Understanding your NSW building contract

A building contract serves as a legally binding agreement between homeowners and builders, outlining the terms and conditions for a construction project. Reading and understanding your contract thoroughly is crucial to identify key provisions related to progress payments and variations.

What to do when your builder issues a non-compliant invoice

A non-compliant invoice under NSW law is one that does not adhere to the terms outlined in the building contract. When faced with a non-compliant invoice, homeowners should:

  1. Review the building contract to identify discrepancies between the invoice and the agreed-upon terms.
  2. Communicate with the builder to address any discrepancies and seek clarification or amendments.
  3. Maintain accurate records of all correspondence and invoices to support any potential disputes.

Legal principles related to waiver and repudiation

Waiver and repudiation are two legal concepts relevant to building contracts. Waiver occurs when a party voluntarily abandons their contractual rights, while repudiation refers to a party’s refusal to perform their contractual obligations. Relevant cases include Petropoulos, Expense Reduction Analysts Group Pty Ltd v Armstrong Strategic Marketing Pty Ltd, and DB Homes Australia Pty Ltd v Kes. These cases illustrate the importance of understanding and asserting contractual rights when dealing with non-compliant invoices.

Quantum meruit claims

Quantum meruit is a legal principle that allows a party to recover a reasonable sum for services rendered in the absence of a binding contract. Relevant cases include Pavey & Matthews Pty Ltd v Paul and Goodacre v Trinder Alpine Constructions Pty Ltd. Homeowners disputing a non-compliant invoice may face a quantum meruit claim if the builder argues that they are entitled to payment for work completed. Understanding these legal principles can help homeowners navigate potential disputes.


When faced with a non-compliant invoice, homeowners should carefully review their building contract, communicate with the builder, and maintain accurate records. It is essential to understand the legal principles of waiver, repudiation, and quantum meruit to protect one’s interests. Homeowners are encouraged to seek legal advice if they have concerns about their building contract or invoices issued by their builder.