BS 5839-1 is the code of practice for the design, installation, commissioning and maintenance of fire alarm systems in non-domestic premises. BSI published a revised edition in 2025, replacing the 2017 edition. Here is what building owners and managers need to know.
Does my existing system need upgrading?
No, not simply because the standard has changed. A system installed and maintained to the 2017 edition does not become non-compliant overnight. However, when you extend or modify a system, the new work should be designed to the 2025 edition, and your fire risk assessment may identify improvements that the new edition helps you make.
The main changes
- Effective date. The 2025 edition took effect on 30 April 2025 and supersedes BS 5839-1:2017.
- Extensions and modifications. A new section sets out what must be checked when a system is altered, so that the parts that are not being changed do not fall out of step with the new work.
- Remote access. New cyber security measures apply where fire alarm panels can be accessed remotely.
- Sleeping accommodation. Automatic fire detection is now preferred in sleeping accommodation.
- Detector siting. Guidance has been improved for voids, stairwells, lobbies and escape routes.
- False alarms. There are new requirements for logging, investigating and acting on false fire signals.
- Handover documents. A cause and effect matrix is required at handover, and missing or incorrect zone plans are now treated as a major non-conformity.
- Variations. Control of variations is stricter, and some deviations are now explicitly not allowed.
- Manual call points. Guidance on where to place them has been simplified.
For full detail, refer to the standard itself or the Fire Industry Association's guide to the changes.
What should you do?
- Ask your maintenance company whether they are working to the 2025 edition.
- If you are planning alterations, make sure the design covers the existing system as well as the new parts.
- If anyone accesses your panel remotely, ask how that access is secured and recorded.
- Check that your zone plan is on display and correct, and that you hold a cause and effect matrix.
- Check that your logbook records every false alarm and what was done about it.
This guide is general information about UK fire safety law and standards, not legal advice for a specific building. If you are unsure what applies to yours, ask us or a qualified adviser.