or higher risk environments – e.g schools, care homes, hospitals

Wireless Fire Alarm
–    uses a secure wireless link between the sensors and the fire alarm panel
–    typically works like an addressable system, just without the wires
–    most suitable for premises which don’t want lots of cable – e.g. churches, historic buildings

UK fire alarm legislation doesn’t specify exactly which each type of fire alarm system should be used in which types of premises, again, it comes down to what is ‘appropriate’ for your particular business.

To make sure you get the right fire alarm system to meet UK fire alarm regulations, it is recommended that you use a reputable fire safety company to design it.

You should also make sure they design to BS 5839 specifications (the relevant British Standard), otherwise you may not be covered for regulatory or insurance purposes.

What are fire alarm system ‘grades’ and ‘categories’?

This is a complex area but basically ‘grades’ and ‘categories’ respectively define how your fire alarm system should be constructed (grades), and which areas of your building it should cover (categories).


Fire alarm grades run from ‘A’ through to ‘F’, with ‘A’ being the highest grade and ‘F’ being the lowest.

Residential buildings can usually meet UK fire alarm regulations with a lower-grade system (D-F). These are not wired into a central control panel, and may not have back-up battery power.

However, businesses generally need a more substantial system to comply with UK fire alarm legislation – from ‘A’ through to ‘C’ grade.

At a very simplistic level, these higher-grade systems are wired into a central fire alarm panel, connected to the mains power supply, and also have a back-up power supply.


There are 2 main categories:

–     Category ‘P’ systems – protect property
–     Category ‘L’ systems – protect life

  Category P Fire Alarm Systems – Property Protection
P1 P1 protects the whole building.
P2 P2 is installed in defined parts of the building only.

Category P systems are usually installed at the request of insurers.


Category L Fire Alarm Systems – Life Protection
L1 L1 provides for Automatic Fire Detection (AFD) to be installed into all areas of a building.
L2 L2 provides Automatic Fire Detection (AFD) as defined in L3 as well as high risk or hazardous areas. Examples of this could be Kitchens, boiler rooms, sleeping risk, storerooms if not fire resistant or if smoke could affect escape routes.
L3 L3 Automatic Fire Detection (AFD) with smoke detection should be installed on escape routes with detection in rooms opening onto escape routes.
L4 L4 provides Automatic Fire Detection (AFD) within escape routes only.
L5 L5 is installed in building with a specific risk that has been identified. An example of this would be if there was an area of high risk that requires detection the category would be L5/M.

Which grade and category of fire alarm system you need is very much dependent on the nature of your business and the size and layout of your premises.

Again, the grade and category of fire alarm system you need should be specified in your Fire Risk Assessment, or advised by whoever is designing your fire alarm system (don’t forget to make sure this conforms to British Standard BS 5839.)

Who can install a fire alarm?

UK fire alarm regulations make no requirement as to who can install a fire alarm, other than that they must be ‘competent’.



This therefore means that the person or company who installs your fire alarm should:

–    understand the various types of fire alarm system and how they work
–    be familiar with the main makes and model of fire alarm
–    be able to identify which grade and category of fire alarm system you need
–    be able to design a fire alarm system to meet the grade and category requirements
–    have a good understanding of British Standard BS 5839
–    be able to design a system to meet BS 5839 requirements
–    have sound electrical knowledge

Where will I find additional guidance about the required standards for my building?

If you are responsible for specialised housing – for example, sheltered housing, extra care housing, or supported housing for people with common characteristics, such as learning disabilities and mental health problems – NFCC Specialised Housing Guidance is helpful.

If you need information about requirements for purpose-built dwellings such as blocks of flats, the Local Government Association (LGA) provides useful information in their downloadable publication Fire safety in purpose-built flats.

If you are looking for more information about shared houses, bedsits and HMOs, please see this LACoRS guidance.

The website is here – it provides additional guidance for most circumstances.

What happens if you aren't compliant?

If it's found that there's something wrong, then action ranging from providing information and advice to prosecuting those responsible in a court of law is available. For serious offences, you could be fined and/or imprisoned.