Fire Alarms During Refurbishment and Phased Occupation
A building under refurbishment is a moving target. Part of it may be a live construction site, part still occupied, and the whole picture changes week to week — while the fire detection and warning that suited the finished building may not suit any of this. The risk is that protection for the people still using the building slips through the cracks of a busy project. Keeping it current, with interim measures where needed, is the real task. This guide covers how it is managed and what to check.
The central point is that protection must keep pace with a changing building, so occupied areas always have appropriate detection and warning while works go on.
Who this is for
This is for competent fire alarm engineers working on buildings being refurbished or occupied in phases. The experience level assumed is competent engineer. Use it for the principles; what protection and interim measures are needed comes from the fire risk assessment for the works — kept under review — coordinated with BS 5839-1 for the permanent system and the relevant guidance for construction and occupied premises.
A building in flux
While a building is refurbished it may be partly occupied, partly a construction site, and changing continually, so the detection and warning that suited the finished building may not suit the works in progress. Protection has to keep pace with that moving situation, including any interim measures for the areas still in use. This is not a static design applied once, but something reviewed as the building changes. How it is managed comes from the fire risk assessment for the works, which should be kept under review, coordinated with BS 5839-1 for the permanent system and the relevant guidance for the temporary situation. Treating the works as a fixed picture is precisely the mistake to avoid.
The weight of interim measures
Interim measures deserve particular emphasis because occupied parts of the building still need appropriate detection and warning even while other parts are stripped out, altered or have their systems disturbed. Interim measures may be needed to maintain protection for those who remain in use of the building. From field experience, losing sight of this is exactly how an occupied area ends up quietly under-protected in the middle of a project — the permanent system partly disabled, and nothing put in its place. What interim measures are needed comes from the fire risk assessment for the works, reviewed as they progress, coordinated with BS 5839-1 and the relevant guidance for construction and occupied premises. Protecting the people still there is the non-negotiable part.
Managing phased occupation
Phased occupation adds its own dimension: when parts of a building are handed over and occupied while others are still being worked on, each occupied phase needs appropriate, working protection, and the boundary between finished and unfinished areas must be managed. The permanent system may be commissioned and brought into use in stages as areas are completed. How coverage is provided phase by phase comes from the fire risk assessment and the fire strategy, with the permanent system commissioned to BS 5839-1 as areas are finished, coordinated across the phases. The discipline is to make sure each newly occupied phase is genuinely protected before people move in, not shortly after.
Checking protection during works
On site during works, the checks centre on the people still using the building. Confirm occupied areas have appropriate, working detection and warning at all times, that any interim measures are in place and functioning, that disturbed or isolated parts of the system are documented and restored, and that the fire risk assessment for the works is current. From field experience, occupied areas left under-protected and parts of the system isolated without anyone realising are the serious findings on refurbishment jobs. Record the situation clearly — what is live, what is isolated, what is interim — and flag any gap in protection for occupied parts as a priority.
Common points to check
Recurring issues include occupied areas under-protected during works, system parts isolated without record, interim measures missing or not working, and a fire risk assessment for the works that is out of date. Confirming occupied areas are protected throughout is the essential check.
When not to rely on this alone
When not to use this article: do not use it as the fire safety plan for a specific project. That comes from the fire risk assessment for the works and the fire strategy, applied by competent professionals and kept under review as the works progress.
Relevant standards
The permanent system follows BS 5839-1, a code of practice, commissioned in stages as areas complete; interim protection during works follows the fire risk assessment for the works and the relevant guidance. The legal duty for fire precautions in most non-domestic premises, including during works, sits under the Regulatory Reform (Fire Safety) Order 2005, with Building Regulations statutory guidance in Approved Document B applying to building work. Separate the legal duty from the recommended methods, and always work to current editions.
Professional disclaimer
This is an educational and workflow resource for competent engineers and does not replace the current British Standards, the fire risk assessment for the works, the fire strategy, or competent judgement. Verify interim and permanent arrangements against current documentation, kept under review as works progress.
Related documentation
Use this with the current BS 5839-1, the fire risk assessment for the works and the fire strategy. Record what is live, isolated and interim at each stage, and flag any gap in protection for occupied areas.