Fire Detection and Alarm Systems Guide

Fire Detection and Alarm Systems Guide

Fire detection and alarm system regulations can seem complex. If you are a landlord, property manager, facilities manager or developer this guide will help you understand the basics. As fire safety professionals, RES are well versed in the various British Standards and fire alarm regulations, and our aim is to always advise and guide our customers.

Key Standards Explained

The main British Standard for fire alarms is the BS 5839 series, with BS 5839-1:2025 covering non-domestic buildings (commercial, public) and BS 5839-6 for domestic premises, providing guidelines for designing, installing, commissioning, and maintaining effective systems for life and property protection.

BS 5839-1:2025 published in April 2025 (replacing the 2017 edition), is the updated code of practice for designing, installing, commissioning, and maintaining fire detection and alarm systems in non-domestic UK premises. This is the primary code of practice for Grade A fire detection and alarm systems in workplaces, schools, hospitals, etc. focusing on Categories (L for Life, P for Property, M for Manual) and system design for effective alerts and evacuations.

BS 5839-6:2019+A1:2020 is the code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in domestic premises including houses, HMOs, and sheltered housing. It sets out recommendations on the appropriate grade (A, C, D and F) of fire alarm system, the correct siting and selection of fire alarms, and the methods for testing and commissioning systems to ensure they operate as intended.
The standard also details the information that should be provided to the end user, the documentation and certificates that should be issued upon completion, and the ongoing responsibilities for inspection, testing and maintenance

Fire Alarm Grades

Fire alarm grades describe the type and quality of system installed, primarily relating to power supplies, system complexity, and control equipment.
Grades range from A (the highest) to F (the lowest).

Domestic premises typically use Grades D–F, while most commercial and higher-risk premises require Grades A–C.

Grade A: A fully featured fire alarm system incorporating automatic detectors, manual call points, alarm sounders, and a central control and indicating panel. These systems must comply with BS 5839-1 (commercial premises) or BS 5839-6 (domestic premises where applicable) and use components conforming to BS EN 54 standards. Grade A systems are standard for most commercial, industrial, and multi-occupied premises.

Grade C: A system comprising detectors and sounders interconnected to a common power supply, typically mains powered with a standby supply, but without a full control panel.
Grade D1: Mains-powered detectors with a tamper-proof battery backup.
Grade D2: Mains-powered detectors with a user-replaceable battery backup.
Grade F1: Stand-alone battery-powered detectors with sealed, tamper-proof batteries.
Grade F2: Stand-alone battery-powered detectors with user-replaceable batteries.

Important note: The fire alarm grade should be determined (along with the category) by a fire safety specialist (competent person), such as fire engineers, fire risk assessors by way of the premises Fire Risk Assessment or Enforcing Authorities.

Fire Detection and Alarm System Categories

While grades describe the system type, fire alarm categories define the level and purpose
of protection the system provides.

BS 5839 categorises fire alarm systems into M for Manual, L for Life and P for Property system.

Category M – Manual Fire Alarm Systems
Category M systems rely on occupants to raise the alarm manually when a fire is discovered. They typically use manual call points (break-glass units) positioned along escape routes and exits, connected to a building-wide alarm system. Manual systems are often used in low-risk premises, where staff are always present to raise the alarm and in conjunction with automatic detection systems. Smaller premises may use simple alert devices, though most commercial
buildings integrate manual call points into a Grade A system.

Category L – Life Protection Fire Detection Systems
Category L systems are automatic fire detection systems designed to protect life.
They are divided into five levels, offering increasing degrees of coverage.

Category L1: Systems installed throughout all areas of the building, providing the earliest possible warning in for example: sleeping accommodation, complex or large premises and buildings with delayed evacuation strategies.

Category LD1 – Maximum life protection for a domestic property
LD1 alarm systems are installed throughout domestic premises. Detectors are fitted in all areas that form escape routes and in all rooms and other areas, other than those that have a low risk of ignition, such as bathrooms and toilets. The goal is to provide the earliest possible warning for occupants to ensure the preservation of life.

Category L2: Systems installed only in defined parts of the building, including all parts necessary to satisfy the recommendations of the code for a Category L3 system. The additional areas protected, over and above those protected in a Category L3 system, are those in which there is either high likelihood of fire starting or a high risk to life if fire does start. L2 systems are commonly used in HMOs, residential care premises and buildings with higher fire risks.

