The Technology and Construction Court’s decision in MJS Projects (March) Limited v RPS Consulting Services Limited [2026] EWHC 884 (TCC) addresses whether a successful defendant’s conduct in refusing mediation and its expert’s late change of evidence justified departing from the usual costs rule.
Background
This costs judgment arose from the dismissal of a professional negligence claim brought by MJS Projects (March) Limited against RPS Consulting Services Limited in the Technology and Construction Court in Leeds. The underlying dispute concerned the design and construction of a container park near Felixstowe Port, with the Claimant alleging that the Defendant’s design fell below the standard of a reasonably competent firm of civil and structural engineers. The court ultimately found in favour of the Defendant, concluding that the cause of the damage was workmanship rather than design.
The pre-action history was protracted. The Defendant’s letter of response, dated 22 May 2019, set out in considerable detail why it considered its design was not negligent and identified eleven workmanship defects, as well as the use of incorrect dowel sizes. The Claimant’s response, dated 5 November 2019, did not engage with those workmanship allegations and instead requested sight of the Defendant’s calculations. Those calculations were provided by letter dated 22 December 2020. No substantive reply was received for nineteen months. When the Claimant wrote again in July 2022, it confirmed that an expert structural engineer had been instructed and that the expert supported the Claimant’s position on design negligence. Proceedings were issued on 14 October 2022. Particulars of Claim were served on or around 10 February 2023, a Defence on or around 14 April 2023, and a Reply on 19 May 2023.
The expert evidence timetable was, as the court described it, “concertina-ed” into a short period before trial. The experts’ joint statement was produced approximately three months before trial, with individual expert reports following thereafter. Supplementary reports were filed in response to points raised in the primary reports, with some material served as late as one week before the trial commenced in February 2024. The claim was dismissed following trial, and the costs and consequential orders hearing took place on 14 May 2025, with judgment handed down on 15 April 2026.
Costs Issues Before the Court
Three distinct costs issues required determination. The first was whether the usual costs order, namely that the unsuccessful Claimant pay the Defendant’s costs, should be departed from on account of the Defendant’s conduct in relation to alternative dispute resolution. The Claimant argued that the Defendant had unreasonably refused to engage in mediation on multiple occasions, both before and after proceedings were issued, and that this conduct justified a departure from the default position under CPR 44.2. The Claimant’s position was that the appropriate order was no order as to costs.
The second issue was whether the Defendant’s expert having changed his position on the mass concrete taper and having produced additional calculations approximately one week before trial constituted conduct that should further influence the costs order in the Claimant’s favour.
The third issue was the Defendant’s cross-application for indemnity costs in respect of the expert evidence phase of the proceedings. The Defendant contended that the conduct of the Claimant and its legal team in relation to the instruction, oversight, and management of the Claimant’s expert was sufficiently outside the norm to justify an order for costs on the indemnity basis for that phase. In the alternative, both parties agreed that a payment on account of costs should be made, with the only dispute being the appropriate percentage reduction to apply to the approved costs budget.
The Parties’ Positions
The Claimant’s position on ADR
The Claimant traced a series of proposals for mediation made from as early as 14 July 2022, when a without prejudice meeting, mediation, or meeting of experts was suggested. That proposal was declined by the Defendant on 30 September 2022 on the basis that mediation was not appropriate until the Claimant had provided its expert report. Further proposals were made on 5 June 2023 and 21 September 2023, the latter suggesting two named mediators and a mediation in late October or November 2023. The Defendant declined that proposal by letter dated 28 September 2023, citing the technical nature of the issues and the fact that liability was denied in full, and suggesting that any mediation should follow the experts’ joint statements due in November 2023.
The Claimant characterised the Defendant’s successive objections as a shifting of the goalposts: first, no mediation until the expert report was provided; then, no mediation until after expert discussions; then, no mediation without the experts present at the mediation itself. The Claimant noted that its expert was based in Singapore, making expert attendance at a mediation impractical. It submitted that, applying the Halsey v Milton Keynes General NHS Trust [2004] 1 WLR 3002 factors, this was not a case unsuitable for mediation. Professional negligence disputes of this nature were routinely resolved at mediation, the parties’ budgets had each included approximately £25,000 for mediation costs, and the value of the claim at nearly £400,000 justified that expenditure. The Claimant also submitted that the merits were not entirely one-sided, given that the Defendant’s expert had changed his position on the mass concrete taper and that the outcome might have been different but for the late additional calculations.
