13.1 Commentary

To effectively direct the fire and rescue service during a fire alarm, buildings (except very small ones) need to be divided into detection zones. These zones should be small enough to quickly locate a fire. Even with addressable systems, detection zone indicators are necessary for faster identification of a fire's location compared to typical addressable text displays. Zone indicators also provide an easy overview of fire or smoke spread.

For manual call points, detection zone indication can be misleading as the person might activate it far from the fire's location, making zoning less beneficial in a Category M system.

If a detector is in an inaccessible area, a remote indicator is usually needed. However, in addressable systems, individual remote indicators may be unnecessary if each detector's location is clearly shown at the control and indicating equipment (CIE).

13.2 Recommendations

13.2.1 Recommendations applicable to all detection zones

The following recommendations are applicable.

Manual Call Points in Enclosed Stairways:

On each level (except the final exit level), manual call points should be included in the zone serving the adjacent accommodation on that level.
At the final exit to open air, manual call points within the stairwell can be included in the zone serving the stairwell.

Zone Restrictions Based on Building Floor Area:
For buildings with a total floor area greater than 300 m², each zone should be limited to a single storey.
For buildings with a total floor area less than 300 m², a zone can cover more than one storey.

Voids in Rooms:

Voids above or below the floor area of a room can be included in the same zone as the room if they form a single fire compartment.

13.2.2 Additional recommendations applicable to detection zones that contain only manual call points

The floor area of a single zone should not exceed 2 000 m2, other than in the case of a zone comprising mainly a single, open-plan area (e.g. an uncompartmented warehouse), which should not exceed 10 000 m2 in area.

13.2.3 Additional recommendations applicable to detection zones that contain non-addressable automatic fire detectors

The following recommendations are applicable.

Zone Floor Area:

A single zone should not exceed 2,000 m² in floor area.

Search Distance:

The search distance should not exceed 60 m.
Note 1: Responders need only become aware of the fire's location within this distance.
Note 2: Measure search distance considering the worst case, with the fire in the furthest concealed area from any likely entry point.

Enclosed Structures:

Automatic fire detectors in enclosed stairwells, lift wells, or other flue- like structures should be separate detection zones.
Manual call points at final exits to open air from stairwells can be included in these detection zones or in the adjacent accommodation zone.

13.2.4 Additional recommendations applicable to detection zones containing addressable

automatic fire detectors

The following recommendations are applicable.

Zone Indication:

● Zone indication should be provided at the Control and Indicating Equipment (CIE) even if addressable text information is also available.

Application of Recommendations:

The recommendations of 13.2.3 apply, except for 13.2.3b if:
Clear addressable text display of the location of at least the first detector responding to a fire is available at the CIE without manual intervention.
The display, along with other necessary information on or near the CIE, enables firefighters unfamiliar with the building to locate the fire.

NOTE For example, the CIE might provide a text indication of room number, and a plan adjacent to the CIE might show the location of the room.

13.2.5 Remote indication of detector operation

Remote indicators should be clearly labeled to indicate their function and should be positioned or labeled to help identify the location of the detectors they serve. Any cable connecting a detector to a remote indicator must comply with and be installed according to the recommendations of section 26.2 of BS 5839.

NOTE Remote indicators might be required in a specification for areas such as inaccessible voids or locked rooms. See also 40.2 for the as-fitted drawing.

Figure 2 — Examples of search distances in an open area [see 13.2.3b)]

13 Detection zones