On 13 July 2012, the Court of Appeal found that neither Islington Council in London nor Family Mosaic Housing Group, which owned the property next to a home that had been damaged, could reasonably be expected to foresee that their trees might pose ‘a real risk’ of causing damage to the property until they had been notified that the property had suffered damage and reasonable evidence had been provided.
Until that point, both Family Mosaic and Islington had satisfied their duty to eliminate or minimise potential nuisance and could not be held liable for prior damage as they had acted reasonably, the court found.
Both the trial judge and the Court of Appeal found that there was no ‘real risk’ of reasonably foreseeable damage from the adjoining trees.
The trial judge, His Honour Judge Wilcox sitting at the Technology and Construction Court, dismissed the claim finding that prior to damage occurring to the claimant’s property, neither defendant could have appreciated that there was a ‘real risk’ that their trees would cause damage. The claimant’s interpretation of the test of ‘reasonable foreseeability’ in that where a building is within influencing distance of a tree there was a risk of damage, lead the trial judge to say that: "[Islington], mindful of its obligation under Town and Country Planning Acts and the preservation of such amenities as a treed environment, could not reasonably contemplate the desertification of such a neighbourhood by wholesale tree felling to avoid the risk of damage. Such an approach it seems commended by the claimant almost gives rise to strict liability"
London Tree Officers Association chair Jake Tibbetts said: "This is a very important and welcome decision regarding alleged subsidence claims involving trees. This case re-emphasises how the law should be applied, and sets a positive precedent for lower courts (who decide the majority of these claims). It also goes someway towards rebalancing the law’s view on trees and reasonableness between 'neighbours'. As the manager of Islington’s Tree Service, I thought it important to give my perspective on the outcome of this case.
"I believe that this case could result in reducing significantly the numbers of subsidence claims and the value of those claims against councils who manage trees in a reasonable manner. Tree owners can now argue that they are not liable for damage that has occurred prior to them being made aware that damage has occurred, solely on the basis of a potential risk. In this case, it was only when the potential risk became a real risk that the liability for damage passed to the tree owners.Kal Sandhu of commercial law firm Clyde & Co acted on behalf of Islington in both the trial and the appeal. He was instructed by Zurich Municipal, who supported Islington’s stance that the risk of damage was not reasonably foreseeable.
She said: "The Court of Appeal confirms that when assessing whether there is a ‘real risk’ of tree related subsidence damage, one must consider whether the relevant trees present a risk, the nature and extent of which imposed upon the owner a duty to take preventative or remedial action."
"The obstacles to the claimant succeeding on her appeal, required her to show either (i) that the trial judge was wrong to find that Islington had in place a prudent regime of pruning or (ii) that Islington should have had a cyclical pruning policy thereby showing an alternative to wholesale removal or the ‘desertification’ the trial judge referred to. Had she overcome those hurdles, she would still have needed to persuade the Court of Appeal that the judge’s findings on causation were incorrect.
"The claimant had pleaded that the defendants had failed to ‘pollard, crown or otherwise manage or control the growth’ of the implicated trees. However, the evidence of her arboricultural expert, Mr Kelly (the co-author of a paper entitled "Tree related subsidence: Pruning is not the Answer"), as found by Lord Justice Tomlimson, "did not support the Claimant’s pleaded case insofar as that alleged a failure properly to manage trees by pruning prior" [to the damage occurring]. The expert arboricultural evidence had not identified the implicated trees as posing a greater risk than others, or that they should have been subjected to a regime other than the one adopted, or indeed that pruning would have eliminated or minimised the risk in any event."