Delay, EOT and Prolongation Claims
Delay is where contractors lose the most money they were entitled to keep. An extension of time protects you from liquidated damages; a prolongation claim protects your margin - and they are decided by different tests. This guide brings together CALIM's insights on extension of time, prolongation cost, concurrent delay, disruption, delay analysis methodology, and the contemporaneous records that decide whether a claim survives scrutiny.
Work through the articles below to build a complete picture of how time and money entitlements arise, how they are proven, and where most claims quietly fail on procedure rather than merit.
In this guide
Disruption vs Delay: Claiming for Lost Productivity
8 min readDelay AnalysisWhich Preliminaries and Time-Related Overheads Can You Recover?
8 min readDelay AnalysisHow to Calculate Prolongation Costs: Hudson, Emden and the Actual-Cost Approach
8 min readDelay AnalysisConcurrent Delay: How It Affects Your Time and Money Entitlement
8 min readDelay AnalysisDelay Analysis Methods Explained: As-Planned vs As-Built, Windows and Impacted Programmes
7 min readDelay AnalysisThe Contemporaneous Records That Make or Break a Delay Claim
7 min readEOT ClaimsWhat Is a Prolongation Claim - and What Actually Qualifies?
7 min readDelay AnalysisExcusable, Compensable, Non-Excusable: A Contractor's Map of Delay Types
8 min readEOT ClaimsEOT vs Prolongation: Why They're Not the Same Claim (and Why It Matters to Your Cash)
8 min readClaims DefenceClaims Consultant vs Lawyer: Who Do You Need, and When?
6 min readClaims DefenceWhy 80% of LD Claims Originate in Administration, Not Drafting
8 min readDelay AnalysisTime Impact vs. As-Planned vs. As-Built: Choosing the Right Methodology
10 min readClaims DefenceThe 28-Day Rule That Kills More Claims Than Any Dispute
3 min readEOT ClaimsWhy Do So Many EOT Claims Get Rejected?
5 min readReady to act on this?
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Frequently asked questions
What is the difference between an extension of time and a prolongation claim?
An extension of time (EOT) adjusts the completion date and protects the contractor from liquidated damages for a delay that was the employer's risk. A prolongation claim recovers the additional time-related cost of being on site longer. They are separate entitlements decided by separate tests, which is why a contractor can win the time but still fail to recover the money if the cost claim is not made and substantiated.
Why do so many valid delay claims get rejected?
Most rejected delay claims fail on procedure, not substance. The delay was real and the cost was incurred, but the notice was late, the cause-and-effect link was not demonstrated with contemporaneous records, or the wrong delay analysis method was applied to the available programme evidence. Disciplined notices and record-keeping from day one are what turn a legitimate delay into a recoverable entitlement.
How do I prove a construction delay claim?
A defensible delay claim needs a properly updated programme showing the critical path, timely notices of each delay event, and cause-specific contemporaneous records that let an analyst link the event to the critical delay. The choice of delay analysis method must fit the quality of the records. Reconstructed programmes carry far less evidential weight than contemporaneous ones, so the strength of a claim is largely fixed by the records kept while the work was live.
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