The Court of Appeal in England and Wales has ruled that householders can claim for the reduction in value to their property caused by Japanese knotweed, where the plant has spread from a neighbouring property. 

Stephen Williams and Robin Waistell both live in Maesteg, South Wales, and their properties back onto a path owned by Network Rail leading to an embankment next to the rail line. On the embankment is a large stand of Japanese knotweed which had been present for at least 50 years, and which had begun to encroach on their respective properties. The presence of Japanese knotweed within seven metres of a building will significantly affect the ability of a homeowner to obtain a mortgage, and thus affects the marketability of the property.

Claims were issued against Network Rail in private nuisance on the basis that the weed had (1) encroached on their properties, and (2) caused a loss of amenity in respect of the properties by reducing their market value. At first instance, the court had held that the reduction in value of the properties was of itself and actionable nuisance and therefore found in favour of the claimants. Network Rail appealed. 


The Court upheld the decision of the judge at first instance to rule in favour of the home-owners. They did however make clear that this was not simply because the market value of the properties had been reduced. The purpose of claims of ‘nuisance’ is not to protect the value of land purely as a financial asset: it is designed to protect the amenity value of the property. In consequence, the first-instance judge’s justification for the award of damages could not stand. 

The Court instead found that the encroachment of knotweed had adversely affected the homeowners’ ability to enjoy and use their land. Its presence “imposes an immediate burden on the owner of the land in terms of an increased difficulty in the ability to develop, and in the cost of developing, the land, should the owner wish to do so”. It therefore found that the homeowners were entitled to compensation.

The Future 

This is an English case, and the law on nuisance is different in England and Wales. Nevertheless the case might influence the approach of Scottish courts in the future. Whereas previously the general view may have been that no pro-activity was required on the part of owners with the misfortune of knotweed, it may be that the law develops such that aspects of positive action may be required.