This case concerned a nuisance claim brought by a landowner, Mr Davis against Bridgend County Borough Council (the Council) to recover damages for loss suffered as a result of the encroachment of Japanese Knotweed (Knotweed) from the Council's land.
Knotweed on the Council's land had encroached onto a terraced house and garden which was subsequently purchased by Mr Davis in 2004.
It was accepted that it was not until 2013, when information about Knotweed became publicly available, that the Council should have been (or were) aware of the risk of damage and loss of amenity caused by the Knotweed to Mr Davis' property. It was also accepted that they were in continuing breach of their duty in private nuisance from this time until they implemented a Knotweed treatment programme in 2018.
The Court of Appeal had previously held that where the value of a claimant's land was diminished because of interference with the quiet enjoyment or amenity of their land due to non-trivial, physical encroachment of Knotweed from the defendant's land then damages for diminution in value were recoverable and were not, as the lower Courts had held, pure economic loss. This was not challenged by the Council.
However, the Council appealed to the Supreme Court specifically to challenge whether the diminution in value to Mr Davis' property was caused, as a matter of fact, by the Council's breach of duty in private nuisance. The Supreme Court held (overturning the Court of Appeal's decision on this point) that the diminution in value was not caused by the Council's breach as Knotweed had been present since 2004, so any diminution in value had occurred long before the Council's breach of duty between 2013 and 2018. The diminution in value would have happened in any event and there was therefore no causal link between the Council's breach of duty and the loss being claimed.
The judgment is an interesting summary of the law on factual causation in the context of a nuisance claim and provides useful clarity for landowners on both sides of these unwelcome disputes in relation to liability for the historic spread of knotweed.