BS 5839-1:2025 Now in Effect – What Duty Holders Need to Know

Overview

The revised British Standard BS 5839-1:2025 – governing the design, installation, commissioning, and maintenance of fire detection and fire alarm systems in non-domestic (commercial) premises – came into immediate effect on 29th April 2025.

This update has significant implications for Responsible Persons, Duty Holders, and Accountable Persons operating under fire safety legislation across the UK. There is no transition period. All relevant fire alarm systems must now comply with the revised standard.

Who Needs to Take Action?

If you are responsible for the safety of people and premises in a commercial setting, this update applies to you under:

• The Regulatory Reform (Fire Safety) Order 2005 (England and Wales)
• The Fire (Scotland) Act 2005
• The Fire Safety Regulations (Northern Ireland) 2010

Important: BS 5839-1:2025 does not apply to residential properties such as houses, flats, apartments or HMOs.

Summary of Key Changes

Servicing and Maintenance

• Servicing intervals remain every 6 months, but with a permitted flexibility window between 5–7 months.
• Engineers must check and correct the fire alarm control panel's time settings at each visit.
• Redundant components, including detectors, call points or wiring, must be completely removed, not simply disconnected.
• Interfaces (e.g. for lift control) must be fully accessible for servicing.
• All variations from BS 5839-1 must be clearly documented in the fire alarm logbook.
• Servicing must be undertaken by engineers with up-to-date CPD records.

System Design and Installation

• Mains supply cables must now be coloured red for identification.
• L4 systems must include smoke detection at the top of lift shafts.
• L2 systems must provide detection in rooms presenting a sleeping risk.
• Smoke detection is now required in some low-risk lobbies, such as toilet lobbies, depending on the system.
• Lock-down alarms may now be integrated into the fire alarm system, provided they use a distinct tone.
• Revised guidance is available for battery calculations and the placement of detectors near obstructions (e.g. beams and ducts).

Certification and Documentation

• Certificates must reference the new BS 5839-1:2025 paragraph numbers, even where requirements are unchanged.
• Updated model certificates now form part of the standard.
• Certain elements, including zone chart provision and signal monitoring in care environments, can no longer be recorded as “variations"

New Notification Requirement

• A notice must now be displayed on fire alarm control panels confirming automatic connection to the Fire and Rescue Service – this helps manage occupant expectations regarding false alarms.

Your Legal Obligations

As a duty holder, your responsibilities now include:

• Reviewing and updating your fire risk assessments.
• Ensuring all servicing contractors meet the revised requirements.
• Verifying the competence and CPD status of all engineers working on fire alarm systems.
• Updating all certification, documentation, and logbooks.
• Communicating changes and procedures to relevant building users and stakeholders.

Failure to comply with these requirements could result in enforcement action, formal notices, or prosecution.