Fire Alarm Standards Explained: Navigating BS 5839 for Compliance

Whether you’re a facilities manager or compliance lead, you’ll be familiar with BS 5839. The latest update to the fire alarm BS 5839 Part 1 standard came into effect in April 2025 and is a full-scale revision of the British Standard governing the design and implementation of alarm systems in non-domestic buildings.

But what does the new standard mean for your business? Here’s what you need to know about the impact of the new BS 5839 regulations on compliance.

What is BS 5839?

If you’re responsible for a public facility, a commercial building, or a multi-occupancy block, you’ll be familiar with BS 5839. This British Standard covers everything from fire alarm control panels to the positioning of fire detectors.

Together with Building Regulations and The Regulatory Reform (Fire Safety) Order 2005 (FSO), BS 5839 ensures that your fire safety system is correctly designed, installed, and maintained.

Is BS 5839 a legal requirement?

BS 5839 isn’t a standalone statutory requirement. Instead, it’s a code of practice that ensures compliance with the FSO.

FSO tasks a “responsible person” with ensuring that their building is equipped with an adequate fire safety system. BS 5839 provides the blueprint for the design, implementation, and maintenance of fire alarms and detectors.

Failure to comply with its methodology could leave your business legally liable in the event of a fire.

What does BS 5839 cover?

BS 5839 established a code of practice for fire detection and alarm systems installed in non-domestic buildings.

Fire alarm design and planning

In addition to the design of your system, BS 5839 specifies the installation and wiring, including the use of fire-resistant cables for fire safety systems.

• Fire-resistant cables must not share trunking with any other services.
• Cables should be secured with fire-resistant clips and housed in fire-resistant conduit.
• Wiring for different zones should be separated to prevent a single fault from causing the entire system to fail.

Fire alarm maintenance and checks

Under BS 5839, your system should be regularly maintained and inspected. This should include:

• Daily visual checks to ensure the fire alarm panel has no active faults.
• Weekly call point activation of alerts, sounders and connected services.
• 6-monthly servicing by a qualified person to inspect the entire system.
• Annual system check including all sensors and call points.

Read more about Ensuring Fire Alarm Compliance: Installation, Testing & Maintenance.

What’s changed in BS 5839-1:2025?

The 2025 revision introduces key updates in the following areas:

1. Design and installation

BS 5839-1:2025 introduces new design principles. Your fire alarm system must be designed by a competent person who understands the challenges of your building. What’s more, they should oversee testing to ensure the system works as intended.

Other significant changes include:

• Placement of manual call points to cover areas that are routinely occupied.
• Integration of lockdown alarm systems provided they have a distinct alarm sound.
• Tighter rules on detector positioning to avoid obstructions and eliminate dead spots.
• Faster monitoring times within 90 seconds for category L systems.
• All power cables must be coloured red.
• Call points must be clearly labelled to avoid false alarms.

2. Maintenance and testing

While service intervals are still required, the new standard introduces some flexibility. Servicing can now be carried out every 5-7 months while maintaining compliance.

Other updates include:

• Service-specific tasks: Technicians must mark the installation date on batteries and check and correct the control panel clock.
• Interfaced fire systems: Must be accessible and functional, with no hidden panels.
• Outdated equipment: Old devices must be removed to avoid confusion in an emergency.
• Fire zone charts: Must be verified and updated if necessary.

3. Certification and documentation

If you’re designing, installing, or modifying a fire alarm system, you’ll need to use the updated certification templates. These documents reflect the new numbering and terminology, including the use of “fire and rescue service.”

BS 5839-1:2025 introduces a new Section 7, aimed at making it easier to extend and modify an existing system with full compliance. The official Modification Certificate ensures that any changes can be traced and meet the 2025 standard.

Most importantly, any design variations from the new standards must be clearly identified and recorded in the fire alarm logbook to avoid ambiguity.

How can phs Compliance help?

Whatever the changes to BS 5839, your Statutory Inspection obligation remains the same.

For Fire Alarm Testing and Fire Extinguisher Testing undertaken by Britain’s largest operator, contact our team of fully-qualified operatives at phs Compliance for support today.