Case Summary: Thomas Barnes & Sons Plc v Blackburn with Darwen Borough Council [2022] EWHC 2598 (TCC)

Ava Solouk and Dr Julian Critchlow

delay analysis


This case considered, amongst other things, how to determine an appropriate delay analysis method and how concurrent delay should be taken into account in construction disputes.


The Court indicated that there is no one size fits all approach to delay analysis and that the choice of method will depend on the facts and circumstances of each case. It acknowledged the various methods that are commonly used in delay analysis, such as the critical path method (CPM), time impact analysis (TIA), and collapsed as-built analysis (CAA), and noted that each method has its own advantages and disadvantages.


The Court emphasized the importance of ensuring that the chosen method is appropriate and reliable, and that the analysis is carried out by a qualified and experienced delay expert. It also acknowledged that delay analysis should be viewed as a tool to assist in understanding the causes and effects of delay, rather than as a means of apportioning blame.


With regard to concurrent delay, the Court’s view was that it is a situation in which two or more events occur at the same time, each of which would independently cause delay to the project. It recognized that concurrent delay is a common occurrence in construction projects and that it can be difficult to apportion responsibility for delay when it occurs.


The Court said that there are two possible approaches to dealing with concurrent delay. The first, the "but for" test, requires consideration of what delay would have occurred if the concurrent event had not occurred. The second, the "apportionment" approach, requires the court to apportion responsibility for the delay between the parties based on their respective contributions to the delay.


The Court said that both approaches have their advantages and disadvantages and that the choice will depend on the facts and circumstances of each case. The importance of ensuring that any apportionment of delay is fair and reasonable was emphasized, taking into account the respective contributions of the parties.


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