Technical Booklet K Ventilation·Page 12
Definitions: Non-domestic building, Occupiable room
Defines non-domestic buildings as any building that is not used for residential purposes, and occupiable rooms as spaces in non-domestic buildings where people work or stay.
Non-domestic building – means a building or part of a building which is not a domestic building.
Ocupiable room – a room in a building other than a dwelling that is occupied by people, such as an office, workroom, classroom, hotel bedroom, etc. but not a bathroom, sanitary accommodation, utility room or rooms or spaces used solely or principally for circulation, building services plant or storage purposes.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet K - Ventilation.pdf