BS 5839-1:2025 – What’s New in the UK’s Fire Alarm Standards
On April 30, 2025, the British Standards Institution released the updated BS 5839-1:2025, replacing the 2017 edition. This revision sets out the current best practices for fire alarm system design, installation, commissioning, and maintenance in non-domestic buildings across the UK.
What is BS 5839-1?
BS 5839-1 is the UK’s key standard for fire alarm systems in commercial and other non-residential properties. It is referenced in Approved Document B of the Building Regulations and provides detailed guidance on system categories, components, installation locations, performance, and ongoing maintenance to ensure safety and legal compliance.
Major Updates in the 2025 Version
- Preferred Detectors in Sleeping Areas
Smoke detectors are now the recommended choice over heat detectors in sleeping spaces like hotels, care homes, and student housing to improve early detection. - Expanded Category Coverage
Lift shafts must be included in L4 system coverage. Additionally, detection in low-risk lobby areas is now required depending on system type. - Improved Manual Call Point Placement
Clearer guidance has been introduced to position manual call points in areas regularly used by occupants, improving access and reducing accidental triggers. - Integration of Lockdown Alert Tones
Fire alarm panels can now feature lockdown tones distinct from fire alarm sounds to avoid confusion during emergencies. - Addressing Obstructions on Ceilings
Installers must factor in physical obstacles such as beams or ducts that may block detector coverage, preventing blind spots. - Faster Monitoring and Response
Fire alarm activations must be signaled within 90 seconds and faults reported within three minutes to speed up reactions. - Updated Battery and Cable Specifications
Red-coloured mains cables are mandatory for easy identification. The formula for battery backup capacity has been revised, requiring reassessment of existing systems. - Greater Emphasis on Visual Alarm Devices
There’s increased focus on visual alarms to assist individuals who are deaf or hard of hearing. - Mandatory Zone Plans in Multi-Zone Buildings
Clearly displayed zone plans must be positioned near control panels in buildings with multiple fire alarm zones to aid quick response. - Additional Requirements for Residential Care Premises
Fire alarms in care facilities must now send automatic alerts to central monitoring stations for rapid intervention. - Flexible Servicing Intervals and Detailed Maintenance
The servicing window is now between five and seven months, rather than strictly six. Maintenance must include clock checks, log updates, removal of redundant devices, and accessible control interfaces. Technicians should maintain their professional skills through Continuing Professional Development. - Updated Documentation and Certification
All certificates, logs, and documentation formats have been refreshed. Any system modifications require formal Modification Certificates, with deviations properly recorded.
Why These Changes Are Important
The BS 5839-1:2025 update enhances fire safety by:
- Improving detection speed and reliability, especially in sleeping areas
- Allowing greater flexibility and clarity in system maintenance
- Supporting inclusivity with better visual alarm requirements
- Raising professional standards through updated documentation and training
Staying current with BS 5839-1:2025 is vital for fire safety managers and building owners to ensure compliance and protect occupants effectively.
