Avantage (Cheshire) Ltd v GB Building Solutions (in administration) [2023] EWHC 802 (TCC)

A recent interim application before the Technology and Construction Court (TCC) provides helpful guidance on when a party in Court proceedings can replace experts. 

In this case, the application was made by the Claimants to replace two experts in a case involving fire safety defects, at a stage close to commencement of the trial. Although the TCC permitted both replacement experts, the terms upon which permission was granted differed due to the distinct reasons given by the Claimants as to why new experts were necessary.


In 2019, a fire occurred at Beechmere retirement village in Crewe, destroying almost the entire property. The fire appeared to have started as a result of ‘hot works’ carried out by a roofing contractor, MAC (Roofing & Contracting) Limited. The Claimants sought damages of more than £40 million in respect of the alleged deficiencies in the design and construction of the property.

Proceedings were issued. The Court gave the Claimants permission to call multiple expert witnesses, including:

  1. Ms H, a forensic scientist, to give evidence in relation to the cause, origin and spread of the fire; and
  2. Mr W, a fire engineer, to give evidence as to the adequacy of the fire strategy, whether the design complied with Building Regulations at the time and whether the design should have included sprinklers.

Unfortunately, Ms H became seriously ill and the trial was adjourned as a result.

Subsequently, the Claimants issued an application seeking to replace both Ms H and Mr W, with each application made in very different circumstances:

  1. Ms H’s replacement was on the basis of her serious illness which requires treatment and prevented her from continuing to participate in the proceeding;
  2. Although the reasons for the Claimants application to replace Mr W were unclear initially, during the course of the application hearing, the Claimants counsel had been 'frank' with the Court that the Claimants were not happy with Mr W as an expert.


The Court has a general discretion to permit a party to change the identity of an expert having regard to all of the material circumstances of the case and in accordance with the Overriding Objective. The usual rule is that the Court should not refuse a party permission to rely on a new expert in substitution for an existing expert.

However, the Court has the power to impose conditions on permission to rely on a new expert by ordering the disclosure of documents including the original expert’s reports containing the substance of the expert’s opinion. This is to discourage ‘expert shopping’ on the basis that an expert’s adverse views may become public and to ensure that the expert’s contribution is available to both the Court and all parties.

Ms H

Unsurprisingly, the Court had no criticisms of the Claimant’s application to change experts due to Ms H’s ill health. The issues that Ms H were dealing with were critical in the case and although the Defendants did not object to the replacement they argued that the Court should grant permission subject to Ms H’s expert reports (including drafts), site inspection reports and notes of any interviews with witnesses being disclosed.

The Court considered that it would be unjust to impose this condition. The only order for disclosure was relating to notes taken by Ms H as part of site investigations that took place shortly after the fire on the basis that they were of evidential value.

Mr W

The replacement of Mr W was more complex. Initially, the Claimant’s arguments were that they were simply not happy with Mr W as an expert. The concerns raised by the Claimants later on in the hearing were around Mr W expressing views on matters that were more properly covered by the other experts, and not undertaking a careful and detailed review of documents.

The Defendants opposed the application on the basis that this was ‘expert shopping’. Alternatively, the Defendants argued if permission were granted, it should be on the condition that disclosure obligations were imposed.

The Court held that it was in the interests of justice that the Claimants should have permission to rely on an expert in whom they have confidence, which meant substituting Mr W. However, on account of Mr W being both available and qualified to give evidence, the Court imposed a condition that his reports (including drafts) must be disclosed, along with any further documents detailing his opinion within the scope of his original permission order by the Court. The Court found no indication of culpable behaviour or ‘expert shopping’ on the part of the Claimants or their experts, so disclosure of attendance notes was not ordered.


This case demonstrates that the Court is mindful of parties seeking to abuse the expert process in terms of expert evidence.

If a party is looking to apply for replacement experts, they should be cautious of ‘expert shopping’ and be aware that the Court has the power to attach disclosure obligations to any permission granted, which may lead to more severe consequences by undermining both their case and credibility.

Where an application for substitution must be made, this case has shown it is best to be completely transparent to the Court about the reasons why as early as possible.


This article was co-written by Natalie Cernuschi, Trainee Solicitor.

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