BS 5839-1:2025 changes explained
What the new fire alarm standard means for businesses, landlords and care providers in Bradford, Leeds and West Yorkshire, in plain English.
What changed in BS 5839-1:2025
BS 5839-1:2025 replaced the 2017 edition on 30 April 2025. It is the code of practice for designing, installing, commissioning and maintaining fire detection and fire alarm systems in non-domestic buildings in the UK.
Most of the changes tighten up design decisions, paperwork and remote monitoring rather than asking everyone to rip out working systems. The standard is not retrospective, but anything new, extended or substantially altered from now on should follow the 2025 edition. If a fire risk assessor, insurer or the fire and rescue service reviews your premises, this is the edition they will work to.
Below is a plain-English summary of the changes that matter most to building owners and managers in Bradford, Leeds and across West Yorkshire.
The main changes at a glance
Sleeping areas: smoke detection instead of heat
Under the 2017 edition, heat detectors were often used in hotel bedrooms and similar rooms to cut false alarms. The 2025 edition recommends smoke, multi-sensor or CO detection in rooms where people sleep, unless your fire risk assessment gives a clear reason to use heat detection. Smoke detection gives earlier warning of a slow, smouldering fire, which matters most when the person in the room is asleep.
This is not retrospective, so existing bedrooms do not have to be changed straight away. When a system in a hotel, guest house, care home, HMO or student building is replaced or substantially extended, plan for the new recommendation. Modern multi-sensor detectors help keep false alarms down from steam and aerosols.
Stairways and escape routes
For Category L1, L3 and L4 systems, smoke or multi-sensor detection now covers main access and egress stairways as well as escape stairways, corridors and common escape routes. If you are planning an extension or refurbishment, ask your designer to check stairway coverage against the new wording.
Variations and documentation
A variation is any place where a system does not follow the standard. In the 2017 edition only “major” variations had to be recorded. Now every variation should be agreed and written in the system logbook, so the next engineer, assessor or insurer can see what was decided and why.
Some variations are no longer acceptable at all. The two that affect most of our customers are:
The standard also asks the designer to state which category the system is designed to (for example L2 or P1) and to agree it with the purchaser or user. It also asks them to agree whether visual alarm devices (VADs) are included. If your paperwork does not state a category, a 2025 inspection is likely to pick that up.
Manual call points
The old 25 m and 16 m distance figures have gone. The rule now is that nobody should have to travel more than 45 m along their actual route to reach a call point. There is also a mounting height tolerance (+200 mm / −300 mm), and call points should not be placed on stair landings in multi-storey buildings that use phased evacuation.
Alarm receiving centres and false alarms
Where a system is monitored, the ARC should know whether people sleep on site, what type of device has triggered, and whether more than one device has gone off. This helps the fire and rescue service decide how to respond. Panels with an automatic connection to the fire and rescue service should display a “False Alarm Notice”. Reducing unwanted alarms is a theme throughout the standard, and our engineers look at it on every service visit.
Other technical changes
What should you do now?
For most businesses, the right step is to make sure your next service visit is carried out to BS 5839-1:2025. During the visit, check that the logbook, zone plan and variations are up to date. If you are planning a new system, an extension or a change of use (for example converting offices to flats), design it to the 2025 edition from the start.
Salts Fire & Security is BAFE SP203-1 registered for fire alarm design, installation, commissioning and maintenance. We can survey your existing system against BS 5839-1:2025 and give you a written list of anything that needs attention. See our fire alarm services or find us in Bradford, Leeds and across Yorkshire.
Common questions
When did BS 5839-1:2025 come into force?
It was published and took effect on 30 April 2025, when BS 5839-1:2017 was withdrawn.
Do I have to upgrade my existing fire alarm to BS 5839-1:2025?
No. The standard is not retrospective, so a system that met the 2017 edition when installed does not have to be changed straight away. New systems, extensions and substantial alterations should follow the 2025 edition, and servicing should be carried out to it.
Are heat detectors still allowed in bedrooms?
The 2025 edition recommends smoke, multi-sensor or CO detection in sleeping rooms. Heat detection can still be used where the fire risk assessment justifies it, for example where steam would cause frequent false alarms.
What is a variation in a fire alarm system?
A variation is any part of the system that does not follow the recommendations of BS 5839-1. Under the 2025 edition all variations must be agreed and recorded in the logbook, and some, such as having no zone plan, are no longer acceptable.
How far can a person travel to a manual call point?
BS 5839-1:2025 sets a maximum of 45 m along the route a person would actually take, replacing the old 25 m and 16 m figures.
Can Salts check my system against the new standard?
Yes. Our engineers cover Bradford, Leeds and the rest of West Yorkshire and can inspect your system, logbook and zone plan against BS 5839-1:2025 and give you a written report. Call 01274 599888.
Last reviewed 04/11/2026 by the Salts Fire & Security team, Baildon. This is general guidance; your fire risk assessment and the full standard take priority.