Thanks to all for your input. Things are now starting to clarify, it appears that on conversion a stay put policy was adopted and approved by the authorities assuming 60mins compartmentation. The common areas fire detection system was installed later by a new owner and configured as a staff alarm system supported by a 24/7 security team on site who would investigate any alarm and only operate the evacuation signal if a serious fire were confirmed. The sounders would then be operated from the panel in the security office. When the security team were then disbanded and a concierge replaced them the alarm was simply reconfigured to sound an evacuation on detection of a fire.
Since then the IT and cable teams have been in and knocked hell out of the compartmentation so I have suggested three alternatives-
1- put back the compartmentation and revert to a stay put policy and reconfigure the alarm system to operate ventilation of staircases and fire fighting lobbies (currently manual opening and very difficult to reach)
2- put in place a security team 24/7 as per the original fire alarm design
3- If the compartmentation cannot be fully relied on operate an all out strategy in the event of heat in a flat or smoke in the common areas, but then it will be necessary to install void detection and break glass call points with alarmed covers or another means to enable persons to raise the alarm if they discover a fire.
