Court pours cold water on engineer’s “reasonable body of opinion” arguments

Professionals relying on the Bolam defence will need to show that a reasonable body of opinion supporting their actions has a rational or logical basis.

199 Knightsbridge Development Ltd v WSP UK Ltd. [2014] EWHC 43 (TCC))

  • Submitted 16 April 2014
  • Applicable Law UK
  • Topic Insurance


In the decision of 199 Knightsbridge Development Ltd v WSP UK Ltd. [2014] EWHC 43 (TCC), Edwards Stuart J concluded that the defendant engineers, WSP, ought to have foreseen the problem in question, even though at the relevant time not one of the leading building services practices in the UK had identified it.  The Claimant failed to show, however, that the steps which WSP should have taken would have prevented the loss.

Edwards Stuart J examined the appropriate authorities on the standard expected of a professional person, and outlined the basic principles to be applied. In essence, a professional man can argue that he was not negligent if his advice/actions accorded with a responsible body of opinion held by practitioners in that discipline, as long as that opinion is capable of being logically supported (the Bolam defence). A widespread failure (without logical support) within a profession to identify or foresee a particular risk or sequence of events, however, does not fall within that category.


WSP UK Ltd (WSP) was the M&E engineer who designed the cold water system on the Claimant’s development. In September 2005 serious flooding occurred, which was attributed to failures of the cold water system and pipework; on an automatic restart of the water pumps the velocity of the water, and the lack of air in the system to act as a buffer, created such pressure in the pipes that it caused them to burst.

The central issue in the Claimant’s subsequent claim against WSP was whether or not WSP was negligent in having failed to foresee these problems. The Claimant asserted that everything which occurred could have been foreseen, and that if WSP had foreseen the risk of a potentially catastrophic failure of the sort which occurred, it would have installed anti-surge valves which would have prevented the flooding. WSP argued that, at that time, it was not industry practice to install such valves, or advise that they be installed, and that they therefore could not be negligent when compared to the industry standard.


Edwards Stuart J, giving judgment, acknowledged that although the problem was obvious with the benefit of hindsight, not one of the leading building services firms had identified it prior to 2005. He found, nonetheless, that WSP, and other engineers in WSP’s position, should have foreseen the issue and taken steps to prevent it.

Edwards Stuart J drew four principles from the relevant authorities:

  • A professional man does not warrant to his client that a course of action will be successful
  • If a professional man adopts or advises a course of action which turns out to be wrong, but it was in accordance with a responsible body of opinion held by practitioners in that discipline, he will not be negligent as long as that body of opinion is capable of being logically supported (Bolam v Friern Hospital Management Committee [1957] 1 WLR 582 and Nye Saunders v Alan E Bristow (1987) 30 7BLR 92)
  • If the exponents of the “responsible body of opinion” cannot show that the opinion has a logical or rational basis, the Bolam defence is unlikely to succeed (for example Bolitho v City & Hackney Health Authority [1998] AC 232)
  • If the reason why the impugned course of action or advice was wrong is that the professional man in question and others in his position has failed to identify or foresee a particular risk or sequence of events, there is probably no room for the Bolam test (for example, JD Williams v Michael Hyde [2001] PNLR 8)

In this case, Edwards Stuart J found that in failing to think through the implications of their design WSP fell below the standard required of reasonably competent engineers. WSP should have appreciated the risk of an abnormally high pressure surge on automatic restart of the pumps following an unplanned shutdown, and investigated that in more detail. Although WSP was not alone in having failed to appreciate the risks, they should have done so; there was no responsible body of opinion which provided any properly reasoned or logical basis for their failure to consider the issues. 

The Claimant’s case, however, failed on causation. Even if WSP had foreseen the risk, and advised that anti-surge devices should be installed, it was unlikely that these would have been fitted in time to prevent the incident in question. Further, the court was not satisfied that even if WSP had advised the Claimant to fit anti-surge devices, the Claimant would have done so, and there was no evidence that other procedures by which the surge, and subsequent flooding, might have been prevented (such as a slow refill after the restart of the pumps) would have been followed.


This decision provides a useful summary of the principles governing the standard of care which will be applied to a professional person who finds him or herself accused of negligence. The Bolam defence has limits, so that a professional cannot simply rely on the fact that no one else in the industry knew of the risks either. They will need to provide evidence that within the relevant industry there is a “responsible body”, whose opinion supports their actions and advice on a rational or logical basis.  A widespread failure within the relevant industry to recognise a particular risk, and/or foresee the consequences, will not suffice. Professionals still need to look closely and afresh at the potential risks of a piece of advice or action, and not rely solely on established industry practice.

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