Reasons for different requirements

Some areas are only accessed by maintenance or specialist workers. In such areas, access and egress requirements for members of the public no longer apply, and the requirements are permitted to fall outside the various measurements applying elsewhere.

In Class 2 buildings or Class 4 parts, this includes non-habitable rooms such as attics, storerooms and the like that are not used on a frequent or daily basis. In such cases, the designer has the choice of designing the stair, landing, barrier and handrail to comply with the appropriate provisions of the NCC or with AS 1657.