Blindly following ‘normal practice’ without considering the risks involved is no defence against an accusation of professional negligence.

Perhaps surprisingly, the fact that other professionals with similar experience and resources may have followed the same course of action does not excuse a professional firm from liability.Duty of care owed by a professional practice was at the heart of a recent case, 199 Knightsbridge Development Ltd -v- WSP UK Ltd. It involved WSP, a firm of mechanical and electrical engineers, which installed a pressurised cold water system in a block of flats in Knightsbridge. The joints used in the system failed, leading to severe flooding.

WSP claimed that it was not responsible for the flooding. It said that at the time none of the leading building services practices in the UK had identified the problem with the water system. WSP argued that no reasonable engineer would have foreseen or guarded against the events that occurred.

A professional’s duty of care has been defined in a number of court cases. In Bolam -v- Friern Hospital Management Committee (1957) it was held that a professional person ‘is not guilty of negligence if he acted in accordance with a practice accepted as proper by a responsible body of medical men skilled in that particular art’. Another case, Nye Saunders -v- Alan E Bristow (1987) considered whether an architect’s duty of care had been discharged. It decided that the courts would assess whether there was evidence at the relevant time that a responsible body of architects would consider that the manner in which the defendant discharged his duty was appropriate.

In the WSP case the court drew a distinction between the existence of a ‘responsible body of professional opinion’ and ‘industry practice’ prevailing at the time. The judge, Mr Justice Edwards-Stuart decided that despite the absence of a responsible body of professional opinion, the prevailing industry practice could not excuse WSP of its professional duty of care. He decided that WSP was negligent as it should have foreseen the problem and designed a water system with surge arresters to avert the risk of flood.

In a final twist the claimant’s case was dismissed. Even though it had been able to show that WSP had fallen short in its duty of care, it was unable to prove that it would have installed surge arresters had WSP advised it to do so.

This case shows clearly that professionals have to exercise a high standard of care in their work,” said James Burgoyne, Director – Claims & Technical, Brunel Professional Risks. “The case drew a distinction between accepted opinion within an industry, and general but effectively unconsidered practice. Consequently, just following usual industry practice will not be a defence if it can be proved that the professional should have foreseen the problem. Whilst consistent with existing legal principles, the highlighted distinction may come as a surprise, and is not good news for professional liability. It remains to be seen how the implications will be developed in future cases.

Further information on the case is available from Hill Dickinson, Clarks Legal and the Designing Buildings Wiki.