Physical damage not necessary for an actionable private nuisance.
The County Court Judge’s decision was that NRI was liable simply because the presence of knotweed on their land was within seven metres of the Claimants’ properties which diminished the market value of the properties.
NRI appealed the decision on the following grounds:
The Court of Appeal dismissed NRI's appeal and upheld in most part the ruling made in February 2017, that NRI had caused an actionable nuisance by failing to control Japanese knotweed.
The Court of Appeal clarified that the purpose of the tort of nuisance is not to protect the value of property as a financial asset but to protect the landowner in their use and enjoyment of the land. The County Court's decision was wrong in so far as it effectively extended the tort of nuisance to a claim for pure economic loss, i.e. diminution.
It was ruled that physical damage, e.g. damage to foundations, was not a necessary requirement as the mere presence of Knotweed rhizomes (roots) in the soil imposed an immediate burden/restriction on a landowner. The Court of Appeal concluded that Knotweed was a classic example of interference with the amenity of land. It is a natural hazard, which if it encroaches on your land will restrict your use and enjoyment by limiting your ability to develop the property and by placing on you an immediate burden to take steps to eradicate it.
The diminution in value claim was essentially dismissed, but only because that was not a recognised head of loss in the tort of nuisance. However, the very same award was allowed to stand on the basis that it fairly compensated the Claimants for their loss of quiet enjoyment and amenity.
It will be interesting to see how any future claims will be quantified.
The full judgement can be found here