The height of a Balustrade or Barrier must not be less than 1m above the floor of any access path, balcony, landing where it is not bounded by a wall and its level above the surface is 1m or more than 4m where a person is able to fall through an open window.
The National Construction Code (NCC) provides the minimum necessary requirements for safety, health, amenity and sustainability in the design and construction of new buildings (and new building work in existing buildings) throughout Australia. It is a uniform set of technical provisions for building work and plumbing and drainage installations throughout Australia whilst allowing for variations in climate and geological or geographic conditions.
The NCC is an initiative of the Council of Australian Governments (COAG) developed to incorporate all on-site construction requirements into a single code. The NCC is comprised of the Building Code of Australia (BCA), Volume One and Two; and the Plumbing Code of Australia (PCA), Volume Three.
Pertinent to wire balustrade and handrail systems are the following:
NCC 2016 Volume One primarily applies to Class 2 to 9 (multi-residential, commercial, industrial and public) buildings and structures.
NCC 2016 Volume Two primarily applies to Class 1 (residential) and 10 (non-habitable) buildings and structures. If you're building a wire balustrade system for your home or you're contracted to build it for residential premises, then please refer to this resource.