There are clear rights and obligations of owner and builder in the Domestic Building Contracts Act 1995
There are clear contract based rights and obligations in the standard form building contracts drafted by the MBA or HIA. Sometimes builders don’t use these standard form contracts or they use a cost plus contract: this can become a lawyers picnic in the case of dispute!
Occasionally one of the professional consultants is at fault eg the soil tester, engineer, architect or draftsperson has made a mistake. The consultants owe a duty of care and are usually bound by contract to perform to the standard one would expect of a reasonably competent consultant in their profession.
Negligence and breach of contract claims are the standard claims at VCAT in the building list.