3.2.3.19 — Walkway between Buildings

(1) Except as required by Sentences (3) and 3.2.3.13. (1) or as permitted by Sentence 3.2.3.19. (4), if an unprotected opening in an exterior wall of a fire compartment is exposed to an unprotected opening in the exterior wall of another fire compartment, and the planes of the two walls are parallel or at an angle less than 135, measured from the exterior of the building, the unprotected openings in the two fire compartments shall be separated by a distance not less than DO, where, DO =2D – [(θ/90) × D] but in no case less than 1 m, and D =the greater required limiting distance for the exposing building faces of the two fire compartments, and θ =the angle made by the intersecting planes of the exposing building faces of the two fire compartments (in the case where the exterior walls are parallel and face each other, θ = 0). (2) The exterior wall of each fire compartment referred to in Sentence (1) within the distance, DO, shall have a fire-resistance rating not less than that required for the interior vertical fire separation between the fire compartment and the remainder of the building. (3) Sentence (1) does not apply to unprotected openings of fire compartments within a building that is sprinklered, but shall apply to, (a) unprotected openings of fire compartments on opposite sides of a firewall, and (b) exposure from unprotected openings of a fire compartment that is not protected by an automatic sprinkler system.

(1) Except as permitted by Sentence 3.2.3.19. (4), if a wall in a building is exposed to a fire hazard from an adjoining roof of a separate fire compartment that is not sprinklered in the same building, and the exposed wall contains windows within 3 storeys vertically and 5 m horizontally of the roof, the roof shall contain no skylights within 5 m of the exposed wall.

(1) An underground walkway shall not be designed or used for any purpose other than pedestrian travel unless, (a) the purpose is permitted, and (b) sprinklers are installed in any space in the walkway containing an occupancy. (2) Buildings connected by an underground walkway shall be separated from the walkway by a fire separation with a fire-resistance rating not less than 1 h. (3) An underground walkway shall be of noncombustible construction suitable for an underground location. (4) In an underground walkway, (a) smoke barrier doors shall be installed at intervals of not more than 100 m, or (b) the travel distance from the door of an adjacent room or space to the nearest exit shall be not more than one and a half times the least allowable travel distance to an exit for any of the adjacent occupancies as permitted by Sentence 3.4.2.5. (1). (5) An underground walkway between buildings shall be not more than 9 m wide.