In mid January 1974 the Defendants were excavating their site enclosed within a cofferdam for 3 basement floors. They were in the course of erecting a 13 storey building. During this period, the owners of buildings in the neighbourhood complained that cracks had appeared in their buildings. Some of the cracks were quite severe. Among the neighbours were the Plaintiffs whose building suffered extensive cracks and who now claim damages for loss of support, nuisance as well as negligence against the Defendants.

Central to the causes of action is the Plaintiffs' allegation that by reason of the excavations, the bottom of the hole thereby formed heaved upwards and the ground upon the sides of the cofferdam moved downwards and laterally towards the excavation hole, having passed underneath the sheet piles surrounding the Defendants' land, with the consequence that the surface ground in the immediate vicinity subsided and the buildings standing on them therefore suffered cracks. In short, the Plaintiffs alleged that some sort of base heave had occurred at the excavation site which, if proved on a balance of probabilities, must mean that the Defendants were liable in law for