**BS 5839** is the British Standard that sets out best practice recommendations for the **design, installation, commissioning, and maintenance of fire detection and alarm systems**. It plays a vital role in achieving compliance with UK fire safety legislation, particularly in non-domestic buildings such as offices, schools, healthcare facilities, and commercial premises.

BS 5839 is split into two major parts:

* **BS 5839-1** → Applies to fire detection and alarm systems in **non-domestic premises**.

This page focuses on the updated **BS 5839-1:2025** edition, which replaces the 2017 version.

Compliance with **BS 5839-1:2025** helps to:

* Improve **life safety** by enabling early warning and effective evacuation.

While it is not a legal document in itself, BS 5839-1 is widely used to demonstrate compliance with statutory fire safety duties.

* **Clause 4** has been moved into the **Introduction**.

* Certain departures from recommendations are now clearly stated as **unacceptable** in Clause 6. For example, omitting a zone plan in multi-zone buildings is not permitted.

* Siting rules have been simplified. Manual call points must be no more than **45m travel distance**, or **30m if the layout is uncertain**.

* The standard now advises against using heat detectors in sleeping rooms, recommending faster-reacting alternatives instead.

* **Category M** → Manual systems without automatic detection.

Each category outlines specific detection coverage and design principles.

* **Cabling** → Must be fire-resistant and installed using appropriate support systems.

* **Weekly Testing** → Test a manual call point each week.

Failure to comply with BS 5839-1:2025 can result in:

* **Increased safety risk** due to ineffective alarm coverage.

**BS 5839-1:2025** reflects modern best practices and addresses lessons learned from fire incidents. Compliance supports:

✅ Safer buildings and occupants.

Whether you're designing, installing, or maintaining a fire alarm system, applying the updated BS 5839-1 is essential to uphold safety, legal duties, and system performance.