The latest update to British Standard BS 5839-1 comes into effect today, 30th April 2025, superseding the 2017 edition immediately. Initially scheduled for 29th April, these changes are designed to enhance the performance, clarity, and inclusivity of fire detection and alarm systems in non-domestic properties.
The BS 5839-1:2025 revision was brought forward by the FSH/12/1 technical committee, with a strong focus on safety improvements following tragic fatal fire incidents. If you're a building owner, facilities manager, or fire safety professional, it’s essential to understand the impact of these updates on your fire alarm system design, installation, and ongoing maintenance.
BS 5839-1 is the British Standard that provides guidance on the design, installation, commissioning, and maintenance of fire detection and fire alarm systems in non-domestic premises. This includes commercial buildings, public facilities, and multi-occupancy residential blocks. The standard is used by fire safety professionals, engineers, and building managers to ensure that systems are fit for purpose, reliable, and legally compliant.
Covering everything from the positioning of smoke detectors and manual call points to wiring and system monitoring, BS 5839-1 plays a key role in safeguarding buildings and occupants across the UK.
FSH/12 is a technical committee under the British Standards Institution (BSI), tasked with developing and maintaining standards for fire detection and alarm systems. Operating under the direction of BSI’s Standards Policy and Strategy Committee, FSH/12 brings together experts from industry, government, and academia to ensure the standards reflect the latest technology, regulatory needs, and lessons learned from real-world fire events. Their work directly influences how systems should be designed, installed, and maintained across the UK.
This 2025 edition introduces a number of structural and practical updates across three key areas:
Detection in New Areas: L4 systems now require detection at the top of lift shafts; L2 systems now account for sleeping risk in addition to risk-assessed rooms.
Lockdown Alarms: These can now be integrated into fire alarm systems but the tone must be distinct from fire alarm tones.
Ceiling Obstructions: Clarified guidance on how to handle obstructions like ductwork or closely spaced beams to avoid any potential interference with fire alarm and detection systems.
Monitoring Times: In Category L systems, signal monitoring must occur within 90 seconds, with faults recognised within 3 minutes.
Battery Calculations: The formula for battery backup sizing has been updated to offer additional clarity to end users.
Prohibited Variations: Items like zone charts and remote monitoring in care homes can no longer be treated as variations.
New Panel Notice: In an attempt to help reduce false fire alarms, fire alarm panels must now display a new label:
“FALSE ALARM NOTICE: This fire alarm has an active connection to the fire and rescue service”
Recording Variations: All variations from the standard must be logged in the site’s fire alarm logbook.
Service Intervals: Still required every 6 months, but there's new flexibility, regular services can now occur every 5 to 7 months without being non-compliant.
Clock Synchronisation: The control panel clock must be checked and adjusted at every service.
Zone Charts: These must be verified during every maintenance visit to ensure they are up to date and correct.
Removal of Redundant Equipment: Old detection devices, call points, and interfaces must be removed if no longer in use to avoid any potential confusion in an emergency.
Interface Accessibility: Interfaces must be fully accessible, hidden panels are no longer acceptable.
In the UK, non-domestic properties are buildings not used solely as private dwelling. This includes offices, shops, schools, factories, care homes, and mixed-use premises. They’re subject to specific regulations like the Fire Safety Order 2005, requiring clear fire safety responsibilities.
These changes are not just administrative, they carry significant implications for compliance and safety. From better detection in vulnerable settings to clearer rules on system alterations, BS 5839-1:2025 aims to create faster, more reliable responses to fire, while improving inclusivity and understanding for users of all abilities.
For building owners, responsible persons, and service providers, this update is a call to action. Ensuring your fire alarm systems are designed, installed, and maintained to the latest standard is essential in order to meet legal requirements and also to improve protection of your building portfolio.
At Ventro, we’re ready to help you assess, review, and upgrade your fire detection and alarm systems in line with BS5839-1:2025. Whether you manage commercial premises, healthcare environments, or residential care premises, our expert teams ensure compliance and best practice across all of your facilities.
Get in touch with Ventro today to book your system review and ensure your fire detection and alarm systems are compliant with BS5839-1 2025.