Certification (BS 5839-1:2025)
Overview
BS 5839-1:2025 requires formal certification at every stage of a fire detection and fire alarm system. Certificates provide evidence of compliance with the standard and form part of the legal fire safety documentation under the Regulatory Reform (Fire Safety) Order 2005 and the Building Regulations.
Certificates must be issued by the organisation responsible for that stage of the work, signed by a competent person. They demonstrate that design, installation, commissioning, acceptance, and any later modifications comply with the standard.
Certificate Types and Responsibilities
| Certificate Type | Purpose | Signed By |
|---|---|---|
| Design Certificate | Confirms that the design meets BS 5839-1 (coverage, category, zoning, detector type, audibility, cause & effect). | Competent designer, consultant, or company responsible for the design. |
| Installation Certificate | Confirms the system was installed in accordance with the design and BS 5839-1 workmanship standards. | The installing contractor or organisation, signed by an authorised representative. |
| Commissioning Certificate | Confirms programming, cause & effect, device testing, battery sizing, and system functionality comply with BS 5839-1. | Competent commissioning organisation/engineer. |
| Acceptance Certificate | Confirms handover of the system, documentation, and user training. | The purchaser or Responsible Person (not the installer). |
| Verification Certificate | Used for independent verification of large or complex systems before handover (Clause 41). | Independent verifier or third-party organisation. |
| Extensions/Modifications Certificate | Confirms alterations or extensions to an existing system comply with BS 5839-1 and do not invalidate prior certification. | The organisation responsible for the modification; others (e.g. original designer) sign if their scope is affected. |
Modification Certificates
When Acceptable
A Modification Certificate (Annex G.7) may be issued where:
- The existing system has valid original certification (design, installation, commissioning).
- The works are alterations or extensions, not a complete new installation.
- The scope of works is clearly defined and limited to the changes made.
- The untouched parts of the system remain compliant.
Examples:
- Adding detectors, call points, or sounders to an existing loop.
- Extending coverage into a new building area.
- Replacing a control panel where devices/wiring are retained.
- Changing cause & effect programming (e.g. evacuation delays).
- Converting a conventional zone to addressable detection.
When NOT Acceptable
A Modification Certificate cannot be used where:
- No original certificates exist.
- The system has been wholly replaced (devices, wiring, or zoning).
- Works are so extensive the system is effectively new.
- Modifications fundamentally alter the design (e.g. re-zoning or changing system category).
Key Clauses (BS 5839-1:2025)
- Clause 38 - Documentation: Certificates are mandatory for each stage.
- Clause 39 - Certification: Each stage must be certified separately, even if the same company performs multiple roles.
- Clause 40 - Handover: Certificates form part of the required documentation at handover.
- Clause 41 - Verification: Large or complex systems may require independent verification.
- Clause 45 & 46 - Extensions and Modifications: Modifications must be certified using the Annex G.7 form; scope and extent of liability must be defined.
- Annex G - Model Certificates: Provides templates for design, installation, commissioning, acceptance, verification, servicing, and modifications.
Practical Guidance
- Certificates should be retained in the logbook for the life of the system (Clause 40, Annex H).
- Always state the scope of responsibility clearly (e.g. “Design of extension only”).
- If original certificates are missing, a Verification Certificate (Clause 41) may be required before issuing new certificates.
- Certificates can be adapted in format, but must include the same information and declarations as Annex G.
- Certificates are signed on behalf of the responsible organisation, unlike BS 7671 electrical certs which require individual signatures.
- The Responsible Person always signs the Acceptance Certificate, not the contractor.
In summary: Certificates under BS 5839-1:2025 provide a complete compliance trail.
- Design → Installation → Commissioning → Acceptance cover new systems.
- Verification applies to large/complex projects.
- Modification Certificates cover alterations or extensions, provided original certification exists and the system is not effectively new.