3.2.1.1.Exceptions in Determining Building Height

(1) A rooftop enclosure provided for elevator machinery, a stairway or a service room used for no purpose other than for service to the building, shall not be considered as a storey in calculating the building height. (2) Space under tiers of seats in a building of the arena type shall not be considered as adding to the building height provided the space is used only for dressing rooms, concession stands and similar purposes incidental to the major occupancy of the building. (3) Except as required by Sentence (5), the space above a mezzanine need not be considered as a storey in calculating building height provided (a) the aggregate area of mezzanines that are not superimposed does not exceed 40% of the open area of the room in which they are located, and (See Note A-3.2.1.1.(3)(a)) (b) except as permitted in Sentences (7) and 3.3.2.13.(3) the space above the mezzanine is used as an open area without partitions or subdividing walls higher than 1 070 mm above the mezzanine floor. (4) Except as required by Sentence (5), the space above a mezzanine need not be considered as a storey in calculating the building height provided (a) the aggregate area of mezzanines that are not superimposed and do not meet the conditions of Sentence (3) does not exceed 10% of the floor area in which they are located, and (b) the area of a mezzanine in a suite does not exceed 10% of the area of that suite. (5) Except as permitted by Sentence (6), each level of mezzanine that is partly or wholly superimposed above the first level of mezzanine shall be considered as a storey in calculating the building height. (6) Platforms intended solely for periodic inspection and elevated maintenance catwalks need not be considered as floor assemblies or mezzanines for the purpose of calculating building height, provided (a) they are not used for storage, and (b) they are constructed with noncombustible materials unless the building is permitted to be of combustible construction. (7) The space above a mezzanine conforming to Sentence (3) is permitted to include an enclosed space whose area does not exceed 10% of the open area of the room in which the mezzanine is located, provided the enclosed space does not obstruct visual communication between the open space above the mezzanine and the room in which it is located. (See Note A-3.2.1.1.(3)(a) (8) A service space in which facilities are included to permit a person to enter and to undertake maintenance and other operations pertaining to building services from within the service space need not be considered a storey if it conforms to Articles 3.2.5.14. and 3.3.1.25., and Sentences 3.2.4.18.(11), 3.2.7.3.(2), 3.3.1.3.(7), 3.4.2.4.(3) and 3.4.4.4.(9). (See Note A-3.2.1.1.(8))