When applying the LACoRS guidance to houses converted to self-contained flats (prior to 1991) is the extent of the shared internal communal area irrelevant when counting the number of storeys (section 37)?
For example, a three storey property has only a small communal lobby at ground floor level only with two flat entrance doors located within this lobby. Flat A occupies the ground floor only. Flat B occupies the upper two floors and the stairs are entirely within this flat (technically flat B is over three floors as its entrance is at ground floor level).
As this is a three storey property, then Case Study D11 applies and a Grade A LD2 system (with control panel and call point) is recommended in the (small) common area linked to heat alarms in the entrance/lobby of each flat.
Have I interpreted the guidance this correctly?
Further, if there is a basement/lower ground floor flat in the block (flat C) that has its own separate external entrance and has no access to the communal area, does this flat also require a heat alarm linked to the communal system?