Almost every construction project runs into delays — bad weather, late variations, access problems, slow information. The question that decides who pays for them is whether the contractor is entitled to more time. Extension of time claims are how a builder or subcontractor formally seeks additional time to complete the work when a qualifying delay occurs, and getting them right protects you from liquidated damages you shouldn’t have to pay. Understanding how to make and manage extension of time claims is one of the more valuable commercial skills in construction.
This guide explains what extension of time claims are, why they matter, how to make them properly, and the common pitfalls — written in plain terms for Australian builders, subcontractors and trade contractors. It’s general information, not legal advice, so check your contract and seek advice on specific claims.
WHAT ARE EXTENSION OF TIME CLAIMS?
An extension of time claim is a formal request under a construction contract for more time to reach completion, made when a delay occurs that the contract recognises as entitling the contractor to extra time. If granted, it moves the date for completion, so the contractor isn’t in breach for finishing later than originally planned.
The key link is to liquidated damages. Most construction contracts let the principal charge liquidated damages for late completion, so a valid extension of time claim protects the contractor by adjusting the completion date and avoiding those charges for delays that weren’t their fault.
WHY THEY MATTER SO MUCH
The financial stakes are significant. Without a granted extension of time, finishing late can expose a contractor to liquidated damages — often a set amount per day — that add up fast on a delayed project. Extension of time claims are the mechanism that protects you from paying for delays outside your control.
There’s a second benefit too. On many contracts, an approved extension of time is also the gateway to claiming delay-related costs. So handling extension of time claims properly doesn’t just avoid damages; it can be essential to recovering the extra costs a delay imposes on you.
WHAT CAN JUSTIFY AN EXTENSION
What counts as a valid cause depends entirely on your contract, but commonly recognised delay events include:
- Inclement weather — beyond what could reasonably be expected.
- Variations — changes to the scope that add time.
- Late information or instructions — delays caused by the principal or superintendent.
- Access or site issues — being unable to get to or work on parts of the site.
- Latent conditions — unforeseen ground or site conditions.
Because entitlement is defined by the contract, the first step with any extension of time claim is always to check exactly what your contract lists as qualifying causes and what it requires of you.
HOW TO MAKE A CLAIM PROPERLY
1. Know your contract’s terms
Understand what causes qualify, what notice is required, and the timeframes. Every extension of time claim lives or dies by the contract’s specific requirements.
2. Give notice promptly
Notify the delay within the time the contract requires, which is often strict. Late notice is one of the most common reasons extension of time claims fail.
3. Document everything
Keep detailed records of the delay, its cause and its effect on the program. Good evidence is what makes an extension of time claim stand up.
4. Show the causal link
Demonstrate how the delay event actually affected completion, not just that it happened. The connection between cause and delay is what must be proven.
5. Follow the process exactly
Submit the claim in the form and within the timeframes the contract sets. Following the contractual process precisely protects your entitlement.
WHY NOTICE AND RECORDS WIN OR LOSE CLAIMS
If there’s one thing that determines whether extension of time claims succeed, it’s notice and documentation. Many contracts contain strict notice provisions — sometimes making timely notice a condition of entitlement — which means a genuine, well-founded delay claim can fail purely because the contractor didn’t notify it within the required window. Similarly, a claim with a real cause can collapse if the contractor can’t show, with contemporaneous records, that the event actually delayed completion. The lesson every experienced contractor learns, sometimes the hard way, is to notify early and document as you go: diarise delays, keep photos and correspondence, mark up the program, and record the effect on the critical path in real time rather than reconstructing it months later. The paperwork feels tedious in the moment, but it’s precisely what turns a valid grievance into a successful extension of time claim rather than an argument you lose.
COMMON EXTENSION OF TIME CLAIMS MISTAKES TO AVOID
- Missing the notice deadline. Late notice is a leading reason valid extension of time claims fail, as timely notice is often a condition.
- Poor records. Without contemporaneous evidence of cause and effect, even genuine claims struggle to stand up.
- Not proving the causal link. Showing an event happened isn’t enough; you must show it actually delayed completion.
- Ignoring the contract process. Failing to follow the required form and timeframes can forfeit an otherwise valid entitlement.
Getting the commercial side of construction right is core ACS Consulting territory. The Construction Estimation & Cost Consultancy service helps you understand and manage extension of time claims, delay costs and your contractual entitlements, while the Operations & Process Improvement service builds the notice and record-keeping habits that make claims stand up, and the SME Data Analysis & Power BI service tracks program and delay data. The free Perth SME Operational Audit Checklist helps you tighten your commercial processes. For authoritative guidance, Master Builders Australia, the Australian Government’s contracts and tenders resources, and Business Queensland on building payments are useful references. As this isn’t legal advice, check your specific contract and seek advice on individual claims.
FREQUENTLY ASKED QUESTIONS
What are extension of time claims?
Extension of time claims are formal requests under a construction contract for more time to reach completion, made when a delay occurs that the contract recognises as entitling the contractor to extra time. If granted, they move the completion date so the contractor isn’t in breach for finishing later.
Why do extension of time claims matter?
Because without a granted extension, finishing late can expose a contractor to liquidated damages — often a set amount per day — for delays outside their control. A valid extension of time claim adjusts the completion date to avoid those charges, and can also be the gateway to claiming delay costs.
What can justify an extension of time?
It depends on the contract, but commonly recognised causes include inclement weather beyond expectations, variations that add time, late information or instructions, access or site issues, and latent conditions. Always check exactly what your contract lists as qualifying delay events.
Why do extension of time claims often fail?
Most commonly because notice wasn’t given within the strict timeframe the contract requires, or because the contractor couldn’t show with records that the event actually delayed completion. Notifying early and documenting the cause and effect as you go are what make claims succeed.
CONCLUSION
Extension of time claims protect construction businesses from liquidated damages for delays outside their control, and can open the door to recovering delay costs. Know your contract’s terms, give notice promptly, document everything, prove the causal link, and follow the process exactly.
Because strict notice provisions and record-keeping so often decide the outcome, the disciplined contractor who notifies early and documents as they go turns extension of time claims from an argument into an entitlement. As this isn’t legal advice, check your contract and seek advice on specific claims.
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