The Australian Building Codes Board (ABCB) would like the Building Code of Australia (BCA) or now National Construction Code (NCC) to be the single point of reference for everything in the built environment. I don't believe this is appropriate. The BCA is fundamentally about habitable buildings, and in the main the performance criteria are for spaces not for the fabric of the building: the BCA has very little about buildings. Which as a point suggests the BCA is equally applicable to an open work space. Anycase, anything which is not a habitable building is classified as a class 10 building. If a building is class 10, then BCA requirements are found in BCA volume 2. Now BCA volume 2 is little more than a prescriptive solution for housing, and contains fewer performance criteria than BCA volume 1.
We have two major codes for the built environment, the BCA and the bridge code. For the most part however building works are captured by the Development Act and go into the local city/district council for development approval. This therefore means initial review is against the Building Rules and that basically means the BCA, and if the building works do not relate to a habitable building then it means BCA volume 2 the prescriptive solution for housing. A bridge is not a habitable building, it is therefore a class 10 building and governed by BCA volume 2, a prescriptive solution for housing.
Common sense may prevail, however the law is not about common sense, it is about what is written and what is intended. For highway and railway bridges its obvious that the bridge code should control. Further more unlikely to be placed into council for development approval as design most likely placed out to tender by the approving authority in the first instance.
But bridges are not the only structure which are not habitable buildings. So if the BCA is the single point of entry for the built environment then the following are class 10 buildings governed by a prescriptive solution for housing:
2) Tall radio mast
3) Water tank
4) Silo's, Bins and Bunkers
5) Fixed Gantry Cranes
6) Industrial Chimneys
7) Oil refinery
8) Power Station
9) Large scale solar array
10) Wind turbine
11) Earth Retaining Structures and Coastal defence structures
12) Advertising Signs
13) Sports Safety nets
14) Agricultural Buildings/Shelters
15) Radar Dish
16) Large Scale Optical Telescope
17) Large open air machine and electrical systems
It is also to be noted that most Australian Standards comprising our structural codes (eg. AS1170, AS4100) also all relate to buildings, not to structures in general.
If we are to have legislation which captures all artificial systems placed in the environment, then it needs to provide performance criteria appropriate to each technology, not just appropriate to habitable buildings.