The root of the problem

A High Court ruling in a case where tree roots were causing property subsidence will be welcomed by local authorities, writes Andrew Plunkett.

In GA Berent v (1) Family Mosaic Housing (2) Islington LBC [2011] EWHC 1353 (TCC) the court held that a local authority, or other relevant party, would only be liable for property subsidence damage caused by their tree(s) if they were aware (or ought to have been aware) that there was a "real risk" that their tree(s) would cause damage to the specific property in question.

This case potentially makes it more difficult for claimants to establish that any damage was foreseeable, and therefore for claimants to establish their claim in either nuisance or negligence. It represents, potentially, a significant step in favour of local authorities and other public landlords.

Summary of facts

The claimant, Mrs Berent, owned a residential flat in Islington (the property). The first defendant, Family Mosaic Housing (Mosaic), a housing association, owned a neighbouring property, within which stood a London plane tree subject to a TPO (Tree Preservation Order) imposed by the second defendant, Islington LBC (Islington). Islington was also responsible for maintaining two plane trees in front of Mrs Berent’s property (the street trees). The property was built on a layer of ‘made ground’, mainly clay, underlain by London clay.

The claim

The claimant alleged that the trees of both defendants had caused subsidence damage to the property. The major damage was complete by spring 2004.

There were substantial delays in notifying the defendants that their trees were implicated. Islington was not notified until April 2009. Both defendants gave notice of their intention to remove the trees in February 2011.

The following points emerge from the judgment.

Foreseeability

It is established law that neither negligence nor nuisance are ‘strict liability’ offences: the damage must have been ‘reasonably foreseeable’ by the defendant.

Islington argued that damage to the claimant’s property was not foreseeable given its regular regime of tree maintenance. The question of whether a particular property subsided depended upon many factors, including the depth of the foundations, and other variables. It was not possible to foresee that subsidence would occur to a particular property.

Arboriculturalists for both parties agreed that it was not possible to predict which trees would cause damage to buildings. The only way to remove the risk of damage entirely would be to remove the trees.

The judge held that a responsible local authority in such an area: “… could not reasonably contemplate the desertification of such a neighbourhood by wholesale tree felling to avoid a possible risk of damage.”

Taking into account the delay in notifying Islington, he found that there was no basis for supposing that Islington knew, or ought to have known, that there was a ‘real risk’ that the trees would cause damage to the claimant’s property until March 2010. Failure to remove the trees by April 2010 amounted to a breach of duty.

As the defendant was not in breach of duty until after the major damage had occurred, it was not liable for the cost of repair, only for loss of amenity and gross inconvenience from April 2010 onwards – a relatively small sum.

Other points

On causation, the judge affirmed the test in Loftus–Brigham v London Borough of Ealing [2003] EWCA Civ 1490, ie, that the trees need not be the sole cause of damage but must be an ‘effective and substantial’ cause in order to establish liability.

On the duties owed by public landlords (as against local authorities), he held that as ‘prudent public landlords’ Mosaic could be expected to have a similar degree of arboricultural knowledge to a local authority.

Its knowledge affected the extent of its duty to maintain the relevant tree(s). He saw no reason to distinguish between it and the local authority so far as abatement and tree felling were concerned.

Comment

Previously the courts have effectively accepted that, if it was foreseeable that some buildings in a tree-lined street maintained by a local authority would or might suffer subsidence damage, that would satisfy the foreseeabilty test required in both nuisance and negligence.

This case is the first to recognise that, given that it is not possible to predict which properties will suffer subsidence (if any), the damage to a particular property is not foreseeable unless the local authority knew, or ought to have known, that there was a ‘real risk’ of damage to the property in question. In this case, the local authority ought not to have been aware of such a risk until after it was notified of the damage, and provided with evidence of causation, by the claimant.

For claimants, this case emphasises the need to contact the local authority (or other relevant party) as soon as damage is apparent, and to provide reasonable evidence that the trees are responsible. Foreseeability for damage which occurs thereafter is unlikely to be an issue.

For local authorities, this case represents a welcome recognition, in legal terms, of the importance of street trees to the local environment.

Andrew Plunkett is a solicitor in the professional indemnity team at national law firm Berrymans Lace Mawer LLP. He can be contacted at This email address is being protected from spambots. You need JavaScript enabled to view it..