The Claimant’s position on the expert’s late change of evidence
The Claimant submitted that the Defendant’s expert had stated in his written evidence that the mass concrete taper was part of the design and that the failure to install it was a workmanship defect causing the cracking. At trial, he accepted that the mass concrete taper was not part of the design at the relevant joints. The Claimant argued that it had been entitled to approach trial on the basis that the Defendant’s expert would give evidence consistent with his written report and the joint statement. The Claimant asserted that the expert changed his mind as a result of very late additional calculations produced one week before trial, and that this late change of position had a decisive impact on the outcome. On that basis, it was submitted that it would be unjust for the Defendant to recover all of its costs.
The Claimant’s position on indemnity costs
The Claimant resisted the indemnity costs application on the basis that the threshold was high and had not been met. It submitted that the correct Bolam question had in fact been put to the expert in his letter of instruction and was set out on the face of his report. The fact that the expert appeared under cross-examination not to have applied the test correctly did not amount to conduct unreasonable to a high degree. The Claimant also relied on the compressed expert evidence timetable, noting that reports were served late and that supplementary reports followed in quick succession. It was submitted that the expert’s decision to rerun the FE analysis immediately before trial, without informing anyone, could not be attributed to the Claimant or its lawyers, as everyone was astonished when the expert disclosed this during his evidence. The Claimant argued that the tactical decision to focus on design negligence rather than workmanship, whilst ultimately unsuccessful, was a legitimate forensic choice and did not take the conduct of the litigation outside the norm.
The Defendant’s position on ADR
The Defendant accepted the broad outline of the correspondence but submitted that the full chronology had to be considered. It emphasised that workmanship issues had been raised as the cause of the damage for four years before proceedings were issued, and that the Claimant had never substantively engaged with those allegations. The Defendant had provided detailed calculations when requested, had engaged fully in the pre-action protocol process, and had made Calderbank offers and Part 36 offers in the run-up to trial. It submitted that it was not refusing to engage in ADR but was reasonably requiring some understanding of the Claimant’s expert evidence before committing to a mediation process. It noted that the Claimant had refused to provide its expert report even on a without prejudice basis, and that the Claimant’s own stance immediately before trial, asserting that its Part 36 offer “was not made for negotiation purposes” and that it had “a strong case”, demonstrated that mediation would not have had realistic prospects of success. The Defendant also pointed to the Claimant’s imposition of onerous conditions on any mediation, including that the Defendant would have no say in the identity of the mediator appointed, and argued that the Claimant’s refusal to engage with workmanship allegations throughout the pre-action period made meaningful mediation impossible without expert evidence being available.
The Defendant’s position on the expert’s late change of evidence
The Defendant submitted that the mass concrete taper issue had limited materiality. The Particulars of Claim did not mention a mass concrete taper and did not assert that the failure to specify one was a negligent defect in the design. It was never part of the Claimant’s case that a mass concrete taper was required. The issue was only first mentioned in the experts’ joint statement dated 15 December 2023, and the detail of the Defendant expert’s evidence on this aspect came in his report served on 26 January 2024, just over one week before trial. By this time, the majority of costs were already incurred. The Defendant’s expert had explained that a further check was required after consideration of some of the points raised by the Claimant’s expert, and the court accepted that explanation. The additional calculations did not cause the Claimant to abandon its case and did not result in additional costs being incurred. The Defendant also submitted that it was wrong to assert that the expert simply changed his evidence on the number of dowels engaged by the design when the court accepted his explanation that a further check was required.
The Defendant’s position on indemnity costs
The Defendant asserted that the conduct of the Claimant and its legal team in relation to the instruction, oversight, and management of the Claimant’s expert was sufficiently outside the norm to justify an order for costs on the indemnity basis for the expert phase. The Defendant criticised the fact that the Claimant’s expert did not directly answer the question of whether the Defendant’s design was one that a reasonable body of engineers could have produced. Proceedings were issued, the experts’ joint statement produced, and expert reports exchanged without that question being answered. The Defendant asserted that the Claimant did not properly interrogate the application of the Bolam test, the Defendant’s causation arguments, the significance of the date by which the damage had become manifest, nor provide any evidence about what the correct design would be if the Defendant’s design was negligent. The Defendant also criticised the Claimant’s expert’s decision to use FE analysis to assess the Defendant’s design, his use of an out-of-date edition of a technical publication without disclosing that fact, his changes of position without explanation, and his decision to rerun the FE analysis over the weekend before trial without informing anyone. All of these factors, the Defendant submitted, showed the inadequacy of the Claimant’s expert’s compliance with CPR 35 and his expert duty, and justified a costs sanction.
The Court’s Decision
Costs to follow the event
Her Honour Judge Kelly ordered that the Claimant pay the Defendant’s costs, to be the subject of detailed assessment if not agreed. The judge accepted that the Defendant had declined multiple mediation proposals but held that this could not be assessed in isolation. The full chronology had to be considered, including the Claimant’s failure to engage with workmanship allegations raised in 2019, the 19-month delay in responding to the Defendant’s calculations, and the refusal to provide expert evidence even on a without prejudice basis.
