Parts 1 and 2 dealt with the FIDIC 1999 Sub-Clause 20.1 notification clock and what happens when the window is missed. Part 3 turns to the substantive question that often follows. The Employer’s breach has caused a critical delay; the Contractor has also slipped, but its slippage runs inside the Employer’s window and does not push completion any further. Can the Employer recover liquidated damages on the Contractor’s portion, set off any part of the prolongation, or terminate on the Contractor’s slippage as a fundamental breach?
The common-law construction-arbitration practitioner reaches for North Midland Building Ltd v Cyden Homes Ltd [2018] EWCA Civ 1744 and the Society of Construction Law Protocol on delay and disruption. Both confirm, in their respective ways, that the analysis turns on causation, not on the mere existence of an overlap. The harder question, in a Finnish-law forum, is whether the same answer follows. Möller’s view is unambiguous: under Finnish law the claimant must prove a causal link between the alleged breach and the loss; without one, no liability follows.
The architecture of the answer turns on a single distinction: the calendar overlap of two delays, and the causal contribution each delay actually made to the completion date. In the hypothetical, the Employer’s dominant critical delay shifts the completion date out by one hundred days. The Contractor’s parallel slippage of twenty-five days runs entirely inside that window. If the Contractor’s slippage were stripped out, the completion date would still be at the same point because the Employer’s delay had already pushed it there. The Contractor’s slippage occupies time on the printout but does not add a single day to the project.
The common-law position is settled. In North Midland Building Ltd v Cyden Homes Ltd [2018] EWCA Civ 1744 the Court of Appeal upheld a contractually agreed concurrent-delay regime; outside any such bespoke regime the orthodox position remains that the analysis turns on causation. The Society of Construction Law Protocol on delay and disruption operates to the same effect: a Contractor’s parallel slippage that does not extend the completion date does not, on its own, generate liability. The harder question, again, is whether the same answer follows in a forum that has not absorbed those English-law authorities directly.
The case-study application in this matter is instructive. The Contractor delayed the start of an early excavation activity. The activity was on the contractual programme but was not driving completion at the relevant moment, because the Employer’s late design had pushed the dominant critical path elsewhere. The Contractor’s deferral was, in the language of the day, a mitigation: standing labour and idle plant cost the Contractor money, and deferring the activity reduced that cost. The Contractor sought no relief for the deferral itself, made no change-order request, and claimed no extension of time for it. The question put to Möller was whether the Employer could nonetheless reach for it as a basis to recover liquidated damages, set off the prolongation, or terminate on the back of it.
Under Finnish law the claimant has to prove that there is a causal link between the alleged breach and the damage or loss which the claimant contends results from the breach. Since the Contractor’s parallel slippage does not have any impact on the delayed project completion date, and thus did not cause any further delay, there is no causal link between the Contractor’s slippage and that date. There is no liability for the Contractor on the parallel delay.
The same reasoning applies on the Employer’s ability to terminate. Where the Contractor’s slippage did not have any impact on the delayed completion caused by the Employer’s own dominant critical delay, the Employer cannot use the Contractor’s slippage as a basis to terminate the contract. Raj’s causal-link framework, anchored in North Midland and the Society of Construction Law Protocol, is consistent with Finnish law on the same point.

