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Flood damage: 199 Knightsbridge Development Ltd v WSP UK Ltd

High Court (TCC)

The defendant failed to appreciate that the water system they designed could create an excessive pressure surge which would rupture water pipes and lead to a major flood. Whilst the defendant had breached the duty they owed to the claimant, the claimant failed to adduce evidence to show that the breach of duty was causative of the claimant’s loss. Christopher Ryan and Rachel Coppenhall look at the evidential lessons to learn from the decision in 199 Knightsbridge Development Ltd v WSP UK Ltd (2014).


The claimant was the freehold owner of a prestigious apartment block known as “The Knightsbridge.” The defendant was the Mechanical and Electrical engineer tasked with designing the cold water system. With the advent of high rise buildings, it had become common practice to utilise pump systems rather than the traditional gravity fed systems.

A feature of the design at The Knightsbridge was the use of non-return valves to prevent air being introduced into the risers. On 15 September 2005 there was an unscheduled and unexpected shutdown of the water pumps and the system partially drained down. When the pumps were restarted water was forced back up the risers at high velocity. The absence of air to cushion the flow of the water created a significant surge pressure resulting in pipes on the 6th and 11th floors rupturing causing a major flood.

The contract required the defendant to “exercisea reasonable level of skill and care as (was to be) expected of a qualified Consultant in the same profession, experienced and competent in carrying out work of similar size, scope and complexity as the Project”

The claimant contended the above duty had been breached. Had the defendant thought through their design, they would have foreseen that failure could have occurred in these circumstances. The defendant argued that they were not negligent as not one of the leading building services practices in the UK had identified this problem prior to 2005. Edwards-Stuart J commented that “one of the striking features of this case is that, with the benefit of hindsight, the potential problem can be identified without any great difficulty”


Edwards-Stuart J dismissed the claimant’s claim:

Legal Principles

In considering the duty owed by the defendant, the starting point was the nature and extent of the contractual obligation. Bolam v Frien Hospital Management Hospital Management Committee (1957) holds that a professional person is not in breach if he has acted in accordance with a practice accepted as proper by a reasonable body of men skilled in that particular art.

  • Other relevant principles from the authorities were as follows:

    • A professional man does not warrant that a course of action that he takes or advises his client to follow will be successful.

    • If the course of action advised is unsuccessful or shown to be wrong, it will not be negligent provided that it was in accord with a reasonable body of opinion held by practitioners at that time, and, that body of opinion has a logical or rational basis. (Bolitho v City and Hackney Health Authority (1998))

    • If a logical or rational basis cannot be shown, the defence is likely to fail.

    • If the disputed course of action or advice is wrong because the professional did not foresee a particular risk or sequence of events, Edwards-Stuart J felt there was probably no room for the Bolam test. This was because typically the Bolam test is appropriate where the neglect is said to lie in a conscious choice of available courses made by a trained professional, and that it is not appropriate where it is an oversight that the breach is said to lie (Sedley LJ in JD William & Co Ltd v Michael Hyde Associates Ltd (2001))

Breach of Duty

  • The defendant faced difficulties as the documentary evidence of the design course taken was “somewhat sparse” as a result of losing much of the documentation in a fire in 2006.

  • The lead engineer was called by the defendant. His evidence was that the design of the system was the responsibility of the public health engineers. Those engineers were not called, despite having the closest involvement in the design of the system.

  • The defendant’s expert public health engineer was unable to provide a logical or reasoned basis for the approach adopted. Working through each of the steps of the mode of failure the defendant’s own expert agreed that they were all reasonably foreseeable by a competent mechanical services engineer.

  • When the defendant’s engineer commissioned the booster sets (mid 2004) they should have applied their mind to how the pumps would respond to certain situations, one being an unexpected shutdown. The defendant should have appreciated that restarting the pumps following a partial drain could result in abnormally high pressure surges when the pumps were restarted.

  • Had this been appreciated and had the manufacturers of the pumps been advised then a slow fill procedure could have been devised or a new valve (known as an anti-surge valve) introduced to prevent excessive pressure surges.

  • On the evidence, breach of duty was established by the claimant.


  • The claimant also faced evidential difficulties;

    • There was no evidence from the witnesses who took the decision to turn the pumps back on as to whether they would have followed a slow fill procedure.

    • No evidence was given by the claimant to show that had they received advice regarding the anti-surge valve, they would have followed that advice. In fact even after the flood the claimant chose not to have the anti-surge valves fitted.

    • In any event, even if the claimant did accept this advice, the valves (which were new to the market) were unlikely to have been evaluated and fitted in time to prevent the flood.

  • The case therefore failed as a result of being unable to show that the breach of duty was causative of the claimant’s loss.


Despite breach being established, the lack of evidence on causation was fatal to the claimant’s claim. It serves as a salutary reminder that it is for the claimant to prove their case as to duty, breach and causation.

As a defendant there are three useful ways to build a defence to a claim such as this. Firstly a defendant should look to limit the nature of their duty. Secondly, every effort should be made to ensure that the claim is one which falls within the realms of Bolam. If it does, appropriate evidence to demonstrate that the course of action has a logical or rational basis will be crucial, in particular where the case concerns industry practices. Thirdly, if liability may be established, obtain evidence which will demonstrate that the advice would not have been followed, or even if it was followed, it would have made no difference to the outcome.

Conversely, a claimant needs to be alive to the Bolam defence. They should look to exploit the Bolam exception described by Edwards-Stuart J and seek to show that despite a course of action being in line with a practice within an industry, there is no logical or rational basis for that course of action. Finally, as illustrated in this case, the claimant should ensure that they have considered causation and obtained suitably robust evidence on that aspect of the claim.


For further details, please contact Rachel Coppenhall, Solicitor, on 020 7645 9557 or Christopher Ryan, Partner, on 20 7645 9550.

This information is intended as a general discussion surrounding the topics covered and is for guidance purposes only. It does not constitute legal advice and should not be regarded as a substitute for taking legal advice. DWF is not responsible for any activity undertaken based on this information.