The newly updated BS 5839-1:2025 standard for fire detection and alarm systems in non-domestic buildings was published on 30th April 2025. The revised standard seeks to redefine how fire detection and alarm systems are installed, design, commissioned, and maintained in ‘non-domestic buildings’ – which include offices, shops, hotels, leisure centres, warehouses, industrial facilities, and public spaces. Here’s what you need to know.
What Is Bs 5839-1:2025?
BS 5839-1:2025 is a code of practice or set of guidelines that provides comprehensive recommendations for fire detection and alarm systems. While it isn’t legally binding and doesn’t mandate the installation of such systems as such, it does support compliance with Building Regulations where fire safety systems are required (e.g. Approved Document B).
This makes the standard an essential knowledge base and reference point for any electrician who works on fire safety systems.
Of course, BS 5839-1 is not a new code of practice, having been first introduced in 1980 and subsequently revised in 2002, 2013, and 2017. Many electricians will already have a working knowledge of its contents.
So, What Has Changed In The 2025 Version Of The Standard?
- Restructured clauses: Clause 4 (general principles and foundational concepts) has been moved to the introduction, and Clause 33 has been merged with Clause 31 for better clarity on the technical and procedural aspects of fire alarm systems pertaining to maintenance and testing.
- New section on extensions and modifications: a brand-new section (Section 7) has been added to the 2025 update giving guidance on how to handle extensions and modifications to existing electrical systems. This helps to mitigate risks arising from incorrect modifications, and ensures that all changes maintain the same level of compliance and safety as the original installation.
- Tighter control of variations: certain deviations from recommendations are now explicitly prohibited to avoid safety risks. This is to encourage stricter adherence to best practices and reduce the risk of fatal fire incidents – in December 2024, the London Fire Brigade reported a three year high of fire incidents in care homes and supported living facilities, with 41 fires reported during the month.
- Improved fire detection in sleeping areas: the new guidelines favour automatic fire detection over heat detectors or sprinkler heads in rooms where people sleep, with strong implications for fire safety systems in hotels and guesthouses. This is one of the major changes of the 2025 standards, with detailed guidance for electricians on how to design, implement, and maintain these systems.
What Next?
The updated BS 5839-1:2025 standards are a vital tool for practising electricians, providing a straightforward framework for delivering safer and more reliable fire detection systems. By aligning the standards more closely with the Building Regulations, the update also makes compliance easier and more streamlined for electricians and their customers. From selecting the right detectors for hotel rooms to installing manual call points in supermarkets, the standard gives you the knowledge you need to align your work with the highest safety standards.
For more information about BS 5839-1:2025 and how our training can support your knowledge and competencies, please contact PTT today by clicking here.
