Town Planning is a separate university degree discipline, which is usually guided by the interest of the general community & attempts to solve development problems.
The Acts also detail time frame limitations, registration & licensing body requirements of building professionals, practitioners & trade contractors.
The Building Certifier interacts with all professionals & often the Senior trade contractors engaged within the building & inspects the works as they proceed, during mandatory inspection phases of footings, slab, frame, fire separation & final, to ensure compliance with the approved plans, the NCC & relevant Australian Standards.
Plumbing works are generally approved & inspected at various stages, by the Local Authority (Council) Plumbing Inspectors who have a Hydraulic/Plumbing trade qualification & experience, to ensure public potable water safety, contain the spread waste-water products & regulate responsible ground water discharge.
Larger infrastructure i.e. dams, pipe line networks, roadway drainage, flood mitigation works, etc, calls for a Civil Engineering background.
On May 17, 1926,[4] the International Association of Plumbing and Mechanical Officials, or IAPMO, began with a mandate “to advance the latest and most improved methods of sanitation; to promote the welfare of and harmony between the owner, the builder, and the craftsman; to accomplish a uniformity in the application of the provisions of the ordinances; and to promulgate the mutual benefit of the members."
The Secretary of State issues guidance in support of the Building Regulations in the form of Approved Documents which are not mandatory.
The burden of proof is then placed on the designers to demonstrate that the alternative solution proposed offers a level of performance which satisfies the intent of the functional requirement.
There is nothing in the Regulations which imposes a duty on the applicant under those circumstances to use the guidance as a benchmark of performance, although this is of course a route often taken as a way of demonstrating that an alternative approach is of an acceptable standard.