(1) The requirements restricting fire spread and collapse for a building of a single major occupancy classification are provided in this Subsection according to its building height and building area.
                                
                                
                                (2) If a building contains more than one major occupancy, classified in more than one Group or Division, the requirements of this Subsection concerning building size and construction relative to major occupancy shall apply according to Articles 3.2.2.5. to 3.2.2.8.
                                
                                
                                (3) For the purposes of Sentences (1) and (2), a retirement home is deemed to be a separate major occupancy.