Part I1 Class 9b buildings
Introduction to this Part
The Objectives and Functional Statements for Part HI1 are contained in Sections C, D and E of this Guide. The Performance Requirements for Part HI1 are contained in Sections C, D and E. Part HI1 contains additional Deemed-to-Satisfy Provisions for Class 9b buildings.
Application of Part
- the Deemed-to-Satisfy Provisions of Part I1 apply to every enclosed Class 9b building or part of a building which—
- notwithstanding (1)(a)—
To clarify which Class 9b buildings are subject to Part I1, and to what extent they are subject.
Class 9b buildings and high fire loads — I1D1(1)
Stages used for live performances can contain high fire loads due to the props, scenery, lighting, and the like used in such productions. Such props and scenery are often also stored in backstage areas, which adds to the fire load.
General application of Part I1
In general, Part I1 applies to specified enclosed Class 9b buildings which:
- in the case of school assembly, church or community halls, contain both a stage and backstage area which exceeds 300 m2;
- are not covered by I1D1(1)(a), and have a stage and backstage area which exceeds 200 m2; or
- have a stage with a rigging loft.
Part I1 does not simply apply to stage and backstage areas, but also to seating areas and aisle lighting.
I1D4 and all Class 9b buildings—I1D1(2)(a)
I1D4 applies to all Class 9b buildings, whether or not they are enclosed, and regardless of size.
I1D7 and all enclosed Class 9b buildings—I1D1(2)(b)
I1D7 applies to all Class 9b buildings which are enclosed, regardless of their size.
To protect the audience in a theatre or public hall from a fire on the stage.
I1D2 does not apply to all theatres and public halls. See I1D1 to determine which buildings need to comply with I1D2. A stage and backstage area of a theatre or public hall has a high fire load due to the storage of props and scenery/etc.
The audience must be protected from this fire source by either:
- the installation of a sprinkler system (other than a FPAA101Dor FPAA101H system); or
- the construction of a proscenium wall between the stage and the audience area.
Proscenium wall construction
To set out the detailed construction requirements for a proscenium wall.
The construction details for a proscenium wall are contained in Specification 32.
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.
To enable the evacuation of an audience from the seating area.
I1D4 applies to all Class 9b buildings
Under I1D1(2)(a), I1D4 applies to all Class 9b buildings, both enclosed and open. This means that it applies to theatres, open-deck spectator stands, sporting stadiums, and the like, wherever the public is seated to view an event.
Maximum slope of the floor — I1D4(a)
This slope cannot be used in aisles required to be accessible by people with disabilities. In such a case, the maximum slope of the aisle is 1 in 14, as required by AS 1428.1.
Height of openings in steps
Width of path of travel to an exit — I1D4(c)
It is often impractical to require the standard minimum width of a path of travel to an exit of one metre between rows of fixed seating. I1D4(c) allows a reduced width in such cases. This width is based on studies of movement between rows.
Distance between the seats should ordinarily be measured:
- with the seat in the up position if folding seats are used; or
- directly between the seats, as shown in Figure I1D4c.
I1D4(c) applies only where the public is seated on fixed seating to view an event.
Method of compliance with I1D4(b) if difference between levels is 230-400 mm.
Method of compliance with I1D4(b) if difference between levels is 400-600 mm.
Method of measurement of clearance between rows of fixed seating.
Exits from stages
To enable safe egress from the stage and backstage areas of a theatre.
A stage and backstage area of a theatre or public hall has a high fire load. It is also a potential fire source due to stored props, scenery, lighting, special effects, and the like.
Because of the recognised fire hazard, proscenium walls and curtains are required to separate the stage and backstage areas from the audience.
To maintain this fire separation:
- an evacuation route from the stage side of a proscenium must not pass through the proscenium; and
- required exits from backstage must be independent of the audience evacuation routes.
Access to platforms and lofts
A stairway that provides access to a service platform, rigging loft, or the like, must comply with AS 1657.
To set out the requirements for stairways to service platforms, rigging lofts, and the like.
Stairways to service platforms, rigging lofts, and the like must comply with AS 1657.
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.
To make safe evacuation available from theatres.
I1D7 applies to enclosed Class 9b buildings where:
- lighting is dimmed or extinguished during public occupation; and
- the floor is stepped or inclined at a slope steeper than 1 in 12.
In case of an evacuation, and when the lights are dimmed or extinguished during a performance, I1D7 requires the installation of aisle lights to avoid people tripping on steps or falling on a ramp.