top of page

Fire Detection & Alarm Systems


For the purposes of this Technical Bulletin a fire detection and alarm system is referred to as AFA.

The main standard for fire alarm installations in premises other than domestic property is BS 5839:2017: Fire detection and alarm systems for buildings – Part 1: Code of practice for design, installation, commissioning and maintenance in non-domestic premises. (Fire alarm installations in domestic premises fall under BS 5839-6).

Fire alarm systems will be encountered in most industrial and commercial buildings, mainly as a result of the requirements of Building Regulations and/or the outcome of a risk assessment in compliance with the Regulatory Reform (Fire Safety) Order, or earlier fire safety legislation. In the majority of cases, these will have been installed to satisfy life safety objectives, normally comprising manual call points throughout the premises, together with detectors in selected areas – typically Category M/L5 – M/L3.

Systems will also be designed and installed which are intended for property/business protection as well as satisfying the objectives of life safety. These would normally be installed to a Category P1 standard, providing total coverage of the premises. Alternatively, for complex risks, a Category P2 installation providing partial coverage only may be encountered when forming a component of a “fire engineered” solution, often with sprinklers and/or other forms of active and passive protection.

Where the system has been installed to satisfy both life safety and property protection, this should be reflected in the system Category (e.g., a Category L3/P2 system, etc.).

Category L1 & P1 systems for all intents and purposes are the same, the only differences being that an L1 system has an additional requirement for smoke detectors in escape routes and enhanced alarm sounders.

BS 5839 Part 1 – Design Considerations

The Fire Industry Association (FIA) has published an excellent guidance document on the selection and specification of fire alarm categories which, together with their accompanying Fact Files  are considered essential reading for all Consultants unfamiliar with BS 5839. These documents can be downloaded from the FIA website (This is an excellent website and by signing up for FIA News is an ideal way of keeping up to date with current issues and developments in the field of fire safety.)

Dealing with BS 5839 in general, there is a wealth of guidance information available on the internet of which  is a particularly useful link.

The latest version of BS 5839: Fire detection and fire alarm systems for buildings – Part 1: Code of practice for design, installation, commissioning and maintenance of systems in non-domestic premises came into effect on 31 August 2017. This new edition introduces a number of technical changes, the key measures of which include:

  • The revision adopts latest industry thinking and new technologies including added guidance on the use of video fire detection and multi-sensor fire detectors with the aim of reducing the incidence of false alarms.

  • To reduce the chance of either malicious or accidental activation it is recommended that all manual call points are fitted with a protective cover.  Fitting protective covers to manual call points is now the default recommendation.  A “variation” to the Code of Practice must be declared if covers are not fitted.

  • Means of safe isolation for maintenance purposes must be provided; however, there is no longer a requirement to provide double pole isolation adjacent to control equipment and power supply units.

  • Additional guidance including a new annex addressing the selection and application of fire detectors has been incorporated.

Some of the key considerations incorporated in the previous version of BS5839: Part 1 (2013) which have been carried across to the new edition of the standard include:

  • Where occupants of a building are going to need assistance from staff to evacuate the building (e.g., in residential care premises and hospitals), the fire detection and fire alarm system should be addressable if the building has facilities for more than ten people to sleep;

  • In residential care homes, facilities should be provided for automatic transmission of alarm signals to an alarm receiving centre;

  • In residential care homes, a staff alarm should not incorporate any delay in summoning of the fire and rescue service when the fire alarm system operates, but there may be a delay in the general alarm signal, provided all staff are made aware of the fire alarm;

  • Filtering measures should not be applied to signals from fire alarm systems in residential care homes; instead, the fire and rescue service are to be summoned immediately the fire detection and alarm system operates.

When dealing with filtering measures generally, alarms from heat detectors or sprinkler systems are now included along with manual call points as the type of alarms which should be excluded from filtering.

A further important alteration recognises that routine servicing of a fire detection and alarm system does not constitute a fresh review of the system design, therefore non- compliance with BS 5839 might not be identified during such servicing.


BS 5839 Part 1 – System Maintenance

Detailed maintenance procedures are a key element of BS5839, which are defined as the work of inspection, servicing and repair which is necessary in order to maintain the efficient operation of the installed system.  This ranges from weekly user tests of the system, through to periodic servicing by a specialist company. The Code recommends that the frequency of servicing should be based on a risk assessment but should not exceed once every six months.

