3.4.3.

(1) For the purpose of determining the aggregate width of exits, the occupant load of every room or floor area shall be determined in conformance with Subsection 3.1.17.

(2) Except as permitted by Sentence 3.4.3.2.(4)v1, the required exit width shall be cumulative if 2 or more exits converge.

(1) Except as permitted by Sentence (3), the minimum aggregate required width of exits serving floor areas intended for assembly occupancies, residential occupancies, business and personal services occupancies, mercantile occupancies, and industrial occupancies shall be determined by multiplying the occupant load of the area served by,

(a) 6.1 mm per person for ramps with a slope of not more than 1 in 8, doorways, corridors and passageways,

(b) 8 mm per person for a stair consisting of steps whose rise is not more than 180 mm and whose run is not less than 280 mm, or

(c) 9.2 mm per person for,

(i) ramps with a slope of more than 1 in 8, or

(ii) stairs, other than stairs conforming to Clause (b).

(2) The minimum aggregate width of exits serving floor areas intended for a care or detention occupancy shall be determined by multiplying the occupant load of the area served by 18.4 mm per person.

(3) The minimum aggregate width of means of egress serving a Group A, Division 4 occupancy shall be determined by multiplying the occupant load of the area served by,

(a) 1.8 mm per person for

(i) aisles,

(ii) stairs other than exit stairs, and

(iii) ramps and passageways in vomitories and exits, and

(b) 2.4 mm per person for exit stairs.

(4) Except as required by Sentence (5) and the required exit width need not be cumulative in an exit serving 2 or more floor areas located one above the other.

(5) The required exit width for an exit stair in an assembly hall or theatre serving more than one balcony level shall conform to the appropriate requirements for stairs serving interconnected floor spaces in Article 3.2.8.4.

(6) If more than one exit is required, every exit shall be considered as contributing not more than one half of the required exit width.

(7) The width of an exit shall be not less than,

(a) 1 100 mm for corridors and passageways,

(b) 1 100 mm for ramps not serving patients’ or residents’ sleeping rooms,

(c) 1 100 mm for stairs, not serving patients’ or residents’ sleeping rooms, that serve more than two storeys above the lowest exit level or more than one storey below the lowest exit level,

(d) 900 mm for stairs, not serving patients’ or residents’ sleeping rooms, that serve not more than two storeys above the lowest exit level or not more than one storey below the lowest exit level,

(e) 1650 mm for stairs and ramps serving patients’ or residents’ sleeping rooms,

(f) 1 050 mm for doorways serving patients’ or residents’ sleeping rooms, and

(g) 790 mm for doorways not serving patients’ or residents’ sleeping rooms.

(1) Exit stairs that serve interconnected floor spaces as provided in Articles 3.2.8.3. to 3.2.8.11. shall conform to the requirements in Article 3.2.8.4. and in this Section.

(1) Except as permitted by Sentences (2) to (4), no fixture, turnstile or construction shall project into or be fixed within the required width of an exit.

(2) Exit doors shall be hung so that, when open, they shall neither diminish nor obstruct the required width of the exit by more than 50 mm for each door leaf.

(3) Swinging doors in their swing shall not reduce the required width of exit stairs or landings to less than 750 mm or reduce the width of an exit passageway to less than the minimum required width.

(4) Handrails and construction below handrails are permitted to project into the required width of means of egress but the projections shall be not more than 100 mm on each side of the required width.

(5) In an elementary or secondary school, where a stair lift is installed in an exit stair, an intermediate handrail shall be installed between the path of travel of the stair lift and the remainder of the stair to ensure that the stair lift will not reduce the required width of the exit stair.

(1) Except as permitted by Sentences (2) to (4), every exit shall have a headroom clearance of not less than 2 100 mm.

(2) The headroom clearance for stairways measured vertically above any landing or the nosing of any stair tread shall be not less than 2 050 mm.

(3) Except as permitted by Sentence (4), the headroom clearance for doorways shall be not less than 2 030 mm.

(4) No door closer or other device shall be installed so as to reduce the headroom clearance of a doorway to less than 1 980 mm.