Homeowners beware: you may be liable for tree root damage caused to your neighbour's property
The Technology and Construction Court has recently handed down a judgment of some significance for private homeowners and insurers. In the case of Khan and Khan v Harrow Council and Sheila Kane  EWHC 268, Mr Justice Ramsey had to determine whether a homeowner is liable for damage to neighbouring property caused by the roots of trees on their property.
The Claimants in this case were Mr and Mrs Khan who in July 2001 purchased a house in Stanmore, Middlesex ('the Property'). The Defendant was Mrs Kane who owned a neighbouring property which had a number of trees on its grounds.
The Claimants noticed damage to the Property in September 2006. An initial investigation and monitoring was carried out by their insurers. A report was produced in July 2007 identifying a Lawson Cypress hedge ('H1') in Mrs Kane's property as having "the potential to be a significant factor in the current damage". The report recommended that a section of H1 was removed to achieve a minimum clearance of 5m to the Property. A further investigation was carried out in relation to an oak tree at the front of the Property ('T2') and an oak tree at the front of Mrs Kane's property ('T1') recommending that they were not permitted to increase in size.
A further report produced in June 2009 confirmed that H1 was the most likely cause of the damage and recommended that all Cypress trees within 5m to the right of the property were felled. The Claimants then asked Mrs Kane to remove the relevant sections of H1 which she did shortly afterwards.
A further damage occurred at the Property and an additional report noted that one or both of T1 and T2 were the material cause of that damage. Both trees were subsequently felled.
The claim was initially brought against the London Borough of Harrow in March 2011. This was settled shortly afterwards. The Particulars of Claim were amended in November 2011 to include the claim against Mrs Kane in nuisance and negligence for the damage caused by H1 and T1.
- The Court had to determine the following key issues:
- Was the damage to the Property from T1 and H1 reasonably foreseeable?
- Did Mrs Kane act reasonably to prevent the damage?
- Was it relevant when Mrs Kane was put on notice of the risk of damage?
- Were the Claimants contributory negligent or (in the alternative) did they fail to mitigate their loss?
Handing down the judgment in the case, Mr Justice Ramsey held that:
- Mrs Kane had no actual knowledge in relation to any risk of damage but the general risk of damage ought to have been known to a reasonably prudent landowner. The question was whether the particular risk posed by H1 and T1 was reasonably foreseeable. Based on the evidence, a reasonably prudent landowner with trees on their land would have appreciated that there was a real risk (rather than a mere possibility) that H1 might cause subsidence damage due to its size and proximity to the Property. No such foreseeability was present in relation to T1, based on its characteristics.
- The risk of tree root damage by H1 being significant, no reasonably prudent landowner would have considered it right to neglect it. Mrs Kane failed to take the appropriate steps to eliminate the risk of subsidence damage caused by H1.
- The question of notice was not relevant in this case because:
- the risk of damage caused by H1 was foreseeable and therefore no notice was required to impose liability on Mrs Kane;
- the risk of damage caused by T1 was not foreseeable and Mrs Kane took action as soon as she was put on notice so she was not liable for any continuing nuisance;
- there was no argument in this case that lack of notice had made any remedial works irrecoverable.
- It would have been reasonable for the Claimants to have informed Mrs Kane about the risk of damage at an earlier stage and they were therefore 15% responsible for the damage caused.
Mr Justice Ramsey concluded that Mrs Kane was liable in nuisance for the damage caused by her failure to eliminate the risk of subsidence damage caused by the roots of H1, but not for the damage caused by T1. She was liable for 85% of the damage caused by H1, 15% being reduced due to the Claimants' contributory negligence. The damages awarded included an amount for the remedial work carried out together with the loss adjuster's fees, and general damages for distress and inconvenience.
Mr Justice Ramsey noted that the question of whether the risk of tree root damage was reasonably foreseeable would largely depend on the particular facts of each case. Nevertheless, his decision may have wide implications for:
- private homeowners who would now need to keep a close eye on any trees within their property which may cause damage to a neighbouring property; and
- building insurers who may need to consider whether they should increase their premiums.
Although Mr Justice Ramsey was cautious not to place too high a burden on landowners and emphasised that the relevant standard was not that of the reasonably prudent arboriculturalist, it would be difficult for a landowner to discharge his/her duty without some specialist knowledge. The factors which may be relevant include:
- the presence or absence of actual knowledge of any risk of damage;
- the proximity of the relevant trees to any neighbouring property;
- the size and condition of the relevant trees;
- whether or not any of the relevant trees has a dominating position;
- whether or not the landowner's insurance policy covers them against subsidence damage;
- whether or not the landowner has general knowledge about risk of subsidence through media (although this would not suffice on its own).
In any event, the best option for landowners will be to instruct a specialist.