There are specific provisions for large Class 6 buildings in E2D14 and E2D15 for the installation of either an automatic smoke exhaust system or automatic smoke-and-heat vents to control smoke during a fire. These apply to the whole fire compartment where the floor area of the Class 6 part of the fire compartment is more than 2 000 m².

There are specific concessions that vary these requirements. These are—

• for buildings where the floor area of the fire compartment does not exceed 3 500 m², it is permitted to install—
• an automatic smoke detection and alarm system in lieu of a smoke exhaust or smoke venting system if the building is single storey; or
• a sprinkler system if the building has a rise in storeys of not more than 2.
• for single storey shops with a floor area less than 2 000 m² (within a larger fire compartment) which have a main entrance opening to a road or open space and are smoke separated from the fire compartment. See Example 1.
• for another part of the building with a different classification (i.e. other than Class 6) which is smoke separated, including openings, junctions and joints of building elements, etc., from the Class 6 part. 
   

Example 1 

This example looks at a single storey shopping complex which does not contain a mall, as shown in Figure E2D14. The fire compartment has a floor area of 5 300 m2, so smoke exhaust/venting is required. The floor area of the fire compartment is more than 3 500 m2, therefore a smoke detection and alarm system or a sprinkler system cannot be used in lieu of smoke exhaust venting. However, smoke exhaust venting need not be provided in shops A and C because their individual floor areas are less than 2 000 m2, they are not interconnected to shop B, and their main entrances open to a road or open space. Smoke exhaust or smoke-and-heat venting must be provided to shop B. 

Figure E2D14: Plan of shopping centre for Example 1