Sign up, keep in touch
Receive our latest updates, alerts and training and event invitations.
The Court of Appeal has recently confirmed in Davies v Bridgend County Borough Council [2023] EWCA Civ 80 that property owners may claim damages in private nuisance for diminution in value of their premises following encroachment of Japanese knotweed from neighbouring land.
In summary, successful claims in private nuisance must demonstrate that there has been an unreasonable violation of a property owner’s rights in relation to their land. The interference will either take the form of encroachment (e.g. tree roots extending across a boundary), direct physical damage (e.g. acidic industrial emissions damaging washing), or interference with quiet enjoyment (e.g. noise or smell). The claimant must also be able to demonstrate that harm or objective loss of amenity has been caused as a result.
Knotweed had spread from the council’s land to Mr Davies’ adjacent land some time before 2004. In 2012, the Royal Institution of Chartered Surveyors (RICS) published a report that described the difficulties that knotweed can cause. In the County Court, the District Judge held (and neither party contested) that the council had breached its duty in private nuisance to Mr Davies from 2013 until 2018, by which point the council had put in place a reasonable and effective programme to treat the knotweed.
The District Judge did not accept the council’s argument that, because the encroachment started before the council was found to have breached its duty, it could not have caused the nuisance. Instead, the District Judge found that the persisting encroachment amounted to a continuing breach.
The District Judge, however, refused to allow Mr Davies to claim £4,900 representing the diminution in value of his property after the knotweed had been treated. In support of this, the District Judge relied upon the Court of Appeal decision in Williams v Network Rail [2018] EWCA Civ 1514 where it was held that it was wrong in principle to conclude that the presence of knotweed on the defendant’s land within seven metres of the claimants' properties was an actionable nuisance simply because it diminished the market value of the claimants' respective properties.
Mr Davies’ appeal was dismissed by the Circuit Judge who stated that the decision in Williams was authority that pure economic loss (i.e. loss not resulting from any physical damage or interference with a person or their property) including diminution in property value is not recoverable in private nuisance claims.
Mr Williams subsequently appealed to the Court of Appeal, which held that the lower judges had drawn the wrong conclusion in relation to the issue of diminution of value.
Giving the leading judgement, Lord Justice Birss stated that the key point from Williams was that, where knotweed is on the defendant’s land, even if it is close to the boundary and at risk of invading the claimant’s land, any reduction in market value of the claimant’s land which this causes does not result from physical damage nor from interference with the claimant’s property and, therefore, does not amount to a nuisance.
However, as in Mr Davies’ case, where the constituent elements of nuisance have first been satisfied (e.g. there has been encroachment), then a claim for diminution of value could succeed. Whilst he agreed that a trivial or de minimis encroachment of knotweed is not enough to establish nuisance, it was not necessary for the claimant to prove a risk to structures on the land or that there is a prospect of improving or altering the property that the knotweed interferes with, or anything else.
Lord Justice Birss also dismissed the council’s argument that its breach had not caused the nuisance and stated that the fact the encroachment was historic was no answer when there was a continuing breach of duty as a result of persisting encroachment. Viewed in 2018, after five years of breach of duty by the council in failing to treat the knotweed on its own land adequately, the knotweed was still encroaching on Mr Davies’ land and the harm persisted in 2018 precisely because the nuisance was a continuing breach.
Whilst it is still much maligned, Lord Justice Birss noted that knotweed is not the “bogey plant” it was once thought to be. In fact, current RICS guidance dispenses with the previous approach of treating seven metres as the threshold for concern regarding the proximity of knotweed to property. Instead, a more nuanced, evidence-led approach is favoured which adopts an assessment process which reflects the actual impact of an infestation at a property. Nevertheless, lenders and, therefore, purchasers and owners remain alive to the risk posed by knotweed to property value and the Court of Appeal’s decision provides some welcome clarity that diminution of value is recoverable in nuisance claims.
For more information on public nuisance claims, please contact Rob Biddlecombe or a member of our Planning and Environmental team.
Receive our latest updates, alerts and training and event invitations.