Part I1 Class 9b buildings
Introduction to this Part
This Part provides additional Deemed-to-Satisfy Provisions for certain types of Class 9b buildings where large numbers of people assemble and which contain a stage and backstage area.
Deemed-to-Satisfy Provisions
I1D1
Application of Part
2019: H1.1
- the Deemed-to-Satisfy Provisions of Part I1 apply to every enclosed Class 9b building or part of a building which—
- is a school assembly, church or community hall with a stage and any backstage area with a total floor area of more than 300 m2; or
- otherwise, has a stage and any backstage area with a total floor area of more than 200 m2; or
- has a stage with an associated rigging loft; and
- notwithstanding (1)(a)—
Application of Part
- is a school assembly, church or community hall with a stage and any backstage area with a total floor area of more than 300 m2; or
- otherwise, has a stage and any backstage area with a total floor area of more than 200 m2; or
- has a stage with an associated rigging loft.
Explanatory information
Part I1 contains Deemed-to-Satisfy Provisions additional to those contained in Sections C, D and E for Class 9b buildings.
I1D2
Separation
2019: H1.2
A theatre, public hall or the like must—
- have a sprinkler system (other than a FPAA101D or FPAA101H system) complying with Specification 17; or
- have the stage, backstage area and accessible under stage area separated from the audience by a proscenium wall in accordance with I1D3.
I1D3
Proscenium wall construction
2019: H1.3
A proscenium wall must comply with Specification 32.
I1D4
Seating area
2019: H1.4
In a seating area—
- the gradient of the floor surface must not be steeper than 1 in 8, or the floor must be stepped so that—
- a line joining the nosings of consecutive steps does not exceed an angle of 30° to the horizontal; and
- the height of each step in the stepped floor is not more than 600 mm; and
- the height of any opening in such a step is not more than 125 mm; and
- if an aisle divides the stepped floor and the difference in level between any 2 consecutive steps—
- exceeds 230 mm but not 400 mm — an intermediate step must be provided in the aisle; and
- exceeds 400 mm — 2 equally spaced intermediate steps must be provided in the aisle; and
- the going of intermediate steps must be not less than 270 mm and such as to provide as nearly as practicable equal treads throughout the length of the aisle; and
- the clearance between rows of fixed seats used for viewing performing arts, sport or recreational activities must be not less than—
- 300 mm if the distance to an aisle is not more than 3.5 m; or
- 500 mm if the distance to an aisle is more than 3.5 m.
I1D5
Exits from stages
2019: H1.5
I1D6
Access to platforms and lofts
2019: H1.6
A stairway that provides access to a service platform, rigging loft, or the like, must comply with AS 1657.
I1D7
Aisle lights
2019: H1.7
In every enclosed Class 9b building, where in any part of the auditorium, the general lighting is dimmed or extinguished during public occupation and the floor is stepped or is inclined at a slope steeper than 1 in 12, aisle lights must be provided to illuminate the full length of the aisle and tread of each step.