Applying the Halsey factors, the judge found that it was not unreasonable for the Defendant to have refused mediation before having some understanding of the Claimant’s expert evidence. The Defendant had raised workmanship issues in response to the letter of claim, and the Claimant had asked for calculations to justify the Defendant’s design but did not deal with the alleged workmanship issues. The Defendant’s calculations were provided, but the Claimant then did not respond for 19 months. When the Claimant wrote again, it stated it had expert support for its case but once more did not engage with the workmanship issues. The Defendant asked for a copy of the expert report on a without prejudice basis and again raised the lack of response to the issues about workmanship and causation. The Claimant did not provide the expert report and did not engage with workmanship issues in any meaningful way.
The judge accepted that the Defendant did not agree to the continued suggestions of mediation without having some understanding of the expert evidence, but held that this could not be described as unreasonable. Other forms of ADR were proposed by the Defendant throughout, and offers were being made. The nature of the dispute would not prevent a successful mediation, but having actively engaged, provided calculations and justification as to why the Defendant asserted it was not negligent, it was not unreasonable to require a meaningful response to the points made before mediation. Mediation may have cost up to £50,000, which was not an insignificant sum, especially when the Claimant was not providing information which was reasonably requested.
Once the expert evidence was available, the Claimant’s offer to consider mediation was only weeks before the start of the trial and was offered only on potentially disadvantageous terms to the Defendant. The judge held that failure to agree to earlier mediation, nor to the last suggestion of mediation on the terms demanded, could not reasonably be held against the Defendant. The Defendant’s reasoned rejection of one form of ADR, namely mediation, was not unreasonable. The legal issues were clear and largely agreed between the parties. The case would always depend upon the court’s assessment of the expert evidence. The Claimant’s refusal to disclose its expert evidence (even on a without prejudice basis) and its apparent failure to instruct its expert to consider all of the workmanship issues raised by the Defence would inevitably have had a significant impact on the likely success of any mediation.
Even had mediation taken place, the judge did not accept that it would have had reasonable prospects of success. The Claimant had not engaged with the Defendant’s allegations of poor workmanship nor provided its expert evidence. The Defendant’s reasonable wish to understand the case it was meeting was not just going to disappear. Offers were being made both ways in the run up to trial, but the parties remained a vast distance apart.
The expert’s late change of evidence
The judge did not accept the Claimant’s assertions that a “late change” of evidence by the Defendant’s expert supported a decision that no order as to costs was the appropriate costs order. The judge found that the Defendant’s expert was in error in asserting that a mass concrete taper was part of the Defendant’s design. However, as the need for a mass concrete taper was never part of the Claimant’s case that the Defendant’s design was negligent, this did not have a material bearing on the outcome of the litigation. The Claimant’s expert did not assert that a mass concrete taper was needed to make the design work. The first mention of the need for a mass concrete taper was about two months before trial when the experts produced their joint statement. The need for a mass concrete taper was only if adequate compaction could not be achieved under the relevant joint. The detail of the Defendant’s expert opinion on the need for a mass concrete taper came in his report served about one month before trial.
In both the joint statement and the report, the Defendant’s expert made it clear that he knew that the mass concrete taper was shown on the design drawing for a different joint. However, he was of the opinion that the Claimant’s workmen should have inferred that a mass concrete taper was also required under the relevant joint, even though it was not shown on the design drawings, because of the compaction issue. The Claimant’s expert opined that the necessary compaction could be achieved and that was the finding the judge made. The Defendant’s expert also produced some additional calculations shortly before trial. However, as was stated in the judgment, that was done to enable him to consider the evidence of the Claimant’s expert and the criticisms of the design and the conclusions drawn from them. The judge held this was classically an example of the sort of final “sense check testing” the court would expect from an expert, particularly when the expert evidence has been finalised very late in the day before trial. The judge accepted the Defendant’s submission that this was “simply part of the usual cut and thrust of a professional negligence trial”. In those circumstances, it was difficult to see how any additional costs were caused by the late calculations in any event.
Indemnity costs refused
The Defendant’s application for indemnity costs in respect of the expert phase was refused. The judge reminded herself that the question was whether there was something in the conduct of the action or the circumstances of the case which took the case out of the norm in a way which justified an order for indemnity costs. The judge was just persuaded that the answer to that question was no, and costs should be assessed on the standard basis throughout.
