Having read through all the sheltered housing threads I was still a bit bamboozled as to the requirements re the alarm configuration. Then I came across a guidance note from West Yorks FRS on the internet which contains the following
Fire originating in a dwelling
A fire alarm sounder should actuate in the dwelling only, and the warden should be alerted. Should the fire spread further and affect a smoke detector in another area or zone (e.g. the corridor outside the dwelling or an adjacent dwelling) then the alarm sounders in that area or zone should also operate.
The alarm sounders should operate in other adjacent dwellings or zones only if they become affected by subsequent fire or smoke spread.
Fire Originating Outside A Dwelling
Only the fire alarm sounder(s) within the zone of the fire should actuate, and the warden should be alerted. A zone should be considered to be an area within the building separated from the remainder by a minimum half hours fire resistance i.e. the corridor outside the dwellings.
The fire alarm sounders in the dwellings, or other zones, should not operate unless actuated directly within the area as a result of any subsequent fire or smoke spread.
Is this finally the clear clarification I was looking for, or.........well, any thoughts?