Fire Alarm Systems

Fire alarm systems are essential for life safety and property protection, governed primarily by the Regulatory Reform (Fire Safety) Order 2005 and detailed in British Standards such as BS 5839. Systems vary widely in complexity, from simple manual alarms to sophisticated addressable networks, and are categorised based on their purpose and coverage

Types Of Systems

Fire alarm systems are categorised by how their components communicate: 

  • Conventional: The building is divided into "zones," and multiple detectors and call points are wired to each zone circuit. The control panel indicates the activated zone, but not the exact device. Suitable for smaller, lower-risk buildings.
  • Addressable: Each individual device on the system has a unique electronic address, allowing the control panel to pinpoint the exact location of the alarm. This is ideal for larger, more complex premises like hospitals or hotels, where rapid and precise location identification is crucial.
  • Wireless: These systems operate similarly to addressable systems but use secure radio frequency communication instead of cables, making them ideal for historic buildings or premises where extensive wiring is difficult. 

Categories (Protection Level)

British Standard BS 5839 defines system categories based on their purpose and coverage: 

  • Category M: Manual systems only, relying solely on manual call points for activation.
  • Category L (Life Protection): Designed to protect human life.
    • L1: Maximum life protection; automatic detection throughout all areas of the building.
    • L2: Detection in all escape routes, rooms opening onto escape routes, and high-risk areas (e.g., kitchens, boiler rooms).
    • L3: Detection in escape routes and rooms opening onto them, giving early warning so occupants can exit before routes are blocked by smoke.
    • L4: Detection in escape routes and circulation areas only.
    • L5: A "custom" category for specific fire risks identified by a fire risk assessment.
  • Category P (Property Protection): Designed to protect the building and its assets, aiming for the earliest possible fire brigade notification to minimise damage.
    • P1: Automatic detection throughout the entire building.
    • P2: Detection only in specific high-risk areas. 

The selection of the appropriate system is determined by a detailed fire risk assessment, which is a legal requirement for all non-domestic premises. Installation and maintenance should be carried out by competent, third-party certified providers to ensure compliance with the relevant standards.