199 Knightsbridge Development Ltd v WSP UK Ltd

A professional designer may be negligent despite conformity with prevailing industry practice where the practice was adopted without identifying and logically assessing the relevant risk. The Bolam test remains applicable where a responsible body of professional opinion has a logical or rational basis, but there may be little scope for it where the alleged negligence consists of failing to foresee a sequence of events. In designing a boosted cold-water system, reasonably competent engineers should have considered partial drain-down, the resulting partial vacuum, rapid refilling and the risk of catastrophic pressure surges. The claimant must nevertheless prove that the breach caused the loss. A breach of duty does not establish causation where the proposed precautions would probably not have been implemented or would not have prevented the failures.

The claimant owned a high-rise apartment building whose cold-water system had been designed by the defendant M&E engineers. After an unexpected shutdown of the booster pumps, occupants continued to draw water, causing partial drain-down of the risers. When the pumps were briefly operated and later restarted, two pipe failures caused extensive flooding.

The claimant alleged negligent design and failure to warn, including failure to address pressure surges, specify suitable controls or procedures, and recommend anti-surge valves. The defendant contended that the relevant events were not reasonably foreseeable and that the accepted industry design practice provided a defence. The central issues were breach of duty, the scope of the duty, the alleged trigger events, and causation.

1. Duty and standard. The contractual obligation required the defendant to exercise the reasonable care and skill expected of a qualified consultant experienced in work of similar size, scope and complexity. The applicable professional standard was informed by Bolam v Friern Hospital Management Committee [1957] 1 WLR 582, subject to the logical-basis requirement in Bolitho v City & Hackney Health Authority [1998] AC 232.
2. Conformity with general industry practice was not decisive. The defendant had not shown a responsible body of opinion that had identified and considered the relevant risks and adopted a logically or rationally based response. Where the alleged failure consists of overlooking or failing to foresee a risk sequence, there is probably little scope for the ordinary Bolam defence.
3. By mid-2004, a competent engineer should have appreciated that an interruption in supply could cause partial drain-down and a partial vacuum, and that water could then travel through the risers at velocities capable of producing damaging pressure surges on refilling. The risk was within the scope of the defendant’s duty.
4. The defendant should have raised the issue with the pump manufacturer by the commissioning stage, considered manual restart and controlled refill arrangements, and later recommended anti-surge valves when their availability and suitability became known. However, manual restart would not have prevented the brief manual operation of the pumps, and the claimant failed to prove that a slow-fill procedure would have been followed.
5. The sixth-floor joint probably failed when two pumps were briefly operated. The eleventh-floor pipe probably failed when the pumps were subsequently restarted in automatic mode. Anti-surge valves would have prevented the failures, but the claimant failed to prove that they would have been installed in time, or that the claimant would have accepted the recommendation.
6. The claim was dismissed. The pleaded and evidential case did not permit reliance on a proposed failure to recommend potentiometers, and that alternative case would in any event have failed for want of proof.

First-instance decision in the High Court (Technology and Construction Court). The judgment records no appeal or earlier decision in the same litigation.