Category LD2 – Additional life protection for a domestic property
LD2 fire alarm systems require detectors to be installed in circulation areas that form part of the escape routes, and in certain rooms or areas that present a high risk of fire to occupants. This would include a kitchen and a key habitable room in the building.

Category L3: Systems designed to give warning of fire at an early enough stage to enable all occupants other than, possibly those in the room of fire origin, to escape safely, before the escape routes are impassable due to the presence of fire, smoke or toxic gases. To satisfy this objective, fire detectors need to be installed in escape routes and, other than in the case of very short corridors, in all rooms or areas that open onto the escape routes. L3 is one of the most commonly specified categories for commercial buildings.

Category LD3 – Standard life protection for a domestic property
Category LD3 systems feature detectors in all areas that form escape routes from the property. Unlike LD2 systems, LD3 systems do not have to place alarms close to high-risk sources of ignition.

Category L4: Systems installed within those parts of the escape routes comprising circulation areas and circulation spaces, such as corridors and stairways. An L4 system is typically suitable for low-risk premises, single-storey building and offices with simple layouts.

Category L5: Systems in which the protected area(s) and/or the location of detectors is designed to satisfy a specific fire safety objective (other than that of a Category L1, L2, L3 or L4 system). L5 systems are risk-driven and tailored to the findings of the premises fire risk assessment.

Category P – Property Protection Systems
Category P systems are designed to protect property and business continuity, rather than life alone.

Category P1: Systems installed throughout all areas of the building and aim to detect fires at the earliest possible stage, reduce damage and minimise business disruption.

Category P2: Systems installed only in defined parts of the building such as high-risk or high-value areas e.g. plant rooms, storage areas and server rooms

Fire Alarm Specification

The specification of a premises fire alarm system (Grade and Category) typically rests with a fire safety specialist (competent person), such as fire engineers, fire risk assessors by way of the premises Fire Risk Assessment or Enforcing Authorities, with the role of a fire alarm system installation or maintenance specialist being there to make practical and advisory recommendations when either installing or maintaining systems.

The premises Responsible Person should ensure that the system either proposed or already installed satisfies the requirements of current legislation (or the legislation at the time of installation) and the insurer of the property by way of the premises fire risk assessment or seek further advice from a competent person or the relevant enforcing authority

Types of Fire Alarms under UK Regulations

There are three main types of Fire Detection and Alarm Systems:
■ Conventional
■ Addressable
■ Wireless

Conventional – Buildings are divided into wired zones
■ A fire alarm panel is used to identify the zone in the event of an alert ~
■ Suitable for small commercial properties or residential buildings where precise location reporting is not required.

Addressable – Exact location identification is possible from the specific device in the event of an alert due to unique addressing of the field devices
■ A fire alarm panel is used to display the specific location and zone of the alert
■ Suitable for larger and/or higher risk properties such as Schools, Care Homes, Hospitals.
■ Systems are scalable and flexible

Wireless – Exact location identification is possible from the specific device in the event of an alert due to unique addressing of the field devices (as per addressable system)
■ A fire alarm panel is used to display the specific location and zone of the alert (as per addressable system)
■ Uses a secure wireless signal to communicate with the devices and report back to the control panel
■ Suitable for Churches, Listed Buildings, Historic Properties, Commercial, Industrial, Residential
■ Systems are more scalable and flexible

RES can install all of these fire alarm types and we will always advise our customers on which type of system is most suitable and cost effective for your application.

Requirements for Installing Fire Alarms

Under UK regulations, a “competent person” should install your fire alarm system.

■ They should fully understand the latest relevant British Standards (BS 5839-1:2025 an or BS 5839-6:2019+A1:2020)
■ Understand the types of fire alarm systems available and how they work
■ Confirm the system specification of which category and grade to use in the premises
■ Be competent to design, install and commission the system

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BAFE Accreditation Scheme

RES have undertaken as a business to adhere to the BAFE Accreditation Scheme for BAFE SP203-1 Fire Detection and Alarm Systems: Third-party certificated by BSI

BAFE Fire Safety Register – The trusted independent register of quality fire safety organisations for the UK since 1984

This provides our customers the knowledge that we are indeed competent to install fire alarm systems.

Maintenance and Testing of Fire Alarms

As per The Regulatory Reform (Fire Safety) Order 2005, all fire alarm systems should be adequately maintained in order to be effective in alerting occupants in the event of a fire. This means that fire alarms should be in perfect working order at all times.

And BS 5839-1:2025 recommends that fire alarm systems should undergo weekly testing by the responsible person. This is to ensure all components of the system, such as call points, are in working order.

