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Court denies party leave to adduce expert evidence

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Authored by: KK Cheung

The court recently dismissed an application by the Plaintiff in Kader Industrial Company Ltd v Hop Shing Engineering & Construction Co Ltd, [2021] HKCFI 3606, for leave to adduce expert evidence on issues of liability and quantum in a dispute concerning a Guarantee provided by the Defendant to the Plaintiff in respect of waterproofing works. The court dismissed the application, as it was not satisfied that the expert evidence proposed to be adduced would be of any assistance to the court for the determination of the issues in dispute.  


Plaintiff’s Claim

The Defendant carried out waterproofing works at the Plaintiff’s premises (Building). The Plaintiff claimed that upon completion of the works on 1 November 2013, defects were found in the works, namely water leakage and water stains on the ceiling of the 12th floor of the Building, which caused plaster to fall off from the ceiling and rust and deformation of the underlying rebar, which became exposed (Defects). The Plaintiff claimed that the Defects were caused by the defective roof waterproofing system installed by the Defendant on the roof level/13th floor of the Building and claimed under a Guarantee said to have been provided by the Defendant to the Plaintiff in respect of the quality of the works and waterproofing materials used.

Defendant’s Defence

The Defendant denied that the Guarantee was valid. In any event, the Defendant claimed that under the Guarantee, the works of the Defendant said to be subject to the Guarantee (roof waterproofing works and lapping to the existing waterproofing membrane) were to be carried out in conjunction with the Defendant’s installation of a green roof system, which was carried out by a third party, Everplant Technology Ltd (ET). The Defendant denied the Defects complained of and that they were caused by any defect in the roof waterproofing system provided by the Defendant on the roof level/13th floor of the Building. It claimed that such was caused by the destructive manner in which ET had removed and reinstalled the green roof system, which had caused damage to the 13th floor of the Building and/or damaged the Defendant’s works, causing the alleged Defects. In particular, the Defendant claimed that after its works had been completed on 1 November 2013, the entire green roof system of the Building had been removed in September 2019 and the remainder of the roof demolished in August 2020, when a third party contractor was engaged by the Plaintiff to carry out works, allegedly to prevent water leakage at the premises affected.

Application for leave to adduce expert evidence

The Plaintiff sought to adduce expert evidence by a Mr Boris Yeung (BY) on whether the waterproofing system installed by the Defendant was defective, the cause and extent of the Defects, and the reasonable cost of necessary repairs to rectify them. The Defendant opposed the application on the basis that the proposed expert evidence would not be cogent, reasoned or relevant to the pleaded issues, to be of assistance to the court at trial. The Defendant also asserted that BY was not qualified to give the expert evidence required.

BY inspected the 13th floor of the Building. The Defendant objected on the basis that the Defendant had not been given the opportunity to inspect the alleged Defects complained of and that BY’s own inspection was conducted after the green roof system had been removed and the entire roof had been demolished. BY’s inspection could not therefore have been of the Defendant’s waterproofing works, and as such, BY could not express any independent expert opinion on whether the works carried out by the Defendant were defective, nor as to the cause of the water leakage.

In the course of the hearing, the court asked the Plaintiff’s counsel to identify the factual evidence on the state or condition of the Defendant’s works prior to removal of the green roof in September 2019 and demolition of the remainder of the roof after August 2020. The Plaintiff’s counsel referred to an inspection report dated 24 April 2020 prepared by Hong Kong Survey Limited (HKSL Report), on water seepage tests conducted in March and April 2020 and pointed out that the HKSL Report had been disclosed in the course of discovery. The Plaintiff’s counsel also referred to photographs taken of the ceiling on the 12th floor of the Building, in April and June 2018, and on a CCTV Survey Report of a survey carried out on 29 August 2018, when a CCTV camera was lowered and moved along the drainage pipe serving the relevant parts of the Building. The Plaintiff’s counsel explained that this was the evidence to be relied upon by the expert to be appointed, for the expert’s opinion on the existence and cause of the Defects.

Court’s Decision

The court held that the HKSL Report was inadmissible evidence, on which the proposed expert could not rely. It said that evidence includes not only evidence of opinion, but also factual evidence which goes to an expert issue. Where an expert is drawing an inference from facts, on the basis of his expertise, experience and specialist knowledge, that is part of his expert evidence.

The court said that conduct of hammer tapping and infrared tests require experience and the employment of skills and specialist knowledge. The conclusion made, that damage exists or has been noted from the tonal or other relevant changes detected in the course of tapping tests, is a process of inference made by the operator or examiner, drawn from and dependent on the skill and experience of the operator. The reliability of infrared thermography tests likewise depends on the interpretation of thermal images, and whether the measurement devices were correctly applied with the relevant expertise. On such analysis, the HKSL Report, made on the basis of inspections and tests carried out in March and April 2020, including infrared scans and electrical conductivity sensing, clearly constituted expert evidence for which leave of the court was required. No leave had ever been sought or granted for the HKSL Report to be adduced, for BY to rely upon. The photographs relied upon by the Plaintiff only showed to a layman, the court said, that there were water stain marks or signs of spalling on the ceiling of the 12th Floor in April and/or June 2018. They could not show the cause of the water seepage, or the alleged Defects.

As such, the court said that without having inspected the condition of the roof and state of the Defendant’s works prior to the removal and demolishing of the green roof system and roof before September 2019, it was dubious whether BY could form any reliable opinion on the quality of the Defendant’s works and materials used, whether the Defects existed, the cause of the Defects, and the rectification works required. The court was not satisfied that the expert evidence proposed to be adduced by the Plaintiff would be of any assistance to the court for the determination of the issues in dispute. The court added that time and costs would be wasted if leave was granted for BY to adduce expert evidence, when there was a clear lack of the necessary factual evidence to form the basis of and to support his opinion. Further, the court was not persuaded that, as an architect, BY had the necessary expertise to give the expert opinion on the cause of the water seepage and leakage complained of, nor on the costs of the necessary rectification works.

Accordingly, the application for leave to adduce expert evidence, as framed, was dismissed.


Although it is common to adduce expert evidence in construction disputes, the court may not grant leave for the parties to do so as a matter of course. This judgment is also a good reminder to the parties that they should consider whether expert evidence is needed for their case as early as possible. Inspection of defects is usually necessary before the expert is able to form any opinion on them. The expert merely looking at record photos or reports done by others may not be acceptable to the court. In this regard, preservation of evidence is therefore important.

An architect or building surveyor is often appointed as expert on the issue of water seepage and leakage cases. It is not clear why the court was not persuaded that the architect in the above case had the necessary expertise to give an expert opinion. In rejecting the candidate, although not reported in the judgment, the court may have considered his experience in dealing with similar issues and his qualifications.

Key Contacts

Kwok Kit (KK) Cheung

Partner | Litigation and Dispute Resolution

Email or call +852 2825 9427

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