Supreme Court untangles law on damages for continuing nuisance in Davies v Bridgend County Borough Council

Supreme Court untangles law on damages for continuing nuisance in Davies v Bridgend County Borough Council

On 8 May 2024, the Supreme Court unanimously overturned the Court of Appeal’s decision finding that the diminution in the value of Mr Davies’ land was not caused by Bridgend County Borough Council’s (“the Council”) breach of its duty to treat Japanese Knotweed (“Knotweed”) present on Mr Davies’ land.

Knotweed is an invasive plant which can grow through gaps in properties, causing significant structural damage and reducing biodiversity if left untreated. Classified as “controlled waste”, excavated Knotweed must be disposed of in accordance with the Environmental Protection Act 1990. This not only means that treatment and plans to develop contaminated land can be costly, but also that the value and insurability of property can be affected due to concerns of potential regrowth from lingering knotweed rhizomes in the soil, even after initial treatment. The court measures the resulting loss in the market value of the property as ‘diminution in value’, which they may award to claimants as damages.

Background

Mr Davies purchased a parcel of land adjoining land the Council’s property in 2004. It was established that Knotweed had already spread from the Council’s land to Mr Davies’ land well before his purchase.

In 2012, the Royal Institution of Chartered Surveyors (RICS) published guidance on the issues caused by Knotweed, which should have alerted the Council to the risks to Mr Davies’ land. The district judge at first instance determined that an actionable nuisance arose in 2013 when the Council failed to implement a reasonable and effective treatment programme and their failure to do so interfered with Mr Davies’ enjoyment of his land Private nuisance arises where someone’s action (or in this case inaction) on their own land interferes with another’s enjoyment of their land, whether this be by encroachment or physical damage. As the Council did not begin treating the Knotweed until 2018 it was determined that there was a continuing breach of duty between 2013 and 2018.

In 2023, the Court of Appeal ruled that, although the Knotweed had encroached on Mr Davies’ land before the Council could reasonably be expected to know of the risks, the Council’s subsequent continuing breach made them liable for £4,900 in damages for the residual diminution in property value.

Supreme Court’s Judgment

Key to the Supreme Court decision to overturn the Court of Appeal’s finding was its application of the ‘but for test’. The Supreme Court framed the question as ‘but for the Council’s breach between 2013 and 2018 would the encroachment of Knotweed have caused the diminution in value of Mr Davies’ land’. It was established that the diminution of the value of the land occurred prior to the Council’s initial breach in 2013 due to the presence of the untreated Knotweed. Consequently, the Supreme Court reasoned that the Council’s breach between 2013 and 2018 did not materially contribute to the diminution of the land’s value. The encroachment of the Japanese Knotweed would have caused the diminution in value regardless of the Council’s breach.

The Supreme Court also clarified that, in the right circumstances, property owners suffering from continuing nuisance are able to abate the nuisance and recover their reasonable costs incurred in doing so. However, contrary to the Court of Appeal’s interpretation, diminution in market value does not constitute a reasonable cost capable of recuperation.

Generally, the Supreme Court’s decision is a welcomed re-assertion of the principle that damages for continuing nuisances will not be awarded unless there is a causal link between a breach and the loss. Looking forward, the ruling should provide reassurance to property owners and lenders that unless a claimant can show evidence of a separate diminution in value due to delays or pauses in effective treatment, they are unlikely to be ordered to pay damages for diminution in value if they have treated the initial encroachment. Nonetheless, lenders and insurance companies are likely to continue to require evidence of a specialist mitigation plan when offering services related to Knotweed contaminated land.

For further information please contact: Kenny Friday or Paul Dench

Please note that this information is provided for general knowledge only and specific advice should be sought for individual cases.