The judge had made findings in the substantive judgment that the Claimant’s expert did not properly understand his duties to the court pursuant to CPR 35, that he did not appear to have considered adequately the applicable legal test, and he did not deal with the workmanship issues raised by the Defendant adequately. He used an outdated edition of a technical publication to justify some conclusions without providing any reference to the updated edition. He carried out additional tests and reran the FE analysis immediately before trial without telling anybody he had done this nor providing anyone with the results. The Claimant lost the case because the judge had no confidence in its expert.
The judge agreed with the Defendant’s submission that this was not simply a case of the court preferring one expert’s evidence over another. The reality was that the criticism of this expert went beyond that. However, the judge accepted that the Claimant’s solicitors had put the correct test in the expert’s instructions, and the expert had set out the correct test in his written report and answered questions in a way which would indicate that he was considering the correct test when giving his opinion. When cross-examined, it became apparent that he was not correctly applying the test and had not given consideration to various matters to which the judge found he should have given consideration. The judge accepted that a claimant is responsible for their expert for the purposes of costs. However, she did not accept that there was sufficient material before trial in the expert’s reports to indicate to the Claimant’s legal team that their expert was going to give evidence in the way that he did. Further questions could perhaps have been asked of the expert during the proceedings. That may have been an error or a tactical decision. However, the judge did not accept that the asserted failure to spot the various problems with their expert’s evidence was sufficient to pass the high hurdle before indemnity costs are justified.
The Claimant made various tactical decisions in how to pursue its case against the Defendant for negligent design. Some tactical decisions would always be needed when a company associated with the Claimant has carried out the construction work for the design and that work is criticised by the Defendant as being the cause of the damage. With hindsight, it may have been better expressly to instruct the Claimant’s expert to deal with the various workmanship defects asserted by the Defendant. However, as the Claimant took the view that it only needed to prove that the defective design was “a” cause of the damage, it did not need to deal with all of those workmanship issues. The tactic was unsuccessful, but the judge accepted that deciding on the tactic did not take the Claimant’s lawyers’ conduct “out of the norm”.
It may have been that the Claimant’s legal team restricted its frame of reference in respect of the expert evidence required because of the analysis undertaken by John Frith. However, the tactic of concentrating primarily on identifying a negligent design and then establishing the negligent design was a cause of the damage, whilst unsuccessful, could not be said to take the conduct of the case so far out of the norm. The further criticisms of the Claimant’s lawyers, such as refusing to answer Part 18 further information questions, the judge would not find to justify indemnity costs. If the Defendant felt that the refusal to answer the questions was unjustified, it could have made an appropriate application.
The Claimant’s counsel asked for clemency for the Claimant’s expert as his reputation had been tarnished by the judgment, and he would have to live with the consequences of that. The judge did not accept that clemency should form any part of the court’s consideration. The question was whether there was something in the conduct of the action or the circumstances of the case which took the case out of the norm in a way which justified an order for indemnity costs.
The judge did not accept that the combination of the Claimant’s tactics and the Claimant’s expert approaching the case in a more technical rather than practical manner, then effectively going off on a frolic of his own immediately before trial and not giving the evidence expected during his oral evidence, created circumstances to justify an order for indemnity costs. It was of relevance that the expert evidence timetable was “concertina-ed” into a short time frame before trial. The joint expert report became available about three months before trial and the individual expert reports then followed. Supplementary expert reports were filed because of additional factors raised in the various reports which required a reply. The judge did not find in the circumstances of this case that the conduct of the Claimant’s lawyers was such that the action was conducted, or the circumstances were such, that it was out of the norm in a way which justified an order for indemnity costs.
Payment on account
The parties were agreed that a payment on account of costs should be made. Applying the principles in MacInnes v Gross [2017] 4 WLR 49, the Defendant sought £312,700.75, being the approved budget in the sum of £344,082, less 10% bringing that sum down to £309,673.80 and then adding interest at 4% of £12,386.96, payable within 21 days. The Claimant sought a reduction of 20% to take into account the fact that there was not a mediation which had been part of the budgeted costs. The Defendant objected to further reduction as the budgeted figure was for all forms of ADR. There was no justification to consider individual phases to reduce further. Any adjustment could be dealt with at detailed assessment.
The judge held that the starting point for assessment of a reasonable sum was a 10% reduction. She did not accept that it was reasonable or proportionate to increase the percentage reduction further in this case. Mediation did not take place, but other forms of ADR did. Interest would run on the costs payable. The judge accepted that 4% interest on pre-judgment costs was a reasonable percentage. She awarded interim costs in the sum of £309,673.80 plus interest at 4%.
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Failure To Engage In ADR And Indemnity Costs, Again
Part 36 Validity, Protocol Breaches And Mediation Timing In Probate Disputes
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CPR 44.2 And The Courts’ Discretion As To Costs
