The Building Act, Division 2 - Codes of conduct for building practitioners states:
177 Authority may approve codes of conduct for building practitioners.
(1) The Authority may approve codes of conduct for building practitioners in accordance with this division.
(2) A code of conduct may make different provisions for different categories or classes of building practitioners.
http://www.legislation.vic.gov.au/domino/Web_Notes/LDMS/LTObject_Store/ltobjst9.nsf/DDE300B846EED9C7CA257616000A3571/A080756F8B80586BCA25802000788925/$FILE/93-126aa107%20authorised.pdf
I have been unable to find any codes of conduct. Does anybody know whether any have been published?