In addition to this, professional fire alarm maintenance should be conducted at least twice a year by a competent person. This allows for a more comprehensive assessment and includes tests that can’t be performed during weekly checks, such as the inspection of control panels, detectors, and sounders.

At RES, our engineers are fully qualified to be able to carry out fire alarm system servicing.

Our Fire Detection & Alarm System Services

■ Design, Installation and Commissioning
■ Servicing and Maintenance
■ Additional Works
■ Fire Alarm System Upgrades
■ Fault Finding and Repairs
■ Regular Checks

Protecting People and Property Since 1985

Dual fire extinguisher and fire alarm system servicing and maintenance

Dual fire extinguisher and fire detection and alarm system servicing and maintenance

Combining your servicing

Combining your fire extinguisher servicing and fire detection and alarm system servicing into one visit can reduce your overall annual servicing costs and minimise disruption to your premises.

RES have a dedicated team of “dual” engineers that can service both types of fire safety equipment at your premises.

If we currently service your fire extinguishers and not your fire detection and alarm system, please get in touch to discuss your requirements. Similarly, if we look after your fire detection and alarm system and would like us to service your fire extinguishers, get in touch!

RES cover the South of England including the counties of Middlesex, Essex, Kent, East Sussex, West Sussex, Surrey, Hampshire, Dorset, Wiltshire, Gloucestershire, Berkshire, Oxfordshire, Buckinghamshire, Hertfordshire including London, North London, Brighton, Portsmouth, Southampton, Winchester, Bristol, and the various towns of Alton, Aldershot, Andover, Basingstoke, Beaconsfield, Bracknell, Cobham, Cirencester, Epsom, Egham, Farnham, Guildford, Henley on Thames, High Wycombe, Maidenhead, Marlow, Newbury, Oxford, Poole, Reading, Slough, St Albans, Staines, Swindon, Watford, Windsor, Woking, Wokingham, Winchester and Worthing.

RES Fire & Security – Services Guide 2026

RES Fire & Security - Services Guide 2026

Our latest services guide provides a simple guide to our services and capabilities for fire and security.

RES Fire & Security Brochure 2026

Our services have been developed and steadily grown from our company’s commitment to a BS EN
ISO 9001 quality management system.

CONTENTS

FIRE
■ FIRE DETECTION AND ALARM SYSTEMS
■ EMERGENCY LIGHTING
■ AOV SMOKE CONTROL AND VENTILATION SYSTEMS
■ EMERGENCY VOICE COMMUNICATION SYSTEMS
■ CALL ASSIST SYSTEMS
■ FIRE EXTINGUISHING SYSTEMS
■ FIRE EXTINGUISHERS
■ FIRE DOORS
■ FIRE STOPPING
■ DRY RISERS
■ FIRE HYDRANTS
■ FIRE SAFETY SIGNAGE
■ FIRE SAFETY TRAINING
■ FIRE PLANS

SECURITY
■ METAL DOORS
■ ACCESS CONTROL SYSTEMS
■ CCTV
■ INTRUDER ALARMS
■ KEY HOLDING & RESPONSE
■ REMOTE MONITORING

INFORMATION
■ ACCREDITATIONS, CERTIFICATIONS & MEMBERSHIPS
■ WEBSITE & SOCIAL MEDIA

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NEW FIRE RISK ASSESSOR COMPETENCY STANDARD PUBLISHED

The British Standards Institute (BSI) has published the long-awaited standard setting out a framework for the assessment of fire risk assessor competency.

BS 8674:2025 Built Environment – Framework for Competence of Individual Fire Risk Assessors 

Designed through industry-wide collaboration to reduce the variability of fire risk assessor qualifications, offer consistency across the sector, and support the professionalisation of fire risk assessors, this new standard will help to drive and improve industry-wide standards.

The publication of this standard sees the government take significant strides towards meeting one of the recommendations made in the Grenfell Tower Inquiry Phase 2 report, namely to “establish a system of mandatory accreditation to certify the competence of fire risk assessors by setting standards for qualification and continuing professional development and such other measures as may be considered necessary or desirable”.

The Advance of Wireless Fire Detection – Part 3

The Advance of Wireless Fire Detection - Part 3

Hochiki Ekho - A New Generation of Hybrid Wireless Fire Detection.

Ekho is a wireless based family of products which can be fully integrated into Hochiki’s renowned ESP intelligent hardwired system. At the core of the system is the wireless Translator module.

