Selection & Installation of Electrical Equipment for Baths, Showers and other fixed water containers Table 6.1 (Information here to help the Builder. More Information for the builder with the updates available via National Construction Code of Australia) Earthing of conductive reinforcing in combined outbuildings that contain showers / baths.
One Example of Distances from fixed plumbing. Requirement of Bonding of your Shower mesh in the concrete & concrete walls of your shower.
Refer to all aspects relaxed to baths & showers as in fully detailed within ASNZ3000:2018 Section 6.2 you can purchase a copy from SAI Global (Refer your builder to the current building codes)