There is no actionable nuisance caused by Japanese knotweed on a defendant’s land simply because it diminishes the market value of the claimant’s land – this is pure economic loss. However, where there is damage leading to a diminution in value, consequential on the nuisance, such loss is recoverable.
The Court of Appeal has allowed a second appeal by the claimant in Davies v Bridgend County Borough Council [2023] EWCA Civ 80. The case concerned property in Dinam Street, Bridgend, Wales, acquired by the appellant in 2004, which adjoined land owned by the respondent, the local council.
The appellant brought a claim in nuisance against the respondent for knotweed growing on the respondent’s land which encroached onto his land.
The judge found that there had been knotweed on the respondent’s land for more than 50 years and that it was likely it had spread onto the appellant’s land before he acquired it in 2004. The respondent was in breach of duty owed to the appellant as a neighbour through persisting encroachment between 2013 and 2018 when a reasonable and effective treatment programme started.
The appellant claimed damages under various heads, all characterised as aspects of diminution in value of the property, including for the cost of treatment, a sum for disturbance and inconvenience and £4,900 for the residual diminution in value of the property or “blight” remaining after treatment of the knotweed. The judge held that all of the claims were irrecoverable, and dismissed the claim citing Williams v National Rail [2019] QB 601 as authority.
The appeal focused on the diminution in value which the appellant claimed was consequential on the nuisance found. The Court of Appeal decided that Williams had been misunderstood in the lower courts. There is no actionable nuisance caused by knotweed on a defendant’s land simply because it diminishes the market value of the claimant’s land. Policy reasons characterise such a claim as one of “pure economic loss”.
However, once the “natural hazard” of knotweed rhizomes is present on the claimant’s land its quiet enjoyment or the amenity value of the land has been diminished. That amounts to damage for the purposes of the elements of the tort of nuisance which is a result of the physical interference. If consequential residual diminution in value can be proved, damages on that basis can be recovered. The appellant was entitled to recover damages of £4,900.
Louise Clark is a property law consultant and mediator