It is hard-wired to the fire alarm control panel loop and communicates continuously with the wireless devices. Wireless Expander modules are used to extend the radio mesh network, increasing the reach and capacity of the overall system.

Self-Configuring Mesh Network

The Ekho Expander modules create a self-configuring mesh network, which constantly relays field device signals back to the Translator module.

Each wireless device determines which Expander has the strongest signal path and automatically connects to it. The Expander mesh network guarantees an “always on” connection between the wireless devices and the Translator/fire control panel

Key benefits of the Ekho range

– Patented Wireless technology
– ESP Compatible
– Expandable
– Simple Installation
– Self Configuring Mesh Network
– Hybrid System Capable
– Robust and Secure Communication
– Fully Intelligent

Ekho Devices

A full complement of Hochiki Wireless devices are available such as Wireless Traslator Modules, Optical Sensors, Heat and Multi Sensors, Call Points and Sounders.

Adaptable for a broad range of environments

Castles, Cathedrals, Churches, Museums, Modular Construction, Remote Buildings, Asbestos sites, Temporary structures, Banks, Aesthetically sensitive interiors, Concrete structures, Historic / protected buildings, Prisons, Hotels and Offices

RES delivering Ehko

RES have completed a number of installations using the Ehko technology in a Country Manor House, a local School and a Retail Property.

See our latest Hochiki Ekho Case Study here

Images © Hochiki Europe, LLC

The Advance of Wireless Fire Detection – Part 2

The Advance of Wireless Fire Detection - Part 2

The EMS FireCell Solution

EMS FireCell is a “comprehensive analogue addressable fire detection solution with a set of features that make it one of the most advanced fire detection systems available – all without the need for cable.”

EMS has a number wireless / hybrid solutions available that can be used for almost any application.

All solutions are full EN54-25 third party approved products.

Fully Scalable

EMS FireCell is fully scalable from standalone smaller single loop systems through to multi building networks.

It’s “Hub” and “Cluster” infrastructure enables Firecell to be used as a 100% wireless system or as part of a hybrid system.

Control Panel

At the heart of the EMS FireCell Solution is the Taktis Control Panel which features a 7” colour touch screen which provides a powerful yet easy to understand interface.

The Taktis Control Panel enables complex configurations to be setup as well as diagnostic functions to be performed.

Taktis Fire Control panels can be upgraded from 2 to 8 loops, accommodating 126 FireCell wireless devices.

Additional surface mounted repeater panels are also available which can be added around your premises.

Other EMS Fire Control panels are also available in the FireCell range, such as the Syncro AS Control Panel.

Wireless Devices

A complete range EMS Wireless devices are available to complement the solution such as wireless Smoke Detectors, Heat Detectors, Sounders, Beacons, Call Points, Door Controllers, Radio Hubs and Repeater Panels.

The EMS FireCell Solution is ideal for all customer applications, offering flexibility, reliability – all at a competitive price point.

RES Wireless Fire Detection and Alarm Installations

RES have now successfully installed a number of EMS FireCell solutions using the Syncro AS Panel at various customer sites such as at a Health Clinic and a Residential Apartment block.

Please see our case studies for delivered EMS FireCell Installs:
Wireless Fire Detection and Alarm System for Residential Property

Wireless System for Prestigious London Apartments

The Advance of Wireless Fire Detection – Part 1

The Advance of Wireless Fire Detection

RES provide comprehensive Fire Detection and Alarm System installation and maintenance services to our customers, and as part of this service we continually strive to offer the latest technology and products to our customers.

Our engineers undertake regular training, either in house or via our suppliers/manufacturers on the technological advancements such as the latest wireless fire detection and alarm equipment available.

In a series of three articles, we will look at three powerful Wireless Fire Detection solutions on offer that we can employ for customer installations.

Wireless Fire Detection and Alarm Systems
There are a number of solutions available, however the three most reliable and adaptable systems we offer are:
EMS FireCell

EMS – FireCell
A comprehensive analogue addressable fire detection solution providing one of the most advanced fire detection systems available – all without the need for cable.
http://emsgroup.co.uk/

Hochiki Ekho

Hochiki – Ekho
A new generation of Hybrid Wireless Fire Detection.
https://www.hochikieurope.com/product/ekho-hybrid-wireless

Hyfire Taurus

HYFIRE – Taurus
The newest, incredibly powerful and easy to configure EN54-25 wireless system on the market today.
https://hyfirewireless.com/

Why the difference in wireless solutions?

