VCONST14190 - Dwellings - an explanation of terms: what ‘designed as a dwelling or number of dwellings’ means: shared living and leisure facilities in blocks of flats
Shared living and leisure facilities in blocks of flats, such as lounges, laundries, swimming pools that are used only by the residents and their guests are accepted as part of a building designed as number of dwellings.
Where such facilities are partly used by others, whether or not for a charge, they aren’t part of a building designed as a number of dwellings.