BS 5839-1:2025 – The Latest UK Fire Alarm Standard Explained
On 30 April 2025, the British Standards Institution released the updated BS 5839-1:2025, replacing the 2017 edition. This update sets out new guidance for the design, installation, commissioning, and maintenance of fire alarm systems in non-domestic buildings across the UK.
What Is BS 5839-1?
BS 5839-1 is the official British Standard covering fire alarm systems in commercial and other non-residential premises. It is referenced in the UK Building Regulations’ Approved Document B and outlines system types, device positioning, performance criteria, and maintenance requirements to safeguard lives and ensure compliance.
Highlights of the 2025 Revision
- Smoke Detectors Preferred in Sleeping Areas
For accommodations like hotels, care homes, and student housing, smoke detectors are now recommended over heat detectors to enable faster fire detection. - Category Updates
Lift shafts are now included in L4 fire alarm systems. Some low-risk lobby areas also require detection depending on the system category. - Manual Call Point Installation
Call points should be installed in areas frequently occupied by people, improving ease of use and reducing false alarms. - Lockdown Alert Integration
Fire alarm panels may include lockdown tones that must be clearly distinguishable from standard fire alarm sounds. - Accounting for Ceiling Obstructions
Installers must consider structural obstructions such as beams or ductwork that could block detector coverage. - Quicker Activation and Fault Reporting
Automatic fire alarms must signal activation within 90 seconds, and faults must be reported within three minutes to accelerate response. - New Battery and Cable Standards
Red mains cabling is now mandatory for identification, and battery backup sizing methods have been revised, requiring reassessment of existing systems. - Emphasis on Visual Alarm Devices
There’s increased focus on VADs to assist those who are deaf or hard of hearing. - Mandatory Zone Plans for Multi-Zone Sites
Zone plans must be clearly displayed near control panels in buildings with multiple fire alarm zones. - Residential Care Fire Alarm Improvements
Systems in residential care premises must automatically notify central monitoring stations for rapid emergency response. - Flexible Servicing Intervals and Maintenance Tasks
Servicing windows have been extended to 5–7 months. Maintenance now includes clock synchronization, log updates, removal of redundant devices, and accessible interfaces. Technicians should maintain Continuing Professional Development (CPD). - Updated Documentation and Certification
All certificates, logs, and documents have been revised. Modification Certificates are required for changes, with any deviations properly recorded.
Why the Update Matters
These changes improve fire safety by:
- Enhancing detection speeds, especially in sleeping areas
- Introducing flexible and clearer maintenance requirements
- Improving inclusivity with better visual alarms
- Strengthening professional standards through updated documentation and training
Fire safety managers and building owners must stay informed about BS 5839-1:2025 to ensure compliance and keep occupants safe.