RES are focused on keeping our engineers informed and trained on the latest solutions available today. As a result, we recognise that certain solutions may benefit customers if different ways, the main reasons being:

  1. The existing Fire detection and alarm system may have the capability and capacity to be extended upon, therefore a suitable solution wireless solution that can be linked to the existing protocol can be used.
  2. Each wireless system has its own features and specifications, ranging from differing signal technology, the style and size of the wireless units and the capacity of devices. The system recommended by RES would depend on the specific requirements of the customers premises.
Wireless Fire Detection and Alarm Systems

The Main Benefits of Wireless Fire Detection

  • – Eliminate the need for complex cable networks
  • – Quick and easy installation with minimal disruption
  • – Future Expandability and Greater Flexibility
  • – Can be used to extend an existing system

Let’s look firstly at the Hyfire - Taurus Solution

hyfire taurus wireless fire detection and alarm system

Designed and built around the latest standards, Taurus benefits from Hyfire’s consolidated experience in wireless fire protection.

hyfire taurus wireless fire detection and alarm system

This highly flexible solution is suited to Commercial Properties, Residential Buildings, Highrise Buildings, Healthcare and Education, Hospitality and Catering Facilities, Public and Government Buildings, Schools and Universities, Historic and Landmark Buildings and Temporary Event Sites.

“Taurus ensures unprecedented fire detection performance, application scale and superior reliability. The Taurus wireless platform can easily answer the needs of both small-medium or large sites”

Hyfire’s control panel connects to Taurus translator devices which in turn communicate with up to 128 Taurus wireless devices per each translator. The system is energy efficient and environmentally friendly due to it’s innovative electrical design, ensuring battery management is optimised, giving 10 year battery life on inputs (detectors and call points) and 5 years on outputs (sounders, VADs).

hyfire taurus wireless fire detection and alarm system

The design of your system is undertaken in Hyfire’s innovative TauREX software, which allows the drag and drop of devices onto your imported floor plan. This process reduces on site install times and provides a complete system overview for easy maintenance.

hyfire taurus wireless fire detection and alarm system

The Taurus solution uses Hyfire’s Pathfinder technology, which delivers the perfect balance of range and confidence.

RES can see multiple customer applications for this solution for Hybrid installations, where it is more cost effective and practical to install wireless devices across a site.

RES recently completed an installation using the Hyfire Taurus solution – click here to read more.

The Importance of Regular Fire Safety Inspections and Maintenance – October 2021

The Importance of Regular Fire Safety Inspections and Maintenance

It is vitally important to regularly inspect and maintain your buildings fire safety equipment. As a business owner, you are responsible for the safety of your building, employees and visitors. This includes the provision of adequate fire safety equipment and systems throughout the building. With more and more businesses returning to the office, it is essential to check that your fire safety equipment is regularly inspected.

Fire Extinguishers­

Fire Extinguishers need to be inspected and maintained by a competent person once a year in accordance with BS 5306. During these thorough checks your extinguisher is serviced and any necessary repairs are carried out or a replacement is recommended. A basic service would include checking it is in date, hasn’t been tampered with, is in good working order, is the correct weight and pressure and has the correct signage and positioning.

BS5306 recommends that fire extinguishers are tested by discharge every five years (water foam and powder) and refilled or replaced, and every ten years (CO2).  CO2 bottles are hydraulically tested at the ten year point, or the extinguisher is replaced.


It is also a requirement to keep a record of all servicing, maintenance and inspections of fire extinguishers.


Outside of the annual inspections, the responsible person for the premises should ensure that a visual inspection is carried out on all fire extinguishers monthly as follows;

    • – Check that the extinguishers are in the correct location
    • – Check that the anti-tamper seals are not missing
    • – Check the pressure gauge is in the green section
    • – Check for any damage to the extinguishers
    • – Confirm the operating instructions are legible
    • – Ensure the extinguishers not obstructed and are visible

RES extinguisher engineers are BAFE accredited (BAFE BS 5306 Part 3- Portable Extinguisher Maintenance).

Fire Alarms

British Standard: BS 5839 recommends any installed fire alarm system in your premises be maintained by a competent person at least twice a year. This includes detectors, call points and panels. A competent person is someone who has sufficient technical knowledge, understands the different types of fire alarms and how they work, is familiar with the makes and models, and has a good understanding of the legal requirements including the Regulatory Reform (Fire Safety) Order 2005 (RRO/FSO) and the BS 5839.

