Fire Alarm Categories Explained
Clearing up confusion around fire alarm categories, responsibilities and the latest Fire Industry Association (FIA) guidance this Fire Alarm Categories Explained guide helps duty holders understand who is responsible for selecting the correct system and how categories should be applied in practice.
Fire alarm categories have remained largely unchanged for many years. However, confusion around how they should be applied and who is responsible for choosing them continues to cause uncertainty across the fire safety industry.
To address this, the Fire Industry Association (FIA) has released updated guidance. Rather than introducing new categories, the guidance focuses on providing much needed clarity around responsibility, correct application and best practice when specifying fire alarm systems.
What’s Changed and What Hasn’t
When it comes to Fire Alarm Categories Explained, the categories themselves remain the same:
- Manual fire alarm systems (Category M)
- Life protection systems (Categories L1-L5)
- Property protection systems (Categories P1-P2)
What has changed is the clarity around who is responsible for defining the appropriate fire alarm category for a building and what supporting information must be provided to ensure systems are correctly specified from the outset.
The updated FIA guidance clearly states that selecting the correct fire alarm category is not the responsibility of the fire alarm system designer or contractor. Instead, this responsibility sits firmly with the fire safety specialist.
Who Is Responsible for Selecting a Fire Alarm Category?
According to the updated FIA guidance, responsibility for determining the appropriate fire alarm system category lies with qualified professionals such as:
- Fire risk assessors
- Fire engineers
- Fire safety consultants
- Enforcing authorities and building control bodies
As part of this approach, these professionals are responsible for assessing risk, building use and compliance requirements. They must then clearly communicate the required fire alarm category, along with any additional system requirements to the fire alarm designer.
This distinction is critical. While fire alarm designers may have significant technical expertise, the guidance reinforces that system design should be based on clearly defined requirements, not assumptions.
When Additional Detail Is Required
In many cases, simply stating a fire alarm category is not enough. The FIA guidance highlights that, aside from Categories M, L1, P1 and L4, further detail should be provided to support correct system design.
This additional information may include:
Category L2
- Which additional rooms or areas require protection beyond Category L3
- The type of fire detection required in those areas
Category L3
- The type of detector to be installed in rooms or areas opening onto escape routes
Category L5
- The specific fire safety objective
- The protected areas and detector types
- Information typically informed by a detailed fire risk assessment
Category P2
- Which areas require property protection
- Why protection is required, often linked to business interruption or asset protection risk
- Providing this level of clarity early in a project helps prevent misunderstandings, redesigns and costly disputes later.
Supporting Better Compliance and Fewer Disputes
The updated FIA guidance also encourages clearer communication between duty holders, fire safety specialists and fire alarm system designers before installation begins.
Following best practice outlined in this guidance supports:
- Better aligned fire alarm system specifications
- Reduced project disputes and variations
- Stronger compliance with fire safety legislation and BS 5839-1
It also reinforces the importance of robust fire risk assessments, particularly when specifying Category L5 systems and property protection fire alarm systems.
Review Our Fire Alarm Design Categories
For a clear overview of each fire alarm category and how they are typically applied, explore our dedicated Fire Alarm Design Categories page: Fire Design Categories | BS5839 Fire Alarm Classifications | Marlowe Fire & Security
This page complements this guide by providing clear definitions and practical examples of how each category is intended to be used.
Download the FIA Guidance on Fire Alarm Categories
To support industry wide clarity, the FIA guidance offers a concise and practical reference covering:
- Fire alarm Categories M, L1-L5 and P1-P2
- Typical applications across different building types
- Key considerations from the BS 5839-1 update
Get Expert Support
Whether you’re responsible for specifying fire alarm systems or ensuring ongoing compliance, this Fire Alarm Categories Explained guidance provides valuable insight into current best practice.
By understanding responsibilities and applying fire alarm categories correctly, duty holders can improve compliance, reduce risk and avoid costly misunderstandings.
At MFS, our dedicated fire alarm design team can support you with all aspects of fire alarm specification and system design. We help ensure the correct application of fire alarm categories and full compliance from the outset.
Get in touch today to discuss your requirements.