BS 5839-1:2025 explained
BS 5839-1:2025 is the current British Standard code of practice for fire detection and fire alarm systems in non-domestic premises. It superseded the 2017 edition.
Reviewed: 20 August 2026
This guidance is general information. The correct fire safety measures depend on the premises, its use, occupants, fire risk assessment and applicable legal duties.
What it covers
BSI describes BS 5839-1:2025 as providing recommendations for design, installation, commissioning and maintenance of fire detection and alarm systems in non-domestic premises. It is a code of practice rather than a rule that a system must be installed in every building.
The 2025 revision
BSI identifies changes including a new section on extensions and modifications, tighter control of certain variations, revised manual call point recommendations and improved guidance for detection in sleeping areas.
Categories and objectives
The standard uses life-safety L categories and property-protection P categories to describe system objectives and extent of automatic detection. The appropriate category should follow from risk, fire strategy or specification.
Historical certificates
Older certificates can legitimately refer to the edition current or specified when the work was done. The edition, scope, variations and subsequent maintenance should be read together.
Frequently asked questions
Is BS 5839-1:2017 still current?
No. BSI lists BS 5839-1:2025 as current and states that it supersedes the 2017 edition.
Does BS 5839-1 decide if a building needs a fire alarm?
No. It is a code of practice for systems where fire detection and alarm provision is required or chosen.
Sources and further reading
For legal duties and technical standards, use the current primary source and professional advice where required.