Routine fire alarm maintenance checks should be carried out by a competent person and include the following:

    • – Control panels
    • – Devices (sensors and detectors)
    • – Call points
    • – Voice alarms
    • – Batteries
    • – Reporting (Log book entry is a requirement)

RES provide fire alarm regular checks, servicing and maintenance. RES fire alarm engineers are BAFE accredited to BAFE SP203 – Fire Detection and Alarm System Modular Scheme SP203 – Part 1.

Emergency Lighting

Emergency Lighting is covered by BS EN 50172 / BS 5266-8 which provides guidance on the minimum level of testing dependant on the type of site you operate. Your responsible person should oversee the appropriate schedule.

Testing is as follows:


Monthly – Test all emergency lighting systems and ensure all luminaries and signs illuminate and are clean and present. A quick flick test is adequate.


Annually – To check that the lights remain illuminated for their full rated duration.


For safety reasons, the standards advise that the emergency lighting testing should be carried out at times of least risk to the buildings occupants or if possible, when the premises are unoccupied or in unoccupied portions of those premises.


RES provide Emergency Lighting Inspection and Testing, Fault Finding, Repairs and Regular Checks

RES fire alarm engineers are BAFE accredited to BAFE SP203 – Fire Detection and Alarm System Modular Scheme SP203 – Part 1.

Passive Fire Protection – Fire Doors

It is good practice to regularly inspect that your fire doors function correctly and that it will perform to its designed standard. Fire doors where traffic is high are more likely to be damaged and should be checked once a week/month (dependent on usage) by the responsible person for the property.


Periodic checks should be carried out every six months. Article 17 of the Regulatory Reform (Fire Safety) Order 2005 (RRO/FSO) makes it a legal requirement to ensure that fire resisting doors and escape doors are correctly installed and adequately maintained in order for them to be fit for purpose.


RES passive engineers are FIRAS Certified for Fire Door Maintenance.

Passive Fire Protection – Fire Stopping

Fire protection measures can be degraded over time and it is the legal responsibility of the Responsible Person that the fire protection be adequately maintained. It is the responsibility of the responsible person to ensure that regular inspection takes place. Fire stopping is the compartmentation of a building bounded by fire resisting elements such as walls, floors and ceilings. Fire resisting elements are used around cables, pipes and ventilation systems.


We recommend your fire stopping is inspected every six months.

Smoke Control / Automatic Opening Vents (AOVs)

Smoke vents have moving parts such as struts, hinges, pistons and actuators which remain stationary for long periods of time. As a result these systems can be prone to failure or fault. These systems should be regularly checked and subject to two maintenance visits per year to ensure they operate correctly.


RES undertake the servicing and maintenance of Smoke Control / Automatic Opening Vents (AOVs).

Dry Risers

BS 9990 requires that Dry Riser systems to undergo an annual static pressure test and inspection and a six monthly visual inspection, by a competent person. This ensures that the Dry riser system is maintained and functioning correctly for the fire brigade at all times.


RES can undertake dry riser servicing, testing and maintenance.

Fire Hydrants

BS 9990 requires that private fire hydrants to undergo an annual test and inspection and a six monthly inspection by a competent person to ensure the hydrant remains ready and in a working condition for brigade use. The Responsible Person should make periodical inspections of all Hydrants on a weekly and or a monthly basis.


Contact RES for ALL your Servicing, Testing and Maintenance needs.

This article is for general guidance only, please get in touch if you need assistance

Fire Alarm systems for Domestic Premises – 4th August 2021

Fire Alarm systems for Domestic Premises

Domestic fire detection and alarm system standards are outlined in the BS 5839-6:2019, as amended 2020 Code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems for domestic properties.

In this edition there have been some changes to the “Grades” of systems from the previous edition.

The type of domestic premises covered by this British Standard are:

A) designed to accommodate a single family;

B) houses in multiple occupation comprising a number of self‑contained units, each designed to accommodate a single person or family;

C) sheltered housing, including both the dwelling units and the common areas;

D) supported housing.

The recommendations within the standard apply to both new and existing domestic premises with the types of domestic property’s covered include:

– Bungalows,

– Multi-storey houses,

– Individual flats,

– Individual maisonettes,

– Mobile homes,

– Individual sheltered accommodation as well as their common parts,

– Houses in multiple occupation (HMOs),

– Certain NHS housing in the community,

– Mansions,

– Shared houses,

– Houses divided into several self-contained single-family dwelling units.