The Code sets out the minimum work that should be carried out during servicing, including the examination of false alarm records, to determine whether any action is required to remedy these. Regardless of the servicing interval, the Code defines the work that should be carried out over a twelve-month period, which includes the test operation of all manual call points and functional testing of all detectors (except heat detectors of the frangible type that would necessitate replacement after testing).

BS5839 - Part 1 recognises that routine servicing of a fire detection and alarm system does not constitute a fresh review of the system design, therefore non- compliance with the standard might not be identified during such servicing.



Ensuring the appointment of a quality fire alarm contractor is a fundamental consideration. RiskSTOP standard recommendation is that the system is designed, installed, commissioned and maintained by a company which is approved by an accredited third-party certification scheme, of which the Loss Prevention Certification Board (LPCB) LPS 1014 and the BAFE SP 203 Schemes are examples.



(Following a change in name to the National Fire Chiefs Council (NFCC), references to ‘CFOA’ should now read ‘NFCC’)

Despite a reduction in false alarms from automatic fire detection and alarm systems in recent years, false alarms and unwanted fire signals continue to be a serious concern.

In response, the Chief Fire Officers Association (CFOA) has published Guidance for the Reduction of False Alarms and Unwanted Fire Signals, which replaces the previous CFOA Protocol; this is contained in ATLAS. The aims of this publication, which has been developed by stakeholders representing the fire alarm industry and the Fire and Rescue Services (FRS), are three-fold:

  • To reduce the number of false alarms generated by AFA systems.

  •  To reduce the number of Unwanted Fire Signals (UwFS) sent to FRS.

  • To provide a working framework that offers a sufficient level of flexibility, whilst establishing a structure with sufficient consistency to satisfy the legal and other operating obligations of practitioners.

The stated aim of the guidance should be for all stakeholders to work together to ensure that, ignoring persistent false alarms rather than fixing the problem is not acceptable.

The CFOA guidance provides a “Tool Kit” approach for FRS to formulate their own local strategies and policies, recognising that each FRS must determine which of the tools they wish to employ in accordance with their respective Integrated Risk Management Plans and overall arrangements for managing risk. The tools are summarised in chronological order as follows:

  • Highlighting the problem of unwanted calls and false alarms from AFA systems

  • Prevention of false alarms

  • Confirmation of the cause of alarm before calling the FRS

  • Call handling by the FRS

  • Investigation and follow up of false alarm calls

  • Stakeholder engagement

A fundamental recommendation of the CFOA guidance, endorsed by fire safety professionals, is that organisations undertaking design, installation, commissioning and maintenance of AFA systems should ensure that their work meets the recommendation of the relevant code of practice (normally BS5839) and is suitable for the building, its occupancy and intended use, and is designed to minimise false alarms. It also recommends that designers and installers should, where possible, take advantage of modern technology which is focusing on increasingly intelligent components and systems which contribute to the prevention false alarms.

Not surprisingly, the CFOA guide advocates the use of products and services that have received UKAS accredited third party certification, which for companies that design, install, commission and maintain fire alarm systems include the following:

  • SP201(LPS1014) Scheme available from the Loss Prevention Certification Board (LPCB) – reference

  • SP203 Scheme published by BAFE and available from a number of UKAS accredited certification bodies – reference

Also, CFOA strongly recommends that all fire alarm monitoring organisations should be certificated by a UKAS accredited, or equivalent, third party certification body to the relevant standard for the types of alarm which they monitor. At the time of writing, these bodies comprise:

  • NSI


  • LPCB

In common with the previous CFOA protocol, the latest guide sets out levels of AFA response options applicable to systems which present persistent false alarms. The three principal repose options are as follows:

  • Attendance Level One: is an immediate emergency response, resulting in an initial attendance based on a risk assessment of the firefighting requirements that will be not less than one fire appliance.

  • Attendance Level Two: in the absence of a confirmation call via the 999 system; the FRS will make an attendance based on a risk assessment of the firefighting requirements. The attendance may be made under non-emergency conditions, thereby maintaining the availability of the resources for confirmed emergencies and protecting the public from the risk that arises from fire appliances responding under emergency conditions.

  • Attendance Level Three: no emergency response, until a confirmation of fire is received from the premises via the 999 system or from some other acceptable source. Such confirmation will result in a full or enhanced emergency response, dependent on the information received.

