From the 'Bible':
"Manual call points need to be prominently sited, readily distinguishable from non-fire alarm call points and need to be distributed such that, from any point in the building, it is impossible to leave the storey or the building without passing a manual call point.
Sufficient call points need to be provided to minimize, to a reasonable extent, the delay between discovery of a fire and the sounding of the alarm. Where the fire hazard level is high and rapid fire development is anticipated, this delay needs to be commensurately shorter.
Manual call points should be located on escape routes and, in particular, at all storey exits and all exits to open air (whether or not the exits are specifically designated as fire exits).
Those located at storey exits may be sited within the accommodation or on the landing of a stairway to which the storey exit gives access."
If each stair is still in situ and is a exit then each door from each block floor that leads onto the stairs would be a storey exit