Extension of Time Claims Explained

What Is an Extension of Time?

An extension of time (EOT) is an adjustment to the contractual completion date to reflect delay that is not the contractor's responsibility. Its primary purpose is to relieve the contractor of liability for liquidated damages for the period of excusable delay. Under NEC contracts, time is adjusted through the compensation event mechanism; under other forms it is claimed through the relevant extension of time provisions, usually with strict notice requirements.

Time and Money Are Linked but Distinct

An extension of time deals with time - it moves the completion date. Whether the contractor also recovers the cost of being on site longer (prolongation) depends on the cause of the delay and the contract provisions. The two are linked but must be argued separately: an EOT does not automatically bring cost, and a cost claim without the delay analysis to support it is exposed. The strongest claims present both together.

What Makes an EOT Claim Succeed

Successful extension of time claims share three features. First, a clear contractual basis - the specific clause or compensation event relied upon. Second, compliance with notice requirements, because late notice can reduce or extinguish entitlement. Third, and most important, robust delay analysis demonstrating that the delay event affected the critical path and pushed out completion. Without that causal link, an EOT claim is merely an assertion.

The Role of the Critical Path

Only delay to the critical path delays completion. A delay event affecting work that has float may cause local disruption without extending the project. This is why forensic planning sits at the heart of every credible EOT claim - it isolates the critical path, shows how it moved, and links the delay event to the completion date. It is also why concurrency is so frequently disputed.

Common Reasons Claims Fail

Extension of time claims most often fail through late or absent notice, inadequate records, reliance on assertion rather than analysis, or failure to demonstrate critical path impact. Each of these is avoidable with disciplined contract administration and a properly constructed analysis built on contemporaneous evidence.

How Projjex Helps

Projjex prepares and substantiates extension of time and prolongation claims on NEC, JCT and IChemE projects - combining forensic delay analysis with defined cost quantum to present time and money together. This integrated approach has delivered multi-million pound EOT claims across the UK water sector. Get in touch to discuss your claim.