Construction Law FAQ

The main families are the AS series (AS 4000, AS 2124, AS 4902, AS 4300), the ABIC forms for architect-administered residential and commercial work, the GC21 for NSW government, and the NEC4 suite for larger infrastructure projects. Each allocates risk differently.

Security of payment is a statutory regime in each Australian state and territory giving contractors and subcontractors a fast-track right to recover progress payments through adjudication, with limited defences available to the respondent.

SOPA adjudication is deliberately fast. From the payment claim to determination is typically 4-6 weeks, with tight deadlines for payment schedules, adjudication applications, and responses. Missing a deadline can be fatal to a party's position.

A payment claim is a written claim for a progress payment under SOPA that identifies the construction work, the claimed amount, and states it is made under the Act. Form and content requirements vary slightly between states.

A payment schedule is the respondent's reply to a payment claim identifying the amount they propose to pay and reasons for withholding. Failure to serve a payment schedule within the statutory period can create a debt due for the full claimed amount.

SOPA determinations can be challenged only on limited grounds — essentially jurisdictional error or denial of natural justice. Judicial review is to the Supreme Court. The courts have repeatedly emphasised the "pay now, argue later" purpose of the regime.

A variation is a change to the scope of work ordered under the contract. It must usually be in writing and follow the contract's notice and pricing procedures. Undocumented variations are a common source of disputes, with recovery depending on the contract terms and quantum meruit.

An EOT is an extension of the contractual date for practical completion where a qualifying delay occurs. The contract sets out the procedure, notice requirements, and causes that qualify. Failure to notify within contractual timeframes can waive the right to claim.

Liquidated damages are pre-estimated sums payable by the contractor for delay beyond practical completion. They must represent a genuine pre-estimate of the principal's likely loss, otherwise they may be unenforceable as a penalty.

Practical completion is the stage when the works are complete except for minor defects that do not prevent the principal from using the works for their intended purpose. It triggers handover, release of retention or bank guarantees, and the start of the defects liability period.

The defects liability period is the period after practical completion during which the contractor is obliged to rectify defects notified by the principal. It does not extinguish rights for defects discovered after the period — those can still be pursued as damages for breach.

The general limitation period for breach of contract is 6 years, and for tort is 6 years from damage. Statutory warranty regimes (such as Part 2C of the Home Building Act in NSW) have their own limits — 6 years for major defects, 2 years for minor defects.

Most states imply statutory warranties into residential building contracts covering workmanship, materials, compliance with plans and laws, fitness for purpose, and completion within time. These warranties benefit the owner and subsequent purchasers.

Home building compensation (previously home warranty insurance) is a statutory insurance scheme in most states protecting owners against incomplete or defective work where the builder has died, disappeared, become insolvent, or had their licence suspended. It applies to contracts above a threshold.

The superintendent administers the contract and exercises discretions such as certification of payments, assessing EOTs, and valuing variations. Under Australian case law the superintendent must act honestly and fairly when certifying, even though appointed by the principal.

A bank guarantee is an unconditional undertaking from a bank to pay a specified amount on demand, provided as performance security. The courts generally uphold the autonomy principle — unless the call is fraudulent or unconscionable, the bank must pay despite underlying disputes.

A prolongation claim seeks the actual costs of the contractor being on site for longer than planned due to delays for which the principal is responsible. It covers site overheads, supervision, and plant costs, separate from any EOT entitlement.

Construction disputes are commonly resolved through SOPA adjudication (progress payments), expert determination, mediation, arbitration (especially for larger projects), or litigation in the Supreme Court or a specialist tribunal like NCAT. Contracts often mandate a tiered DR process.

Following the Lacrosse fire and Grenfell Tower, Australian states have introduced regimes requiring the identification, assessment, and rectification of combustible cladding on buildings, with significant liability exposure for builders, certifiers, and consultants.

SOPA adjudications typically cost $5,000-$50,000 per party. Small commercial disputes often cost $50,000-$250,000. Major arbitrations and litigated matters routinely run into millions — a significant driver of settlement at mediation.