Whilst adopting the ethos of past CFOA guidance, some FRS have introduced blanket policies whereby, unless the alarm is confirmed by a 999 call or by other means, no attendance will be provided to AFA signals from “standard risk” commercial/business premises, either at all times or, in the case of some FRS, during “normal working hours” (the times of “normal working hours” vary between individual FRS).  Some FRS also discriminate between Monday-Friday and Weekends. Such measures in the main do not apply to “sleeping risks” such as hotels, hospitals, care homes, boarding schools, etc.

Details of these policies are the subject of RISCAuthority publication RI11: Report to Insurers – fire and rescue service response to calls originating from automatic fire alarm systems (see below), which includes an appendix summarising the various FRS policies appertaining at the time of publication (2012). The data in this appendix was updated by the publication in 2015 of research conducted by the Fire Industry Association (FIA) which shows an increase in the number of FRS adopting a policy of no attendance for an unconfirmed AFA in “standard risk” commercial/business premises (see below). 


Whist fully appreciating that false alarms from automatic fire detection systems are an immense drain of FRS resources, removal of response outside of working hours, unless the fire is confirmed, totally undermines the protection benefits of such systems, raising serious questions as to the viability of AFA protection going forward. This situation will be kept under review.



In circumstances when an AFA system is encountered, the following information should be obtained and reported on as appropriate:


  • Design criteria – BS 5839 and system category

  • Presence and method of remote signalling


  • Name and accreditation, where applicable, of the installers


  • Extent of routine testing and maintenance regimes and whether BS 5839 compliant


  • History of false alarms and published FRS alarm response policy by reference to the FRS Unwanted Fire Signals Response Policy published by the FIA.

When encountered in the SME environment, systems will have commonly been installed for life safety purposes (typically Category M/L5 – M/L3 with audible signalling only). Such systems are likely to have minimal impact on the property risk and, as such, may not warrant full consideration. However, as the size and complexity of the risk increases, the presence of alarm protection, particularly systems which have been designed to a P1 standard, can become a key underwriting feature on which a correct assessment must be made. Whilst Category P1 will be the normal design standard for property protection systems, the merits of a P2 system should not be ignored, particularly when installed for the specific protection of a hazardous area or process, or a critical business facility. A P2 system can also form a valuable component of a “fire engineered” solution.

When making an assessment of an existing AFA system or raising a risk improvement for a new installation, it is important that full recognition is given to the availability of the FRS and the presence of an effective water supply nearby to the premises, without either of which, the protection value of an AFA is considerably diminished. In this regard, the current trend towards either a zero or limited response by some FRS to AFA signals until confirmed is a major concern. In circumstances where a remotely monitored AFA system is encountered on site in an area where there is a known limited or nil FRS response to unconfirmed signals, the Consultant must ensure that the Policyholder is aware of the FRS policy and the potential reduction in protection.

Risk improvements calling for the installation of a remotely monitored, Category P1 fire detection and alarm system, need to be carefully considered. Except for special risks such as an unattended overnight manufacturing process, risk improvements for full AFA protection should not normally be raised without first considering the installation of sprinklers as a first option and, in any event, would normally only be considered for premises with a combined MD/BI exposure of £10m and over. Prior to considering any risk improvement for an AFA system, it is essential that recognition is taken of the alarm response policy adopted by the relevant FRS and its impact on such a system.

Brief reference is necessary to cases where a risk improvement is sometimes made to connect an audible only AFA into the remote signalling system serving the intruder alarm. Whilst such a risk improvement is well intended, little benefit would be derived from this arrangement where a confirmed FRS protocol applies. It is also important that recognition is given to the quality and maintenance of the fire alarm system in question, allied with the false alarm history, and the fact that for aspects such as the provision of fire-resistant cabling and standby battery supply, the intruder alarm signalling installation is unlikely to be compatible with the requirements of BS 5839.



  1. RC47 – Recommendations for the management of fire detection and alarm systems in the workplace, provides excellent guidance with particular emphasis on the avoidance of false alarms and unwanted fire signals.

  2. FRS Unwanted Fire Signals Response Policy published by the FIA – Unfortunately, this document which was prepared in 2015 has not been updated and may no longer be completely accurate



Notifier by Honeywell has published its “Little Black Book” which, despite the title, is a comprehensive and easy to read guide on fire detection and alarm systems. Whist obviously slanted towards Notifier products and services; it nonetheless provides an excellent source of reference. The publication can be obtained free of charge in hardcopy or electronic format from

The Babour Guide – Fire Detection & Alarm Systems is another useful publication.

For information concerning BS5839 – 6 (domestic systems) reference can be made to the guide produced by Fire Angel Safety Technology. Limited 

bottom of page