It also applies to premises used for self-catering holidays if occupied by not more than ten persons, and premises with short-term paying guests in the home of a resident operator with not more than eight guests.

It is limited to premises in which guest accommodation is not located below a ground floor or above a first floor, and in which no storey is greater than 200 m2 in area. For larger premises, the recommendations of BS 5839‑1 apply.

This standard does not to the following property’s:

– Hostels,

– Caravans or boats (other than permanently moored boats used solely as residential premises),

– To the communal parts of blocks of flats or maisonettes.

It does not apply to any premises used for purposes other than as domestic premises (e.g. small shops, factories or similar premises used solely as places of work).

This British Standard breaks the fire alarm and warning systems down into 8 “Grades”.


System grade relates to the engineering aspects of the fire detection and fire alarm system. Higher grades of system tend to provide a greater level of control and monitoring of the system, or greater reliability and availability to perform correctly in the event of fire. The grade of system that needs to be installed depends on the nature of the premises, the level of fire risk and the characteristics of the likely occupants.


Grade A

  • – This system is designed and installed in the main according to the recommendations of BS 5839‑1:2017, (Code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems for non domestic properties). The detectors, sounders and the central control and indicating equipment with a back-up power supply conform to British Standards BS EN 54-2 and BS EN 54‑4.

Grade B

  • – Not currently defined

Grade C

  • – A system of fire detectors and alarm sounders (which may be combined in the form of smoke alarms) connected to a common power supply, comprising the normal mains and a standby supply, with central control equipment.

Grade D1

  • – A system of one or more mains powered detectors, each with a tamper‑proof standby supply consisting of a battery or batteries

Grade D2

  • – A system of one or more mains-powered detectors, each with an integral standby supply consisting of a user‑replaceable battery or batteries.

Grade E

  • – Not currently defined

Grade F1

  • – A system of one or more battery-powered detectors powered by a tamper‑proof primary battery or batteries

Grade F2

  • – A system of one or more battery-powered detectors powered by a user‑replaceable primary battery or batteries.

In the case of Grade D and Grade F systems, where more than one smoke or heat alarm is installed, these normally need to be interlinked.


Levels of Protection/Categories of System

There are three categories for domestic fire detection and fire alarm systems these categories  outline where the detectors/sounders should be installed and level of protection given, the “LD” indicates that the fire detection and fire alarm system is intended for the protection of life.
All domestic premises need to be provided with an appropriate fire detection and fire alarm system, for full coverage a Category LD1 is installed, such a system gives the earliest practicable warning of fire to occupants, wherever ignition occurs.

However, a good level of protection can normally be obtained from a Category LD2 system, in which detection is only provided at points where the fire risk is high or where combustion products would present a significant hazard to life. A Category LD2 system might, for instance, have detectors only in the circulation areas of premises, the living room and the kitchen; other areas might be left without detector coverage. The areas protected by a Category LD2 system include escape routes, i.e. those areas that would be protected by a Category LD3 system.

A Category LD3 system is intended only to protect circulation areas that would be used as escape routes.


Category LD1

  • – A system installed throughout the premises, incorporating detectors in all circulation areas that form part of the escape routes from the premises and in all rooms and areas other than those with negligible sources of ignition, such as toilets, bathrooms and shower rooms.

So detectors/sounders are typically installed in Hallways, Landings, Living Rooms, Kitchens, Bedrooms, Airing cupboards/Meter cupboards etc


Category LD2

  • – A system incorporating detectors in all circulation areas that form part of the escape routes from the premises and also in all specified rooms or areas that present a high fire risk to occupants, including any kitchen etc.

So detectors/sounders are typically installed in Hallways, Landings, Kitchens etc


Category LD3

  • – A system incorporating detectors in all circulation areas that form part of the escape routes from the premises.

So detectors/sounders are typically installed in Hallways, Landings etc


This article is intended as a summary guide and is not a substitute for the full Code of Practice of BS 5839 Part 6: 2019, A1:2020. More information can be accessed here:

You can buy the full BS 5839-6 online from the BSI Shop

Building Regulations are available for free from gov.uk

Components of a Fire Detection and Alarm System

Components of a Fire Detection and Alarm System

There are a variety of components that form a fire alarm system – the requirements of fire alarm system are subject to the Regulatory Reform (Fire Safety) Order 2005 and the design and installation of fire alarm systems is subject to British Standard BS 5839-1:2017.

