Concurrent Delay Case Review: Thomas Barnes & Sons PLC v Blackburn with Darwen Borough Council

The Council engaged Thomas Barnes to build a new bus terminal in Blackburn, UK.

After significant cost and time overruns, Thomas Barnes sought extensions of time and prolongation costs. The Council rejected the claims, terminated Thomas Barnes for delay, and engaged others to complete the works.  

Thomas Barnes (in administration) sued for payment and damages, relying on expert delay analysis to support a 172day EOT. the Council denied liability. 

Two delays were in issue:  

1. Council-responsible steelwork deflection investigations/remedial works affecting critical path activities (steel deflection delay) 

2. Thomas Barnes caused a delay to roof covering works (roof covering delay). The Council argued the roof covering delay was concurrent with the steel deflection delay. 

Expert delay evidence

Each party relied on expert delay evidence drawing on the Society of Construction Law’s Delay and Disruption Protocol. Thomas Barnes used an as-planned v as-built window analysis, whilst the Council used a time-slice window analysis and time impact analysis. 

The judge emphasised that methodology is secondary to common sense: the Court is not confined to choosing between experts and must decide, as a matter of fact, what delayed the works and for how long. 

Given the divergence in the expert evidence, the court reached its own view on concurrency between the steel deflection delay and roof covering delay. A similar approach was taken by the Court in see White Constructions v PBS Holdings [2019]. 

Concurrent delay

“True” concurrent delay requires that: 

1. Two delay events occur at the same time 

2. The effect (delay to the project) of those two events is experienced at the same time. 

True concurrent delay is rare (see Adyard Abu Dhabi v SD Marine Services [2011]).  

Another approach to assessing concurrent delay is the “first in time” method. The “first in time” concurrent delay analysis approach determines that when two delays overlap, the delay that started first “controls” the outcome during the overlap period.  

If a first in time analysis was applied in this matter, the roof covering delay would not be concurrent because it started later and could not affect the critical path i.e., the earlier steel deflection delay created “float” in the roof covering sequence of activities. 

Decision

The Court held the delays were concurrent, even though the roof covering delay was resolved while the steel deflection delay continued. 

In summary, both the remedial steelwork and completion of the roof coverings were required before the hub finishes could properly commence. Each delay dictated the critical path for their respective stage, causing delay over the same period. 

The court granted Thomas Barnes a 119day EOT for the steel deflection delay but awarded prolongation costs only for the non-concurrent portion of that delay (27 days). 

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Key Takeaways

The reasoning effectively rejects the “first in time” approach to concurrent delay. While supported by older authorities, it departs from some more recent cases and industry guidance and is likely to be debated. 

The court did not adopt either party’s expert analysis and instead applied an “effective cause” assessment, where the court likewise rejected both analyses and appointed its own expert. 

Overall, the decision supports parties resisting “first in time” concurrency arguments and reinforces a pragmatic, fact-driven approach to delay and signals a trend in Australia and the UK toward pragmatic, court-led delay assessment rather than wholesale adoption of expert analysis. 

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