14 August 2018

Japanese Knotweed - A growing nuisance

Japanese knotweed has long been regarded as something of a nuisance and not a species that you would welcome as being identified on your property. However, following a recent ruling by the Court of Appeal in Network Rail Infrastructure Limited v Stephen Williams, Robin Waistell, the Court has now confirmed that the presence of Japanese knotweed can in fact be an actionable nuisance in the legal sense of the word for which a landowner can be liable to a neighbouring property owner in the event that its presence interferes with the neighbour's use and enjoyment of his/her land.

This was a case brought by two owners of land whose properties abutted the railway embankment. The embankment, owned by Network Rail, was infected with Japanese knotweed. Japanese knotweed is classed as an invasive species and is a hardy, bamboo-like perennial plant which grows quickly and strongly and spreads through its underground roots and rhizomes (which are similar in their effects to roots, being underground stems, which themselves produce fine, white, hair-like roots). Once identified, it is not easy to eradicate and requires consistent and aggressive treatment, often consisting of a combination of excavation and disposal of affected soils, installation of a root barrier membrane and chemical spraying. In this case, the two property owners brought claims in private nuisance on the basis that the Japanese knotweed on Network Rail's land had caused damage to their properties. The Recorder in the County Court found in favour of the property owners, and in explaining their reasoning, they seemed to suggest that that it is possible for a claim to succeed despite there not actually being any physical damage to the properties.

Network Rail appealed the decision to the Court of Appeal. The Court of Appeal agreed with the ultimate decision of the County Court and upheld it, but for different reasons. The judgement provides a helpful reminder of the law relating to private nuisance and somewhat reins in the County Court's decision in relation to claims for 'pure economic loss'. The Court of Appeal said that the decision of the County Court was more than an incremental development of the common law principle, and actually amounted to a "radical reformulation of the propose and scope of the tort".

However, in their judgement the Court of Appeal said that the presence of Japanese knotweed imposes an immediate burden on the owner of the land as there is both an adverse effect on the ability and cost of developing the land should the owner wish to do so, and the owner's ability to use and enjoy the land is undoubtedly affected. In that sense, the Court of Appeal felt that this was a classic example of interference with the amenity value of the land.

This decision will be of concern to landowners with Japanese knotweed on their properties as it is clear that the very fact that Japanese knotweed is so difficult to eradicate and carries the risk of damage to property may be sufficient for a claim in private nuisance by a neighbour for interference with their use and enjoyment of their land (not to mention the fact that lenders are cautious when considering lending on properties with Japanese knotweed). Landowners should ensure that they carry out routine surveys, particularly landowners with large portfolios who may not be in physical occupation of their property, so that they can identify areas suffering from the presence of Japanese knotweed. It is then vital that landowners take reasonable and appropriate steps to eradicate it, putting in place professional treatment plans to ensure that they are doing everything they should be to avoid interference with neighbouring properties. It will no longer be an option to ignore it, as doing so could leave landowners open to claims of a similar nature.

Juliet is an associate in our Residential Property team.

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