A revised British Standard has raised important questions for shops, restaurants, offices and other workplaces. Here is what responsible persons should review — and why an updated standard does not automatically mean replacing a working fire alarm system.
Fire alarms are often treated as equipment that only needs attention when a fault light appears or an engineer is due to visit. In practice, an effective fire detection and warning arrangement must reflect how the building is used, who occupies it, the fire risks present and the emergency plan. That is why the 2025 revision of BS 5839-1 matters to businesses reviewing their fire precautions in 2026.
What changed in BS 5839-1:2025?
BS 5839-1:2025, published on 30 April 2025, replaced the 2017 edition of the code of practice for fire detection and fire alarm systems in non-domestic premises. It provides technical recommendations for planning, design, installation, commissioning and maintenance. The revision is relevant to premises such as offices, shops, restaurants, warehouses, hotels and many other workplaces.
The updated guidance places greater emphasis on managing modifications to existing systems, clearly defining responsibilities, keeping accurate system documentation and controlling unwanted alarms. It also identifies certain departures from its recommendations that should not be treated as acceptable variations. BSI has highlighted a particular change in approach to automatic detection in rooms used for sleeping, where early warning is especially important.
For a business owner, the practical message is straightforward: understand what the system was designed to do, check that it still suits the premises and make sure the records and maintenance arrangements support safe operation.
Is a commercial fire alarm a legal requirement?
In England and Wales, the Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to take appropriate general fire precautions. Articles 9, 13 and 17 are particularly relevant to fire risk assessment, fire detection and warning, and maintenance. The necessary warning arrangements must be appropriate to the risks; the legislation does not prescribe the same alarm category for every business.
BS 5839-1 is a recognised code of practice, not an Act of Parliament. It informs what suitable provision may look like, but the correct arrangement is determined through a suitable and sufficient fire risk assessment, supported by competent system design where needed. A small, simple premises may have different needs from a busy restaurant, a warehouse with isolated rooms or a mixed-use building with accommodation above.
A separate legal point is sometimes missed: since 1 October 2023, changes made through section 156 of the Building Safety Act 2022 mean responsible persons must record their fire risk assessment in full and record their fire safety arrangements, regardless of employee numbers. The old “five employees” threshold for recording the assessment no longer applies.
Which fire alarm category does your premises need?
Fire alarm categories describe the system’s purpose and the extent of automatic detection. Category M relies on manual initiation. Life-protection categories L1 to L5 provide different approaches to automatic detection, while property-protection categories P1 and P2 address protection of the building or its contents. These are not interchangeable labels, and the most extensive category is not automatically the right specification for every site.
The assessment should consider escape routes, travel distances, inner rooms, areas where a fire could develop unnoticed, occupants who may need additional warning, and the relationship between separate occupancies. In a commercial kitchen, for example, detector type and positioning need particular care to balance prompt detection against avoidable false alarms from cooking activities.
Five practical checks for business owners and managers
1. Check whether the building has changed. A new partition, rear storeroom, mezzanine, office, customer seating area or change in operating hours can alter the detection and warning strategy. A system that was suitable when installed may no longer cover the present risk.
2. Find the design and handover records. Ask for the system category, zone plan, commissioning and servicing certificates, logbook and any relevant cause-and-effect information. These records help a competent engineer understand what should happen when a detector or call point operates, including any interfaces with fire doors, ventilation or other safety systems.
3. Review routine testing and servicing. For a system within the scope of BS 5839-1, weekly user testing is normally recommended, using manual call points in rotation and recording the outcome. Inspection and servicing by a competent person is generally planned at approximately six-month intervals. The actual regime should reflect the system, its risk profile and current technical guidance.
4. Investigate repeated false alarms. A nuisance alarm is not merely an inconvenience: repeated unwanted signals can undermine confidence in the warning system. Record each occurrence, identify likely causes and ask a competent contractor to address detector selection, positioning, contamination or other defects rather than disabling protection.
5. Consider everyone who needs the warning. Staff, customers, visitors, contractors and people with hearing or other impairments may not all receive or respond to the same warning in the same way. Alarm audibility, visual or other warning measures, staffing and evacuation procedures should be assessed together.
Does the 2025 standard mean you must replace your existing system?
No. Publication of a revised British Standard does not, by itself, mean every existing fire alarm must immediately be replaced. The key question is whether the current arrangement remains suitable and sufficient for the premises and whether identified deficiencies are being addressed. Some businesses may only need better records, servicing, detector repositioning or a targeted extension. Others may require more substantial changes because of missing coverage, serious faults, changes in use or incompatible equipment.
Before authorising a full replacement, request a competent review of the existing installation and a clear explanation of what can safely be retained. A fire risk assessment should identify the life-safety need; a competent fire alarm designer or installer should then develop and verify the detailed technical solution.
Example: a takeaway within a multi-occupied building
Consider a small takeaway with a customer counter, commercial kitchen and rear office, located within a building shared with other businesses. The kitchen introduces cooking and extraction hazards, while staff may work in rooms out of sight of the customer area. The assessor would need to consider how a fire is detected, whether occupants can hear the warning, how they escape and whether a fire in one unit could affect adjoining occupancies.
The answer is not simply “fit one detector in every room”. The appropriate detection technology, locations, alarm category, interfaces and any arrangements shared with the landlord or neighbouring occupiers must follow the risk assessment and competent design. In multi-occupied premises, responsible persons must also cooperate and coordinate on relevant fire safety measures.
A sensible next step: review the risk before buying equipment
If you are unsure whether your current alarm provision is adequate, start with the building’s latest fire risk assessment, system records and recent service reports. Check whether outstanding actions have been closed, whether staff know how to raise the alarm and whether any changes to the premises have been assessed. Where documents are missing or the system’s suitability is uncertain, arrange a competent review rather than relying on assumptions.
Commercial fire risk assessments in Manchester and the North West
Grey Knight Solutions Ltd supports businesses, landlords and property managers with site-specific fire risk assessments and practical, prioritised recommendations. We assess the relationship between fire hazards, means of escape, detection and warning, fire safety management and the wider building context — not simply whether a fire alarm panel is present.
Need clarity on your premises? Arrange a commercial fire risk assessment or discuss your existing fire safety arrangements with Grey Knight Solutions Ltd. Call 0161 883 7533 or visit www.greyknightsolutions.com.