3.4.2.4 — Travel Distance

(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 (b) except as permitted in Sentence (8) and Sentence 3.3.2.11. (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 mezzanine in a suite does not exceed 10% of the area of that suite. (5) Except as permitted by Sentences (6) and (7), 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 catwalks need not be considered as floor assemblies or mezzanines for the purpose of determining building height provided, (a) they are not used for storage, (b) they are constructed with noncombustible materials unless the building is permitted to be of combustible construction, and (c) where they are intended to be occupied, they have an occupant load of not more than four persons. (7) Mezzanines, elevated walkways and platforms that are intended to be occupied in Group F, Division 2 or 3 major occupancies need not be considered as storeys in calculating building height provided, (a) the building is of noncombustible construction, and (b) the occupant load is not more than four persons. (8) 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. (9) 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 3.2.5.15. and 3.3.1.23. and Sentences 3.2.4.20. (12), 3.2.7.3. (2), 3.3.1.3. (7), 3.4.2.4. (3) and 3.4.4.4. (9).

(1) Except as otherwise required by this Part or as permitted by Sentence (4), a public corridor shall be separated from the remainder of the storey by a fire separation. (2) Except as permitted by Sentence (3) and Clauses (4)(a) and (b), the fire separation between a public corridor and the remainder of the storey shall have a fire-resistance rating not less than 45 min. (3) If a storey is sprinklered, no fire-resistance rating is required for a fire separation between a public corridor and the remainder of the storey provided the corridor does not serve a care, care and treatment, detention or residential occupancy. (4) No fire separation is required in a sprinklered floor area between a public corridor and, (a) except as required by Sentences 3.3.3.5. (9) and 3.3.4.2. (1) and notwithstanding Sentences 3.4.2.4. (2), the remainder of a storey provided the travel distance from any part of the floor area to an exit is not more than 45 m., (b) a room or suite provided the public corridor complies with Sentence 3.3.1.9. (6) and Clause 3.4.2.5. (1)(d), or (c) a space containing plumbing fixtures required by Subsection 3.7.4. provided the space and the public corridor are separated from the remainder of the storey by a fire separation that has a fire-resistance rating not less than that required between the public corridor and the remainder of the storey. (5) The sprinkler system in Sentences (3) and (4) shall be electrically supervised in conformance with Sentence 3.2.4.10. (3) and, upon operation, shall cause a signal to be transmitted to the fire department in conformance with Sentence 3.2.4.8. (4) when the corridor serves a Group E or Group F, Division 1 or 2 occupancy.