What Is a Defects Liability Period (DLP)?
A defects liability period (DLP) is a fixed period of time, starting at practical completion, during which the contractor is contractually obliged to return to the site and rectify any defects that appear in the completed works, at their own cost. It gives the client a formal mechanism to have faults fixed before the job is fully closed out, and it is commonly around 12 months on commercial contracts and shorter on residential jobs, though the exact length is always set by the specific contract.
Key takeaways
- A defects liability period (DLP) is the contractual window after practical completion in which the contractor must rectify defects in the works at their own cost.
- It typically runs 12 months on commercial contracts such as AS4000 and AS2124, and often a shorter period — commonly around 13 weeks — on residential building contracts.
- The DLP starts at practical completion and ends at final completion, once the defects identified during the period have been made good.
- The balance of retention withheld during construction is usually released only at the end of the DLP, which gives the client real leverage to get defects fixed.
- A DLP is not the same as a statutory warranty period — statutory warranties on residential building work typically run much longer and exist independently of the contract.
What is a defects liability period?
A defects liability period is the block of time, defined in the construction contract and starting at practical completion, during which the contractor remains responsible for returning to site and rectifying any defects that show up in the completed works — at no extra cost to the client. It exists because practical completion is reached once the works are fit for their intended use, minor defects aside, so the contract needs a mechanism to deal with exactly those minor defects and anything else that only becomes apparent once the building is actually being used.
The DLP is not a warranty in the general legal sense and it is not the only protection a client has — it is a specific contractual obligation, set out in the contract itself, that gives the contractor both a right and a duty to fix its own defective work within a defined window, rather than leaving the client to arrange and pay for repairs and chase reimbursement afterwards.
Nearly every standard form building contract used in Australia includes a defects liability period clause, though the label varies — some contracts call it a "maintenance period" instead, and the two terms are generally used to mean the same thing.
In plain terms
A defects liability period is the builder’s "come back and fix it" window — the agreed stretch of time after the job is handed over during which any faults that show up are the builder’s job to repair, not a fresh bill for the client.
What happens during the defects liability period
The DLP typically opens with a defects list — often called a snag list — compiled jointly, or by the superintendent, at the practical completion inspection. That list captures the minor items that were outstanding when PC was certified, and it becomes the contractor’s first job during the DLP.
From there, the period is mostly about notice and rectification: further defects that appear as the client actually uses the building are notified to the contractor, who is given a reasonable opportunity to inspect and repair them before the DLP ends.
- An initial defects list agreed at, or shortly after, the practical completion inspection.
- Further defects notified in writing by the client or superintendent as they are discovered during use.
- The contractor inspecting and rectifying notified defects within the timeframe the contract allows.
- A final inspection near the end of the DLP to confirm all notified defects have been properly made good.
How long does a defects liability period last?
There is no single standard length — the DLP is whatever the specific contract says it is, and it varies noticeably between commercial and residential work. Commercial contracts tend to run a longer DLP, reflecting the scale, complexity and cost of the works, while residential contracts are usually shorter because the works are smaller and issues tend to surface faster.
The figures below are typical starting points seen in common Australian contract forms, not a universal rule — always confirm the actual clause in your contract rather than assuming a standard period applies.
| Contract type | Typical DLP length | Starts at | Ends at |
|---|---|---|---|
| AS4000 (commercial) | 12 months | Practical completion | Final completion |
| AS2124 (commercial) | 12 months | Practical completion | Final completion |
| HIA / Master Builders (residential) | Around 13 weeks | Practical completion | Final completion |
When the DLP starts and ends
The defects liability period begins on the date practical completion is certified — which is exactly why disputes about the actual PC date matter so much, since the DLP clock (and, separately, liquidated damages) both run from that single date. If PC is delayed or backdated, the whole DLP timeline shifts with it.
The DLP ends at final completion, once the defects notified during the period have been rectified to the standard the contract requires and any final inspection has been signed off. Final completion is a separate, later milestone from practical completion, and it is the point at which the contract is effectively closed out and the last of the retention is due for release.
The defects liability period and retention
The DLP and retention are closely linked in most Australian contracts. A common structure releases part of the retention — often around half — at practical completion, with the remaining balance held until the end of the defects liability period, once outstanding defects have been made good.
