Whether you basked or battled your way through the blazing summer, subsidence was probably not at the forefront of your thoughts. But the press has already reported drought damage caused to roads this summer, and subsidence damage to buildings is bound to follow. Statistics show that hot summers are followed by spates of subsidence claims, moisture extraction by thirsty trees often being identified as the mechanism that links the two.
Tree root subsidence was the hot topic in these chambers this summer, with both parties in the case of Loftus-Brigham v Ealing being represented by members of chambers. This end of the corridor acting for the defendant local authority won at trial, while the other end of the corridor acting for the claimant householder prevailed in the Court of Appeal (Judgment 28.10.03). The Court of Appeal clarified the test to be applied when there are two competing causes of tree root subsidence damage. The new test is bad news for treeowning neighbours.
The claimant's house in leafy Ealing had several large plane and lime trees, owned by the defendant local authority, growing in the street nearby.The claimant's house, which was in the Gothic style, had been turned into a Hammer House of Horror backdrop by a variety of climbing plants and creepers that virtually engulfed it, covering the roof and even the windows. The house sustained considerable movement, the mechanism of which, the expert engineers agreed, was probably caused by vegetation. Loftus-Brigham claimed that the local authority trees were at fault. The local authority blamed the creepers.
Investigations found roots of both trees and creepers beneath the house.
The judge at trial had to decide between these two possible causes of subsidence and found ultimately that the claimants could not show that Ealing's trees were the 'dominant' cause of the damage, and that therefore the claim failed. The Court of Appeal held that the judge had applied the wrong test. In line with other claims in tort, the claimant only had to show that the event complained of was 'an effective cause'.The right test was whether the desiccation caused by Ealing's tree roots 'materially contributed' to the damage.The 'material contribution' test was taken from the law of occupational diseases.
In Bonnington Castings v Wardlaw (1956), for example, the claimant was injured by dust arising from two different aspects of his employment - a pneumatic hammer and swing grinders. The defendant employer was in breach of regulations relating to the grinders, but not the hammer.Happily for the claimant he only had to show that the dust from the grinders, for which the employer was liable, had made a material contribution to his injury in order to recover for all his loss.He only had to show that the proportion of the dust from the grinders was not negligible.
As a result of the decision in the Loftus-Brigham case, the material contribution test, when applied to tree root cases, may mean that a claimant has only to show that their neighbour's tree had some adverse effect on their property that was more than negligible. If that is so, a claimant will be able to claim for all the damage, regardless of other effects such as the claimant's own vegetation.
About 50 years ago, John Summerson observed that the fragility of London's Georgian houses was being exposed by the stresses of time, traffic and bombs. Today, we might add the changing weather pattern to his list. When the effects of increasingly extreme weather are combined with the potential liability of tree owners for all the damage caused to neighbouring properties, the result may be that large numbers of mature and amenity-enhancing trees are, literally, for the chop.
But don't rush for the chainsaw just yet. This end of the corridor has recently petitioned the House of Lords for permission to appeal the new test and save the trees.
Both parties are waiting to see whether their Lordships consider the matter of sufficient public importance to warrant a full hearing. Meanwhile, at least there is something to talk about over the coffee machine (halfway down the corridor) as we watch the late autumn rain swell London's shrinkable clay.