Practical completion. The date the rest of the contract turns on.
Practical completion is not handover, not the final invoice, and not the day the certifier signs. It is whatever your contract defines it to be — and a surprising number of building disputes are, underneath, an argument about which day it fell on.
In short
- Practical completion is defined by the contract, not by statute. Whether it has been reached is a question of fact measured against that definition.
- It typically starts the defects liability period, stops liquidated damages accruing, releases part of the retention or security, and opens the window for the final claim.
- Most definitions do not require perfection. Minor defects and omissions that do not prevent the works being used for their intended purpose usually do not stop practical completion being reached.
- The defects liability period is not a limitation period. Under section 18E of the Home Building Act 1989 (NSW) an owner has six years to commence proceedings for a breach resulting in a major defect and two years in any other case, both running from completion.
- During the period the builder generally has both the obligation and the right to return and rectify, so an owner who engages someone else without giving that opportunity may have difficulty recovering the cost.
Practical completion is the most consequential date in a building contract and one of the least precisely understood. Handover, the final invoice and the issue of an occupation certificate may each form part of the definition your contract uses, but none of them is the definition. There is no single statutory meaning: there is only what the contract says, and whether the facts on site answer it. We act for builders, contractors and developers, and this is what we most often unpick after handover.
What the date switches
The reason it is fought over is how much hangs off it. The detail varies between the HIA, MBA and ABIC families and between bespoke contracts, but the pattern is consistent.
| At practical completion | What usually happens |
|---|---|
| Defects liability period | Starts running |
| Liquidated damages | Stop accruing |
| Retention or security | A stated proportion is commonly released, the balance held to the end of the defects liability period |
| Care of the works and insurance | Commonly pass back to the principal or owner |
| Possession | The owner takes occupation of the site |
| Final payment claim | The contractual window for making it commonly opens — and, further down the clause, closes |
From the owner’s side the incentive is obvious: every day the date is said not to have been reached is another day of liquidated damages and another day the security stays put. From the builder’s side it runs the other way. That is why the certificate, not the defect list, is often the real dispute.
It is a question of fact, against the contract’s own words
Most standard definitions are built the same way: the works are complete except for minor defects and minor omissions that do not prevent them being used for their intended purpose; the tests the contract requires have been passed; and the documents, certificates and approvals it nominates have been delivered.
Two things follow. Practical completion does not require perfection: a list of items does not, by itself, mean the date has not been reached, and the argument is about whether those items are minor within the clause. And it is a question of fact about the works on a particular day, not a matter of anyone’s convenience.
Who decides, and what happens if they do not. Depending on the form, an architect or superintendent certifies practical completion, or the builder gives notice and the owner has a stated period to respond. Some forms fix the date as the day it was in fact achieved rather than the day certified; some deem it reached if no response comes in time.
“Practical completion” and “completion” are not the same word
For residential building work there is a second date to keep separate. The statutory warranties implied by the Home Building Act 1989 (NSW) run from completion of the work, and section 3B fixes what completion means for that purpose. It looks first to what the contract provides about when the work is complete; where the contract does not deal with it, the Act supplies its own tests.
The two dates may fall together, and may not. Treating them as interchangeable is how a limitation argument gets run from the wrong date, by either side. An occupation certificate, a creature of the planning legislation rather than of your contract, answers a third question again.
The defects liability period is not a limitation period
This is the most common misunderstanding on both sides of a handover. The defects liability period is a contractual mechanism: a window after practical completion in which defects are notified, the builder returns, and the works are brought to the contracted standard before the balance of the security is released. What it does not do is extinguish the owner’s rights when it expires.
A claim for breach of contract survives it, subject to the limitation periods in the Limitation Act 1969 (NSW), which run from when the cause of action accrues rather than from when a defect was noticed. So do the statutory warranties implied into every contract to do residential building work by the Home Building Act 1989 (NSW). Under section 18E an owner has six years to commence proceedings for a breach resulting in a major defect and two years in any other case, both running from completion — and where a breach becomes apparent in the last six months of a period, the Act allows a further six months after it ends. A builder told the matter is closed because the defects liability period has run should not rely on that.
Why the builder’s right to return matters so much
The clause is not only an obligation on the builder. It is generally a right as well: the right to be told about the defect, and the right to come back and fix it.
Where a builder is ready, willing and able to rectify at its own cost within the period, and the owner instead engages another contractor without giving that opportunity, the replacement cost may not be recoverable — the questions being whether the rectification work was necessary to produce conformity with the contract, whether it was a reasonable course to adopt, and whether the cost was reasonably incurred.
For residential building work the Act reinforces the position. Section 18BA imposes duties on the person with the benefit of a statutory warranty: to mitigate the loss, to make reasonable efforts to give written notice of a breach within six months after it becomes apparent, and to allow reasonable access to rectify. A failure to meet those duties can reduce what is recoverable. Section 48MA runs the same way, directing a court or tribunal deciding a building claim about defective residential building work to have regard to the principle that rectification by the responsible party is the preferred outcome.
None of that helps a builder who was told about a defect and did not attend. The right and the obligation come as a pair, and the paper trail proves which was exercised.
Running the period properly
- Give notice in the form and by the method the contract requires, and keep proof of when. An email that does not comply with the notice clause is not notice.
- Diarise the date the period ends, and the security release with it.
- Answer every defect notice in writing, including those you dispute, and offer access dates. A refusal to attend is worth more to the other side than the item itself.
- Photograph and date rectification work, and check whether the contract starts a fresh period for rectified items.
- Ask for a joint inspection before the period closes rather than letting the date pass quietly.
These arguments arrive alongside liquidated damages and retention, because the same date drives all three. Our page on building contract disputes covers the delay side, and defending defect claims covers how a defect schedule is tested once it becomes a claim.
Questions builders ask us after handover.
The owner refuses to certify practical completion over a punch list. Can they do that?
Not if the outstanding items fall within the contract’s own carve-out. Most definitions allow minor defects and minor omissions that do not prevent the works being used for their intended purpose, so the argument is about whether these items are minor within that clause — not whether a list exists. Whether the form allows the date to be taken as reached if the owner does not respond in time is the next question, and that depends on the contract in front of you.
Does the defects liability period limit how long we can be sued?
No. It is a contractual window in which defects are notified and rectified before the security is released, and it does not extinguish the owner’s rights when it ends. For residential building work, section 18E of the Home Building Act 1989 (NSW) gives an owner six years to commence proceedings for a breach resulting in a major defect and two years in any other case, both running from completion — periods usually far longer than a defects liability period.
The owner brought in another builder to fix our work and sent us the invoice. Do we have to pay it?
Not automatically. Where the contract gave you the right to return and rectify and you were ready and able to do so, the questions become whether the owner allowed reasonable access, whether the rectification work was necessary and a reasonable course to adopt, and whether the cost was reasonably incurred. For residential work, section 18BA of the Home Building Act 1989 (NSW) also imposes notice, access and mitigation duties on the person with the benefit of the warranty.
Does the defects liability period start again for items we have rectified?
Sometimes. A number of standard forms provide a further period running from the date rectification work is completed, either for the rectified item alone or more broadly. It is a clause to read rather than assume, because it determines when the balance of the security is actually releasable and how long your exposure on that item runs. It is also worth checking whether that further period is capped.
Tell us what's happened.
If practical completion is in dispute, or a rectification demand has arrived after handover, tell us what the contract says and which date is being argued about.
Information on this site is general in nature and is not legal advice, and may have been overtaken by a change in the law. Contacting us does not create a solicitor–client relationship.