Alternative to required fire-isolated stairways or ramps

Compliance with D2D13 for external stairway or ramp is only required where the external stairway or ramp is proposed as an alternative to a required fire-isolated stairway or ramp. In other words, if a fire-isolated stairway or ramp is not required by the BCA, compliance is not required with D2D13.

External stairways and ramps permitted to 25 metres

The use of an external stairway or ramp is permitted instead of a fire-isolated stairway or ramp up to a height of 25 metres. The reason external stairways or ramps are not permitted above this height is because of:

• the risk that people would suffer vertigo above this level;
• the risk that weather conditions, particularly wind, may become more severe above this height; and
• the need to enable any person who gets into difficulties on the stairway to be rescued by way of fire brigade ladders or other rescue equipment, which generally do not reach above this height.

Fire protection required

Fire protection from the external wall of the building near the external exit and any openings in that wall, is required under D2D13(1) and (2) to ensure that an average person using the exit is afforded adequate protection from flames and radiant heat from a fire within the building.

D2D13(3) provides two separate methods of protecting the external exit from a fire from within the building:

• protect the external wall of the building and any openings in the wall, within the prescribed distances to the exit (see Figure D2D13a); or
• protect the exit by shielding construction where the exit is within the prescribed distances to the building (see Figure D2D13b).

D2D13(4) provides requirements for the shielding construction and protection of any openings in that construction.

Figure D2D13a: Protection of the external exit using the external wall of building in accordance with D2D13(3)(a)

Figure D2D13b: Protection of the external exit using shielding construction in accordance with D2D13(3)(b)