With schools facing a broader range of safety threats, many are rethinking how existing fire alarm systems could double up for lockdown and invacuation alerts. The FIA’s latest guidance unpacks the benefits, key considerations, and what BS 5839-1:2025 has to say about using fire detection and alarm systems for more than just fire.

03 June 2025

With safety concerns in schools extending beyond fire risks, more sites are exploring whether existing fire detection and alarm systems can also be used for lockdown and invacuation procedures. The FIA’s latest guidance note explores this dual use, highlighting the benefits, challenges, and what BS 5839-1:2025 has to say about it. Learn how fire alarm infrastructure could support safer, faster responses to threats both inside and outside the building.

In an evolving world of safety requirements, schools and other public buildings are increasingly looking at how existing infrastructure can support not only evacuation in the event of fire, but also lockdown and invacuation procedures in response to other threats. The FIA’s latest guidance note explores the use of fire detection and alarm (FD&A) systems for lockdown purposes, especially within the school environment.

Evacuation vs. Invacuation: A Shift in Safety Priorities

For those working within the FD&A industry, evacuation is a familiar goal—moving people away from danger when a fire occurs. This may be managed through staged, phased, or simultaneous evacuations depending on the building’s use, occupancy, and available systems.

However, there are growing scenarios where remaining inside the building is the safer option. Known as invacuation, this can be triggered by external hazards—such as:

  • A chemical spill or pollution incident
  • A dangerous animal spotted nearby
  • A security threat involving a violent intruder or potential attack

In schools, these risks have led to the development of lockdown procedures, where staff and pupils are required to stay put, close windows and doors, and avoid movement until the threat has passed.

What Is Lockdown and Why Alarm Systems Are Being Considered

A full lockdown is the most stringent form of invacuation. It restricts movement throughout a site, as well as access to and from the premises, to prevent potential attackers from entering or moving freely within the building. Unlike fire evacuations, which rely on clearly recognisable alarms and visual indicators, lockdown alerts are usually short, discreet, and carefully controlled to avoid triggering panic.

Traditionally, these two safety functions—evacuation and invacuation—have been delivered through entirely separate systems. However, the industry is now seeing growing interest in using a single fire detection and alarm system to deliver both functions.

Why Consider FD&A Systems for Lockdown?

  • Cost Efficiency: One system can be more economical than installing two.
  • Reliability: FD&A systems are typically built to high standards, ensuring minimal downtime and fault tolerance.
  • Infrastructure Readiness: With widespread coverage across a site, FD&A systems already provide an effective means of reaching all building users quickly.

What the Standard Says

BS 5839-1:2025 provides useful insight on this growing trend. Clause 5a of the standard notes:

“If a building contains alarm systems associated with hazards other than fire, the various hazard alarms need to be properly coordinated and be distinct from each other.”

In simple terms, if your fire alarm system is also being used to signal other emergencies, each alert must be clearly distinguishable, and the system must be designed so that one type of alarm doesn’t override or obscure another, particularly where the priority of threats may differ.

Although fire is usually given the highest priority, certain invacuation scenarios—especially in schools—could warrant a different risk hierarchy, and this needs to be agreed and planned for by the premises management team.

Things to Consider Before Implementation

The use of a fire alarm system for lockdown alerts must be approached thoughtfully:

  • Alarm Differentiation: Lockdown tones must be clearly distinct from fire alarms to avoid confusion.
  • Risk Assessment: Each school or building must assess whether invacuation might, in some cases, take priority over evacuation.
  • Operational Procedures: Clear and agreed protocols should be in place for situations where both types of alarm may be triggered simultaneously.
  • Stakeholder Engagement: School leadership, local authorities, emergency services, and system installers must collaborate to ensure safety and compliance.

Download the full Guidance Note.

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