[FONT=Arial,Helvetica][SIZE=-1][SIZE=-1]S[/SIZE]ounds like an L3 Fire system, [SIZE=-1]--- [/SIZE]only installed for the protection of escape routes.[/SIZE][/FONT]
The best system design (student lets) is normally an L3 ,then the bedsits get there own smokies from the consumer unit. This reduces the false alarms, as the bedsit would sound first, if it was a real fire then the main system would pick up and alert rest of building and the landlord has ticked the boxes for HMO.
However, if its just this system only and possibly a detector within each flat, then it may need additional sounders, to wake up anyone within that room. Maybe another risk assessment should be carried out
To replace the panel would be a Alteration cert, and you would only have to test a device on each zone, not a full re-commission also.
Hope this helps you a little, i think it makes sense lol, im sure someone will correct if im wrong.