Control Panels

Control panels continuously manage and monitor the fire alarm device circuits and provide power to these circuits. They provide indication of fire alerts, faults and location. Control panels enable the configuration, testing, disablement and triggering of fire alarm signals and devices. Control Panels are usually located in a low fire risk area such as an entrance / exit lobby and should be accompanied by a zone chart.

Smoke Detectors

Ionization Smoke Detectors

Ionization chamber smoke detectors detect smoke by the reduction it causes in the current that flows between electrodes in an ionization chamber within the detector.

Optical Smoke Detectors

Optical smoke detectors detect smoke by means of the light scatter that results from the presence of a small light source within the detector.

Optical Smoke Beam Detectors

Optical beam detectors operate by detecting the obscuration of the light source that occurs in the presence of smoke.

Combustion Gas Detectors

Combustion gas detectors are point-type detectors that respond to one (or more) of the gases produced by a fire. For example, carbon monoxide is produced when incomplete combustion occurs as a result of restriction of the amount of oxygen available to support the combustion process.

Flame Detectors

Flame detectors detect the infrared and/or ultraviolet radiation that is emitted by flame. Both types use radiation-sensitive cells that “see” the fire either directly or through built-in lenses or reflectors.

Heat Detectors

Heat detectors may take the form of either point type detectors or line type detectors. The detection system may be designed to respond when a fixed temperature is reached. The heat detector may also include a sensor that responds to the rate of rise of temperature. In this case, the detector responds when either the temperature rises at more than a certain rate, or when the fixed temperature is reached.

Multi Sensor Detectors

In a fire detection and alarm system incorporating multi-sensor detectors, each multi-sensor fire detector contains more than one sensor, each of which responds to a different physical and/or chemical characteristic of fire. For example, with a heat and optical multi-sensor detector the optical sensor might be disabled during the day. If this is the case, it is vital that the detectors are spaced for the least sensitive sensor, in this case, heat.

Manual Call Points

Manual call points or Break Glass call points are a key component of a fire detection and fire alarm system which is used for the manual initiation of an alarm. Manual call points should be sited where they can be easily seen next to premises exit doors but not where they are likely to be exposed to accidental damage. It is recommended that they should be fitted with protective covers to reduce the likelihood of a false activation.

Alarm Sounders

Fire alarm sounders are an audible fire alarm device such as a Bell, Dome Bell, Sirens Solid Sate Sounder and Horn and operate throughout the building to indicate the need for evacuation of the entire building. Traditionally, a sound pressure level of 65 dB(A) has been regarded as the minimum acceptable sound pressure level for fire alarm signals or 75 dB(A) in sleeping accommodation. Also the fire alarm sound level should be a further 10 dB(A) above any ambient noises that may be present in a premises.

Power Supply The power supply for the fire detection and fire alarm system is normally derived from the low voltage mains supply in the building. The mains supply needs to be reliable and capable of supplying the largest load that can be placed on it under normal, fire and fault conditions. The mains supply needs to be backed up by a standby supply that is able to support the system while the fault in the mains supply is corrected.

Regular Testing

It is vital that a regular weekly and monthly test to be carried out to ensure that there has not been any major failure of the entire system, or a significant part of the system. For full guidelines please refer to BS 5839-1:2017 Fire detection and fire alarm systems for buildings. Code of practice for design, installation, commissioning and maintenance of systems in non-domestic premises

Weekly tests:

– A manual call point should be operated during working hours (as the purpose of the test is to familiarise and ensure the occupants of a premises can hear the alarm), at approximately the same time each week.

– A different manual call point should be used each time.

– Voice alarm systems should be tested in accordance with BS5839 Part 8Fire detection and fire alarm systems for buildings. Code of practice for the design, installation, commissioning and maintenance of voice alarm systems

Monthly tests:

– Any automatically started generator used for the fire detection and fire alarm system should be tested

– Any vented batteries used as a standby power supply for the fire detection and fire alarm system inspected

Inspection and Servicing

Fire alarm systems need to be inspected and serviced every Six Months by a competent person. Due to the specialist nature of the work, fire alarm inspections are usually contracted out to a fire alarm service organization such as RES, whose competence can be assured via third-party certification and accreditation.

RES are accredited to British Standard Institute BSI EN ISO 9000, are a BSI Kitemark Licenced Fire Alarm Installer, and have BAFE Accreditation for Fire Detection and Alarm System Modular Scheme SP203 – Part 1. RES are also members of The British Fire Consortium, Fire Industry Association, The Fire Protection Association.