Do you have to have a separate fire alarm zone for the attic/loft area to the floors below?

I know Zones should not cross floors but is the attic/loft classed as a separate floor?

BS 5839-1:2013
13.2 Recommendations
13.2.1 Recommendations applicable to all detection zones

b) If the total floor area of the building is greater than 300 m2, each zone should be restricted to a single storey.

d) For voids above or below the floor area of a room, these may be included within the same zone of the room, provided that the voids and the room constitute a single fire compartment.

 

Depends whether you class it as a void or a floor. If the space is used and has an access ladder/stair I would be leaning towards calling it a floor, if a disused space more likely a void, but in the case of the latter would want remote indicators fitted.

Thanks AnthonyB