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Required or Desired?

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By Mark Roach & Morgan Raines


Published 29 June 2023


A review of (1) Avantage (Cheshire) Ltd (2) Cheshire East Borough Council (3) Your Housing Ltd v (1) GB Building Solutions Ltd (in administration) (2) PRP Architects Holdings Ltd (4) Prestoplan Ltd (5) WSP UK Ltd (6) Mascot Management Ltd [2023] EWHC 802 (TCC)

This TCC case provides guidance on what the disclosure requirements would be if a party were granted leave to replace Part 35 named and appointed experts. 


This case relates to a fire that took place at a care home in 2019, which destroyed almost the entire village.  The Claimants sought damages in respect of deficiencies in design and construction including the lack of compartmentation, cavity barriers and sprinklers to the tune of circa £40 million.

The Application

The Claimants applied to replace two of their experts – Ms Hooten (forensic expert) and Mr Wise (fire engineer) with one expert, Mr Ketchell.

The Defendants did not oppose the application for replacement of Ms Hooten because she could not continue with the case, due to medical reasons.  However, the Defendants did argue that Ms Hooten's reports, opinions and investigation notes should be disclosed.

The Defendants opposed the application relating to Mr Wise noting that the Claimants wanted to replace him and there was no proper explanation for the proposed substitution.  If the court allowed the substitution, it should be subject to the court ordering disclosure of Mr Wise's reports, opinions and notes.

Expert Substitution – The Facts and Principles

Following the CMC, the court granted permission for specific Part 35 experts to be used.  Therefore the court's permission was required for any replacement.

An applicant must show "good reason for the substitution."  However, the court has power to allow a substitution and the basis on which the court should exercise that power was discussed in The University of Manchester v John McAslan [2022] EWHC 2750 (TCC).

The relevant principles are:

  • The court's discretion should be exercised having regard to all material circumstances and in accordance with the overriding objective;
  • The usual rule is that the court should not refuse the requesting party;
  • The court has the power to permit the substitution on the condition that the original expert's reports, notes, etc are disclosed (and this is usually imposed). It can extend to other documents, but there must be a strong case in order to justify disclosure of solicitor's attendance notes; and
  • Justification for this is to prevent expert shopping and ensure the expert's information is available to the court and other parties.


Ms Hooten

Noting that the Claimants were "forced" to replace Ms Hooten, the Court decided that her expert reports, draft reports or other documents setting out her opinion were not disclosable.  However, the Court ordered that her notes and documents produced during her early stage inspection of the property and interview notes with a residents should be disclosed since they contained relevant primary evidence on the basis that:

  • the remnants of the care home had since been demolished;
  • the interviewed residents were unable to recall their conversations; and
  • the new expert would have access to these notes.

The Court noted that "In those circumstances, fairness and transparency, require that this material should be made available…".

Mr Wise

The Court noted that the reason for substitution of Mr Wise was not made very clear in written submissions.  However, during trial, Counsel for the Claimants confirmed that they were not happy with him for a number of reasons. 

Understandably, the Defendants were concerned about expert shopping. However, the Court disagreed that it was expert shopping confirming that, "It is in the interest of justice that the claimants should have permission to rely on an expert in whom they have confidence."

Substitution was granted subject to disclosure of reports (and draft reports) and any other documents where Mr Wise expressed an opinion.  Solicitors' attendance notes were not required to be disclosed due to the practical difficulties in producing redacted versions and it would be an "unnecessary invasion of the claimants' privilege in circumstances where there is no suggestion of any culpable behaviour on the part of the claimants or the experts."


On an academic level, this case sees the Court's justification for and powers to prevent expert shopping pitted against litigation privilege.  In the wake of this decision, there may well be some further debate on privilege vs the Court's powers to call for disclosure. 

That said, whether replacement is required or desired, the main practical takeaway is that disclosure obligations are more burdensome where a party wishes to replace an expert, but less burdensome where a party is forced to do so.