A proper fire alarm installation in the UK begins with sound design and adherence to current standards. In practice this means aligning with BS 5839‑1:2025, the British Standard for fire detection and alarm systems in non‑domestic premises. This standard sets out the required steps for planning, selecting devices, placing detectors, specifying zones, securing wiring, and commissioning. For businesses, this stage is critical: a fire alarm system that is poorly designed or installed in breach of standard may not provide reliable detection, may fail inspection, and might invalidate insurance policies.
What is included in a full fire alarm installation in the UK generally covers:
Initial site survey and risk assessment to understand building layout, occupancy, fire risk and escape routes.
Design of system including choice of category (L, M, P) of detection vs manual call points, zones, sounder coverage, detectors etc.
Supplying all required equipment that meets EN 54 or relevant certified device standards.
Routing and installing wiring / cabling which may need fire resistance depending on the building type, with attention to cable layout, support, protection, avoiding interference or hazards.
Installation of control panel(s), manual call points, detectors, sounders (and visual alarm devices where required), interface with other safety systems (e.g. emergency lighting, fire doors), installation of backup power supply.
Commissioning, including testing all devices, ensuring that alarms are audible and visible as needed, ensuring zones work as designed, calibrating detectors, ensuring proper documentation, user handover, system log books and certification.
Commercial fire alarm installation refers to setting up more complex systems for larger or higher‑risk premises such as offices, multi‑storey buildings, hotels, warehouses, or public assembly spaces. These installations usually involve addressable systems or complex zone‑based conventional systems, or even hybrid ones. In such installations the detection devices, sounders, control panels, and alarm zones are carefully planned to ensure every area is covered, escape routes are safe, and the system can identify precisely where an alarm is triggered.
What’s Included
Detailed design based on occupancy, usage, fire risk, building layout, and integration with other building systems.
Specification of zones: where detection zones and alarm zones are needed to allow faster location of the fire and more efficient evacuation.
Installation of addressable detectors or conventional detectors plus manual call points, sounders, visual alarm devices, all mounted and wired per standard.
Interfaces: integrating with emergency lighting, fire doors, HVAC shut‑down, possibly building management systems.
Ensuring adequate audible and visual notification throughout the premises, including for people with disabilities.
Testing and commissioning, with full documentation, as‑fitted drawings, certification, user training.
BS 5839‑1 was updated in 2025, superseding the 2017 edition. It provides the latest guidance on design, installation, testing, certification and ongoing maintenance of fire detection and alarm systems in non‑domestic premises.
Understanding these new requirements is vital for any business commissioning or upgrading a fire alarm installation.
What’s New & What’s Included in Compliance
Updated guidance on detector placement, particularly for sleeping accommodation and areas with risk, ensuring smoke detectors are used where earlier versions allowed heat detectors.
Enhanced requirements for manual call point positioning, ensuring that they are placed in normal circulation paths and reachable locations.
Stronger documentation requirements: as‑fitted drawings, complete commissioning records, detailed specification of cable type, resistance, sound levels etc.
Specification of wiring and cabling with fire resistance, correct support, loop design, short circuit isolation, ensuring that a fault in one area does not disable protection in large parts of the building.
More precise sounder‑level requirements in certain spaces, including sleeping areas, stairwells, high ambient noise, or for people with hearing impairments.
