Walter Lilly & Company Ltd v Mackay and DMW Developments [2012] EWHC 1773 (TCC)  

We discussed this case back in July (Issue 145). In the course of his judgment Mr. Justice Akenhead made a number of interesting comments about the approach to the expert evidence. In terms of the delay evidence, he preferred the approach of establishing critical delay by reference to the “logical sequence(s) of events which marked the longest path through the project”. This was both “logical and conventional”.  

Regard should be had to the likely longest sequence of the outstanding work on a monthly basis as being the primary pointer to what was delaying the work at any one time. This the Judge thought was a wholly logical approach and, indeed is the approach used by most delay experts when there is a usable baseline programme from which to work. The logic, explained the Judge, is simply that if there are, say, two outstanding items of work, A and B, and A is always going to take 20 weeks to complete but B is only going to take 10 weeks, it is A which is delaying the work because B is going to fi nish earlier; overall completion is therefore dictated by the length of time needed for A. Put another way, it does not matter if B takes 19 weeks, it will be the completion of A that has prevented completion. Thus, if one is seeking to ascertain what is delaying a contractor at any one time, one should generally have regard to the item of work with the longest sequence. Therefore it is necessary to have regard to how long individual items actually took to perform and not just to how long one party or the other at the time was saying it would take.  

The Judge was also clear that what an expert cannot do is to prepare a report that simply says that the “other side” has not proved its case. He stressed that: “it is not for an expert to suggest this type of thing.” Further the adoption of an approach based on determining the most “signifi cant” matters preventing practical completion is not helpful as it tends to refl ect a subjective approach as to what a client thought was signifi cant.  

In the delay assessment exercise the court should be very cautious about giving signifi cant weight to the supposedly contemporaneous views of persons who did not give evidence. Without testing the evidence, it is unclear whether the relevant person who made that particular statement had undertaken any analysis or had considered all the matters that had been put in issue in the proceedings or even whether they have given an informed view.

There was also discussion of snagging. In the assessment of which events caused what overall or critical delay, one should remember that it is not necessarily the last item or the area of work that is finished last which causes delay. Often on building projects, the last item of work is the fi nal clean up of the site, something that may only take a short time. However, it is the task which takes longer than anticipated and so delays the fi nal operation that must be assessed. There will always be minor defi ciencies or incomplete items of work which will be required to be completed before handover.  

If there is an excessive amount of snagging and therefore more time than would otherwise have been reasonably necessary to perform the de-snagging exercise has to be expended, it can potentially be a cause of delay in itself.  

There was some disagreement between the experts as to what “Practical Completion” meant. The Judge noted that it means completion for all practical purposes and what that completion entails must depend upon the nature, scope and contractual defi nitions of the Works, as they may have developed by way of variation or architect’s instructions. There was common ground between the experts that de minimis snagging should not be a bar to Practical Completion unless there is so much of it that the building in question cannot be used for its intended purposes.  

Whilst it may not seem unreasonable to pose the question: “what were the most signifi cant matters which, at any given time, were preventing practical completion from being achieved?”, this could lead to a subjective approach. Further, it was not the case that just because works are finished before Practical Completion they cannot have delayed completion.