Exit Width Based on Occupant Load
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), the required exit width shall be cumulative if 2 or more exits converge.

Exit Width
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
   1. 6.1 mm per person for ramps with a slope of not more than 1 in 8, doorways, corridors and passageways,
   2. 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
   3. 9.2 mm per person for
      1. ramps with a slope of more than 1 in 8, or
      2. stairs, other than stairs conforming to Clause (b).
2. The minimum aggregate width of exits serving floor areas intended for a care, treatment 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
   1. 1.8 mm per person for
      1. aisles,
      2. stairs other than exit stairs, and
      3. ramps and passageways in vomitories and exits, and
   2. 2.4 mm per person for exit stairs.
4. Except as required by Sentences 3.4.3.2.(5) and (6), 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 Sentence (6).
6. The required exit width for exit stairs that serve interconnected floor space designed in accordance with Articles 3.2.8.3. to 3.2.8.8. shall be cumulative, unless
   1. the stairs provide not less than 0.3 m2 of area of treads and landings for each occupant of the interconnected floor space (see Note A-3.4.3.2.(6)(a)), or
   2. protected floor spaces conforming to Article 3.2.8.5. are provided at each floor level and the protected floor space on a floor level has not less than 0.5 m2 of space for each occupant of that floor level of the interconnected floor space. (See Note A-3.4.3.2.(6).)
7. If more than one exit is required, every exit shall be considered as contributing not more than one half of the required exit width.
8. The minimum widths of exits shall conform to Tables 3.4.3.2.-A and 3.4.3.2.-B.

Table 3.4.3.2.-A
Minimum Widths of Exit Corridors, Passageways, Ramps, Stairs and Doorways in Group A, Group B, Division 1, and Groups C, D, E and F Occupancies
Forming Part of Sentence 3.4.3.2.(8)

Notes to Table 3.4.3.2.-A:
(1) Serving not more than 2 storeys above the lowest exit level or not more than 1 storey below the lowest exit level.
(2) Serving more than 2 storeys above the lowest exit level or more than 1 storey below the lowest exit level.

Table 3.4.3.2.-B
Minimum Widths of Exit Corridors, Passageways, Ramps, Stairs and Doorways in Group B, Division 2 and Division 3 Occupancies
Forming Part of Sentence 3.4.3.2.(8)

Notes to Table 3.4.3.2.-B:
(1) Minimum widths of ramps, stairs and doorways do not apply within individual suites of care occupancy.
(2) Serving not more than 2 storeys above the lowest exit level or not more than 1 storey below the lowest exit level.
(3) Serving more than 2 storeys above the lowest exit level or more than 1 storey below the lowest exit level.

Exit Width Reduction
1. Except as permitted by Sentences (2) and (4), no fixture, turnstile or construction shall project into or be fixed within the required width of an exit.
2. 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.
3. Doors shall be installed so that, when open, they do not diminish nor obstruct the required width of the exit.
4. Handrails and construction below handrails, including handrail supports and stair stringers, shall not project more than 100 mm into the required width of a means of egress.

Headroom Clearance
(See Note A-3.4.3.4.)
1. Except as permitted by Sentences (4) and (5), every exit shall have a clear height over the clear width of the exit of not less than 2 050 mm.
2. The clear height of stairways shall be measured vertically over the clear width of the stairway, from the straight line tangent to the tread and landing nosings to the lowest element above. (See Note A-9.8.7.4.)
3. The clear height of landings shall be measured within the clear width of the landing vertically to the lowest element above.
4. Except as permitted by Sentence (5), the headroom clearance for doorways shall be not less than 2 030 mm.
5. 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.