The guidance in B1 Section 1 of the Approved Document (fire alarm and fire detection systems) is not intended to be applied to the common parts of blocks of flats and does not include a provision to interconnect installations in separate flats.
Fire detection devices may need to be provided in some blocks to actuate automatic smoke control systems in the common parts of the building in accordance with paragraph 2.25. Such devices are not expected to be linked to a common alarm system.