In Davies v Bridgend Borough Council [2023] Mr Davis brought a claim in nuisance against the Council as Japanese Knotweed which had been present on the Council's land for a considerable time (some 50 years) was encroaching on Mr Davies' adjoining property which he had bought more recently as an investment in 2004.
The Court of Appeal held (clarifying a previous knotweed decision) that there would be no actionable nuisance caused by knotweed on a defendant's land simply because it diminished the value of the claimant's adjoining land. However, if the value of the claimant's property was diminished as a result of an interference with the claimant's quiet enjoyment or amenity of his property, due to physical encroachment of knotweed from the defendant's land into the claimant's land as in the present case then damages, including diminution in value of the property, would be available.
The Court also considered the issue of causation. In this case, the knotweed was held to have encroached onto Mr Davies' land by at least 2004 but the Council was not considered to have been in breach of its duty of care as a neighbour to treat the knotweed until a reasonable amount of time had passed since publication of a RICS report flagging the difficulties knotweed can cause in 2012. The Council tried to argue that as the damage from the knotweed occurred before any duty of care arose the claim was flawed on causation. This was, however, rejected by the Court on the basis that it was a continuing nuisance and breach of duty as a result of a persistent encroachment and that unless and until the Council treated the knotweed on its land, any attempt by Mr Davies to eradicate knotweed on his own land would have been rendered futile in any event.
The Court awarded damages of £4,900 based on a residual diminution in value and noted that the proportionality of the proceedings having got as far as they did compared to that figure might be questionable, but that the principle in dispute was nevertheless an important one.
The case highlights the ongoing problem of Japanese Knotweed and the need for landowners to be vigilant and act quickly in relation to any treatment works required to prevent encroachment onto neighbouring land.
