Understanding Fire Alarm Regulations
Understanding Fire Alarm Regulations for Fire Detection and Alarm Systems
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 advise and guide our customers at all times.
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, including system categories (L, P, M) and zoning requirements. The latest BS 5839-1:2025 introduces tighter controls, stronger emphasis on competent design, and addresses changes following real-life incidents, superseding the 2017 version for new projects from April 2025.
Key Standards Explained
BS 5839-1 (Non-Domestic):
This is the primary code of practice for fire detection and alarm systems in workplaces, schools, hospitals, etc., focusing on Categories (L for Life, P for Property, M for Mixed) and system design for effective alerts and evacuations.
BS 5839-6 (Domestic):
Provides specific guidance for homes, covering alarm grades (e.g., Grade D for mains-powered with battery backup, Grade F for battery-only) and placement, updated in 2019/2020 with new grades like D1/D2, F1/F2.
Introduction to UK Fire Alarm Regulations
Fire alarm regulations are part of the The Regulatory Reform (Fire Safety) Order 2005 (which you can access online for free )
It is recommended that Fire Detection and Alarm Systems are installed and maintained to the latest relevant British Standard which is currently BS 5839-1:2025
Types of Fire Alarms under UK Regulations
There are three main types of Fire Detection and Alarm Systems
Conventional, Addressable and 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 the 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.
Fire Detection and Alarm System Categories
Categories – Define where detectors are located and what areas are protected
These are found in BS 5839-1 (Non-Domestic)
Before any fire protection system can be designed, it is necessary to define the main objectives of the system.This is normally determined by the buildings fire strategy plans and/or the Fire Risk Assessment and should be provided as part of the fire system specification
The coverage within the building by the detection system is described with the following codes:
LD1: Covers all circulation spaces that form part of escape routes plus all rooms in which a fire could start
LD2: Covers all circulation spaces that form part of escape routes plus all rooms and areas that present a high fire risk to occupants
LD3: Covers circulation spaces that form part of the escape routes
Fire Detection and Alarm Grades
Grades – Indicate how the system is powered and controlled
These are found in BS 5839-6 (Domestic):
Fire alarm grades (BS 5839-6) classify system quality from A (highest) to F (lowest), determining the type of equipment and power sources used, primarily for residential (domestic) safety. Common grades include Grade A (central control panel system), Grade D1/D2 (mains-powered with battery backup), and Grade F1/F2 (battery-powered).
| Grade | Description | Typical Application |
| Grade A | Full fire alarm system with separate control and indicating equipment, fire detectors, sounders, and backup power | Commercial buildings, hospitals, and some residential buildings such as Houses of multiple occupation (HMOs) or high-risk dwellings |
| Grade C | Detectors and alarms connected to a common power supply, with control and monitoring functions | Higher-risk single-family homes or shared dwellings |
| Grade D1 | Mains powered alarms with a sealed, tamper-proof backup battery | Standard for most UK new builds under the current building regs |
| Grade D2 | Mains powered alarms with user-replaceable backup batteries | Lower-risk domestic settings or older homes being upgraded |
| Grade F1 | Battery powered alarms with a sealed, tamper-proof battery (typically 10 years) | Suitable for low-risk properties, or where mains wiring is not feasible |
| Grade F2 | Battery powered alarms with user-replaceable batteries | Budget solution or temporary accommodation |
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 Standard (BS 5839-1:2025),
- – Understand the types of fire alarm systems available and how they work
- – Specify which category or grade to use
- – Be competent to design, install and commission the system

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 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.
Correct at time of publishing 29/01/2026. Every effort has been made to provide correct and accurate information. Please refer to the British Standards and the The Regulatory Reform (Fire Safety) Order 2005 for published information.


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