Tree root subsidence: Spotlight on recent case law

Robbins v Bexley London Borough Council (2012) is the latest case on the issue of local authority liability for tree root damage to come before the courts. Having reserved judgment to consider Berent, the High Court held that even though the local authority had not been notified of any damage to the property, the damage was still reasonably foreseeable as the trees had caused damage to other local properties and, once that was known, remedial action should have been taken. John Morrell examines why the Defendant was found liable.


In the recent Berent decision, the Court of Appeal stressed the requirement that a claimant establish foreseeability on the part of the defendant in a claim for tree root subsidence damage. An illustration of the court's approach to foreseeability in practice is now to be found in this High Court case.


The Claimant's property was one of a row of semi-detached houses backing onto a line of mature poplar trees growing in a Local Authority park. There were, or had been, other trees nearby, particularly a magnolia tree in the Claimant's garden, and an oak tree in a neighbouring garden. Damage to the Claimant's property was first noticed in 2003. More serious damage then occurred in the summer of 2006 with more minor damage occurring again in the summer of 2007. The experts agreed that damage had been caused by the abstraction of moisture by tree roots. The question was identifying the tree or trees which were responsible. The Claimant's case was that damage had been caused by one of the Council's poplar trees and that the Council had not done enough to restrict the size of the poplar tree and its consequent uptake of water.

Causation – which tree?

The Claimant's argument was based on the proximity of the Council's poplar tree and that after the tree had been pruned in September 2006 damage to the property was much reduced.

The Council argued that its poplar tree could not have been responsible because:

i) only one poplar root was found in boreholes (in fact, there was very little evidence of the existence of tree roots);

ii) the sub-soil had already been desiccated in the winter of 2005/2006, there was an early spring drought in 2006 which meant that the sub-soil conditions were already close to causing damage and that very little further had been required during the summer of 2006 to "tip the balance";

iii) the distance of the poplar tree from the property exceeded the maximum distance found in research by Cutler & Richardson on damage caused to properties by poplar trees;

iv) research published in 2004 by "Hortlink" showed that crown reduction of a tree by at least 70% was required to reduce the water uptake by that tree.

Judge's decision on causation

The judge took the view that the real question was why the settlement of the Claimant's property had been substantial during the summer of 2006 and much reduced during the summer of 2007. He held that the pruning of the Council's poplar tree, which had taken place in September 2006, had been "very severe indeed", thus reducing the water uptake by the tree, and he noted that there had been severe rainfall in 2007. Although the judge noted the distance of the poplar tree from the Claimant's property, he also observed that the row of poplars had previously been found responsible for damage to neighbouring properties. The judge therefore accepted the Claimant's case on causation and held that damage had been caused by the Council's poplar tree.


The judge noted that the research by Cutler & Richardson was widely regarded as authoritative in terms of the distance at which particular species of trees can cause damage. Thus, if a tree is further away from a damaged property than the maximum tree-to-damage distance recorded for that type of tree, then it is usually assumed that damage at that distance was not reasonably foreseeable. This is an important general point. Here, the tree to damage distance was greater than the maximum found in the research, which pointed against reasonable foreseeability. However, the judge noted, as above, that the row of poplar trees had previously caused damage to neighbouring properties and he took this to be "the clearest possible evidence" that the roots could extend further and that it suggested that roots from the Council's poplar tree, even taking into account the distance of the tree from the Claimant's property, could cause damage.

What should the Council have done?

The judge noted the following chronology:

1998 It was likely that the tree had been crown reduced.
2004 An order was issued for crown reduction of a number of the poplar trees, but this work was not carried out.
2005 A further works order was issued, but this work was not carried out until September 2006.
2005 (Dec) The Claimant's arboricultural experts requested removal of the Council's poplar tree. The Council's insurers then wrote to say that there would be 20-30% crown reduction, but no work was done until September 2006.
2006 (Sept) There was "very severe pruning" of the Council's tree.

The judge held that the work scheduled for 2004/2005 should have been carried out and that it was likely that it would have comprised the "very severe pruning" which was later carried out in September 2006. Had this work been carried out, the judge held that the damage suffered in the summer of 2006 would not have occurred.

The judge went further and held that because damage had been reasonably foreseeable in 1998 a decision to carry out work to the tree should have been taken at that stage. Documentary evidence showed that in 2006 the Council's prevailing practice was to carry out cyclical pruning every four years. This is what the Council should have done since 1998. Finally, the judge held that it was not until publication of the "Hortlink" study in mid-2004 that the Council could have appreciated that only very severe crown reduction or indeed felling of the tree was effective to reduce water uptake. The Council could not be criticised for rejecting any suggestion that the tree be felled as opposed to pruned at regular interviews. The Council could not have been criticised if it had carried out crown reduction work to its poplar trees every three or four years from early 1998 onwards.

Berent v Family Mosaic Housing (2012) CA

The judge's attention was drawn to the Court of Appeal's decision on foreseeability in Berent. In that case it will be recalled that the Court of Appeal did not interfere with the judge's finding that it had not been foreseeable to the Council that roots from its tree were causing damage to the Claimant's property until this was drawn to their attention. The judge considered that Berent did no more than set out well-settled principles relating to foreseeability and causation. Here, the risk of damage to the Claimant's property by the Council's poplar tree was "clearly foreseeable from 1998".


  • The approach taken by the judge in Robbins follows that which courts have tended to adopt in these cases and it shows that even following Berent, Local Authority defendants face a considerable struggle to defend cases on the issues of foreseeability and causation. Although, in many ways, the Claimant's evidence on both issues was not particularly strong, the Council's knowledge of damage to neighbouring properties was a telling point and furthermore it had received a request to remove the tree before the major damage had occurred.
  • Having decided to carry out work in 2004/2005, and indeed having told the Claimant that crown reduction would be carried out, the Council's failure to do so before the severe damage occurred in summer 2006 made the Council's position difficult.
  • There is clearly a balance to be drawn between the environmental interest in retaining a tree, and the likelihood of that tree causing damage if allowed to remain, but the approach of the courts seems to favour property owners.
  • Moreover, following publication of the "Hortlink" report in 2004, those responsible for trees will have to consider carrying out more extensive crown reduction than might previously have been contemplated, so as to be effective, or even the removal of the tree in question.

For further information, please contact John Morrell, Director, on 0207 645 9538 or at

To view the rest of the articles in this Local Authority brief, please click on the titles below:

Vicarious liability: local authorities and foster carers

Case law update: highways

Case law update: other local authority litigated claims

Counter Fraud Focus: gathering your evidence

Interview: Wayne Rigby, Risk and Insurance Manager, Doncaster MBC

This information is intended as a general discussion surrounding the topics covered and is for guidance purposes only. It does not constitute legal advice and should not be regarded as a substitute for taking legal advice. DWF is not responsible for any activity undertaken based on this information.