A tree belongs to the owner of the land on which it grows even if its branches or roots extend over or under adjoining land.
Therefore, the owner of the land on which the tree has been planted will be liable for any foreseeable damage caused to neighbouring structures.
Damage caused by trees may be direct, or indirect, but it is often difficult to detect problems underground. Direct damage may occur when a part of a tree makes contact with, and displaces, part of a structure or intrudes into pipes and drains.
Indirect damage may be caused when tree roots extract moisture from the soil. Some soils, such as clay, reduce in volume as a result, causing the foundations of buildings to subside.
The likelihood of this occurring will depend on factors such as the size, species and proximity of the tree to the structure in question, the type of soil in the locality, the depth, type and quality of the foundations of the building and also on local climatic conditions.
Robbins v Bexley London Borough Council [2012] EWHC 2257 (TCC) concerned tree root damage caused by a tree in a row of mature Hybrid Black Poplars growing in a park. The council argued that it had a duty to act only where there was a reasonably foreseeable risk of damage.
The tree was approximately 30 metres away from the rear extension to a house which suffered the damage.
The experts had found a single poplar root on the property and none in the foundations of the extension.
However, evidence from the council’s files dating back to 1998 showed that the council knew that roots from the poplars had been found at distances in excess of 30 metres from the trees.
In addition, the owners of other properties had made claims in respect of tree root damage. It was also reasonably foreseeable that subsidence might well occur if roots were to grow under relatively shallow foundations, such as those often used when building extensions in the 1960s and 1970s.
Consequently, the council should have had a cyclical tree maintenance programme in place, and should have ensured that its contractors had stuck to it, which would probably have prevented the damage that occurred.
However, the court refused to criticise the council for its failure to take further radical action immediately after the publication of new research in 2004. The judge observed that local authorities cannot be expected to know about, let alone react to, research as soon as it is published.
It would have been reasonable to allow the council at least 12 months to consider the material and then, if appropriate, to modify its policies.
That period might be longer in other cases, depending on precisely when in a financial year the research becomes available, especially if an authority has entered into contracts for work programmed for more than a year ahead.
The decision shows that liability will depend on the facts of each individual case, but highlights the importance of inspecting trees on a regular basis and of carrying out cyclical work to prevent problems.
Allyson Colby
Property Law Consultant