Building contract

The legal agreement between a homeowner and a builder for residential construction work. Most Australian residential builds use a standard contract template from HIA or MBA, modified for the specific build.

Definition

A building contract is the legal agreement between a homeowner and a builder that sets out the scope of work, the contract price, the payment schedule, the timeline, the inclusions and exclusions, the rights and obligations of each party, and the procedures for handling variations, defects, and disputes. Most Australian residential building contracts use a standard template, modified for the specific build.

Why it matters

The building contract is the document that determines what happens at every stage of the project. Disputes that go to the relevant state tribunal almost always turn on contract interpretation. The contract sets the percentages of each progress payment, the conditions for practical completion, the defects liability period, the variation procedures, and the legal remedies available to each party. Owners who haven't read their contract carefully are operating under terms they didn't fully consent to.

How it works in practice

The two main standard contract bodies in Australian residential construction are the Housing Industry Association (HIA) and Master Builders Australia (MBA). Each publishes standard residential building contracts that builders typically use. Each state may have its own variants of these standard contracts, or its own state-specific standard contracts.

The contract is signed before construction begins and forms the legal basis of the relationship for the duration of the build and the defects liability period afterward. Modifications to the standard contract (called amendments or special conditions) are common and can significantly change the parties' rights.

Independent legal review of a building contract before signing is strongly recommended. The cost is small relative to the contract value, and contract review by a construction lawyer can identify problematic clauses, clarify ambiguous terms, and negotiate better positions on key issues like variations, retention, and dispute resolution.

Common misconceptions

Standard contracts are fair

They're standardised, not necessarily fair to either party. HIA contracts have been criticised for favouring builders. MBA contracts have similar concerns. Either way, the standard form is a starting point, not a fairness guarantee.

Once signed, the contract can't be changed

Variations are changes during the build. The original contract terms are usually fixed once signed, but variations can substantially change the practical terms over time.

The contract price is the final price

It isn't, usually. PC sums, provisional sums, and variations all contribute to a final price that's almost always different from the contract price at signing.