That structure gives the client real leverage: if the contractor is slow to rectify defects, the client can hold the remaining retention until the work is actually done. Conversely, if the contractor fails to rectify a defect within a reasonable time after notice, many contracts allow the client to have the defect fixed by someone else and deduct the cost from the retention held.
Who is responsible during the defects liability period
The contractor is responsible for rectifying defects in its own work at its own cost during the DLP — that obligation is the whole point of the period. The client or superintendent is responsible for giving the contractor proper notice of defects, allowing reasonable access to inspect and fix them, and not unreasonably obstructing rectification.
It is also worth noting what the DLP does not cover: damage caused by the client’s own use, fair wear and tear, or work by other parties engaged after handover are generally not the contractor’s responsibility to fix, even if the damage surfaces during the DLP. Distinguishing a genuine defect from ordinary wear or client-caused damage is a common point of friction near the end of a project.
Defects liability period vs other terms
A handful of related terms get used loosely around the end of a project, but each one means something distinct:
- DLP vs retention — the DLP is the timeframe during which defects must be rectified; retention is the money withheld as financial security over roughly that same period.
- DLP vs statutory warranty period — a DLP is a contractual obligation set by the specific contract; statutory warranties on residential building work exist independently under state legislation and typically run for a much longer period, regardless of what the contract itself says.
- DLP vs practical completion — practical completion is the milestone that starts the DLP; the DLP is the period that follows it, not the milestone itself.
- DLP vs maintenance period — some contracts, particularly those following international forms, use "maintenance period" as another name for essentially the same concept.
Common mistakes with the defects liability period
Most DLP disputes and missed rights trace back to a small number of avoidable mistakes:
- Not properly documenting the defects list at practical completion, leading to later arguments about what was actually outstanding.
- Missing the end of the DLP without inspecting and formally closing it out, so retention sits unclaimed longer than it needs to.
- Treating the DLP as a general warranty and expecting the contractor to fix damage that is really wear and tear or the client’s own doing.
- Failing to give the contractor proper written notice of a defect, which can complicate any later attempt to have it fixed by someone else and deducted from retention.
- Assuming the DLP length is a fixed industry standard rather than checking the actual figure in the contract.
How My Trade Hub helps around the defects liability period
My Trade Hub keeps the scope of works, priced Bill of Quantities and progress claim history for a project linked together from the original tender right through to close-out, so when practical completion and the DLP arrive, there is already a clear, itemised record of exactly what was contracted, built and claimed.
That means the defects list, retention reconciliation and final account can be pulled together from real project data rather than reconstructed from memory or scattered paperwork — making the handover into the defects liability period, and the final claim at the end of it, considerably less stressful for everyone involved.
Frequently asked questions
What is a defects liability period in simple terms?
A defects liability period (DLP) is the set window of time after a building is handed over during which the builder must come back and fix, at their own cost, any defects that show up in the work. It usually runs from practical completion to final completion.
How long is a defects liability period?
It depends entirely on the contract. Commercial contracts such as AS4000 commonly run a 12-month DLP, while residential contracts often run a shorter period, such as around 13 weeks. Always check the actual clause in your contract rather than assuming a standard length.
What is the difference between a DLP and retention?
The defects liability period is the timeframe during which defects must be rectified. Retention is the money withheld from progress payments as financial security over roughly that same period, with the final balance commonly released at the end of the DLP.
Who pays for defects found during the defects liability period?
The contractor is responsible for rectifying, at their own cost, defects in their own work identified during the DLP. Damage caused by the client’s own use, fair wear and tear, or work by other parties engaged after handover generally falls outside the contractor’s DLP obligations.
What happens if defects are not fixed during the DLP?
If a contractor fails to rectify a properly notified defect within a reasonable time, many contracts allow the client to have the work done by someone else and deduct the cost from the retention held, rather than waiting indefinitely.
Is a defects liability period the same as a warranty?
Not quite. A DLP is a specific contractual obligation set by the particular contract. Statutory warranties on residential building work exist separately under state legislation and typically run for a longer period, regardless of what the DLP clause in the contract says.
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