For the purposes of this chapter, buildings are classified with respect to occupancy and use as public buildings, residence buildings, business buildings and storage buildings.
A.
Mixed occupancy. In case a building is occupied for two or more purposes not included in one class, the provisions of the chapter applying to each class of occupancy shall apply to such part of the building as comes within that class, and if there should be conflicting provisions, the requirements securing the greater safety shall apply.
B.
Doubtful classification. In case a building is not specifically provided for or where there is any uncertainty as to its classification, its status shall be fixed by a duly promulgated rule giving due regard to safety.