3.4.3.2. 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

(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, care and 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

(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 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

(a)

the stairs provide not less than 0.3 m2 of area of treads and landings for each occupant of the interconnected floor space, or (See Note A-3.4.3.2.(6)(a))

(b)

protected floor space s 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.