Common Alarm Systems and Waking Watch in High-Rise
When a high-rise residential building's fire safety is found to be defective, its intended fire strategy — often stay put — may no longer be safe to rely on, and something has to fill the gap until the defects are fixed. For a while that something was frequently a waking watch: people patrolling to raise the alarm. Increasingly it is a common fire alarm system that warns everyone to evacuate at once. Both are interim measures, and the fire alarm engineer meets the second directly. This guide covers what they are and what to check.
The central point is that waking watches and common (simultaneous evacuation) alarm systems are interim measures for high-rise buildings with fire safety defects, in place until remediation restores the intended strategy.
Who this is for
This is for competent fire alarm engineers who encounter interim measures in high-rise residential buildings. The experience level assumed is competent engineer. Use this as orientation; whether such measures are appropriate comes from the fire risk assessment and the responsible person's arrangements, informed by national guidance. The common alarm system aspects follow BS 5839-1; the wider interim strategy rests with the responsible person.
Waking watch as an interim measure
A waking watch is an interim fire safety measure — trained staff patrolling a building to detect fire and alert residents — used in some high-rise residential buildings with fire safety defects, typically where a stay-put strategy can no longer be relied upon pending remediation. It is a temporary, management-based measure rather than a system, and it depends entirely on people. Where used, it and any move to simultaneous evacuation follow the fire risk assessment and the responsible person's arrangements, informed by national guidance. The key point is that a waking watch is a stopgap covering a building whose built-in fire strategy is temporarily compromised, not a permanent state of affairs.
Common alarm systems as an alternative
In many buildings, a common (simultaneous evacuation) fire alarm system has been installed as a more reliable alternative to, or to reduce reliance on, a waking watch — providing automatic detection and warning so that all residents can be alerted to evacuate at once. Government funding has supported such installations in buildings with fire safety defects, reflecting a view that an automatic system is generally more dependable than human patrols. For the engineer, this is the tangible part: a real fire alarm installation following BS 5839-1, serving an interim simultaneous evacuation strategy. Whether it is appropriate comes from the fire risk assessment and the building's interim strategy, but installing and maintaining it well is squarely fire alarm work.
Interim, not permanent
It is important to hold on to the interim nature of these measures. They are generally in place for buildings with identified fire safety defects, pending remediation that restores the building's intended strategy — a waking watch or a common alarm system supports safety while the underlying defects are addressed, rather than being the permanent solution. From the engineer's side, that means the common alarm system is doing a critical job for as long as the defects remain, and its reliability matters acutely during that period. Whether and how long it is needed comes from the fire risk assessment and the remediation programme; the fire alarm aspects follow BS 5839-1 and the interim strategy.
Checking a common alarm system
Where a common alarm system is installed as an interim measure, it deserves rigorous attention because residents' safety leans on it. Confirm it provides reliable detection and warning to all residents as intended, that it matches the building's interim simultaneous evacuation strategy, and that it is properly maintained. From field experience, a common alarm system that does not reliably warn all residents — a flat where the warning is inaudible, a section not covered — or that no longer matches the strategy, is a serious concern while defects remain. Record findings, and flag any gap to the responsible person promptly, since the whole point of the interim measure is that everyone can be warned and can evacuate.
Common points to check
Recurring issues include a common alarm system that does not reliably warn all residents, coverage or audibility gaps, and a system no longer matching the interim strategy. Confirming reliable warning to all residents is the essential check while defects remain.
When not to rely on this alone
When not to use this article: do not use it to decide interim measures for a specific building. Those come from the fire risk assessment and the responsible person, informed by national guidance; the fire alarm aspects follow BS 5839-1.
Relevant standards
The common alarm system follows BS 5839-1, a code of practice, within the building's interim strategy; interim measures follow the fire risk assessment and national guidance. The legal duty for fire precautions in relevant premises sits under the Regulatory Reform (Fire Safety) Order 2005. Separate the legal duty from the recommended methods, and always work to current editions and current guidance.
Professional disclaimer
This is an educational and workflow resource for competent engineers and does not replace the current British Standards, the fire risk assessment, national guidance, or competent judgement. Verify interim arrangements against current documentation and guidance.
Related documentation
Use this with the current BS 5839-1, the fire risk assessment and the relevant national guidance. Record the common alarm system's coverage and condition, and flag any gap in warning to all residents to the responsible person.