FREE CHAPTER from ‘A Practical Guide to the Law in Relation to Japanese Knotweed and Other Invasive Plants – Second Edition’ by Tom Carter

CHAPTER ONE – THE ELEMENTS OF A NUISANCE CLAIM

To establish a claim in nuisance, a claimant must show that the defendant owed them a duty of care, was in breach of that duty and the breach of duty caused the claimant loss.

Before getting onto those points, however, the claimant must first show that there is something which is capable of being an actionable nuisance in the first place. The aim of this chapter is to consider what needs to be satisfied for a claimant to show a nuisance from the presence of Japanese knotweed.

To establish a nuisance, a claimant must show that:

  1. There is Japanese knotweed within the boundaries of their land;
  2. It has encroached onto their land from the defendant’s land.

Unlike claims for encroachment of tree roots, there is no need to show physical damage in order to establish a nuisance in relation to Japanese knotweed.

This was established in the leading case on liability for Japanese knotweed in the Court of Appeal’s decision in Williams v Network Rail Infrastructure Ltd [2019] QB 601, [2018] EWCA Civ 1514.

This was a claim by two neighbours, both of whom owned houses that backed onto a railway line owned by Network Rail. There was Japanese knotweed growing on the railway embankment adjacent to their houses. At trial, the Recorder held that knotweed had encroached from Network Rail’s land onto the claimants’ land but that there was no physical damage.

The Recorder considered the three types of nuisance set out by Lord Lloyd in Hunter v Canary Wharf [1997] AC 655 at 695C:

  • Nuisance by encroachment on a neighbour’s land;
  • Nuisance by direct physical injury to a neighbour’s land;
  • Nuisance by interference with a neighbour’s quiet enjoyment of their land.

He held that on the authorities, a type 1 nuisance nevertheless required physical damage. On that basis, he held that there was no actionable type 1 nuisance.

A type 2 nuisance was never in issue because there was no evidence of physical damage.

The Recorder did find an actionable type 3 nuisance. He held that the presence of Japanese knotweed on the defendant’s land, close to the boundary with the claimants’ land, was sufficient to interfere with their quiet enjoyment of their land because it may nevertheless affect the sale price and this was an interference with their quiet enjoyment of the land.

In the Court of Appeal, the Master of the Rolls warned against a rigid categorisation of nuisance claims in this way (para 41) but to explain the decision, I will use the type 1 and type 3 analysis above. The Court of Appeal took the opposite approach to the Recorder and held that there was a type 1 nuisance but not a type 3 nuisance.

The Court of Appeal held that unlike tree roots, Japanese knotweed is in itself a hazard and that it will diminish the amenity value of land even without physical damage. On that basis, a claimant need only show the presence of knotweed on their land. At para 55 it was said:

“Its presence, and indeed the mere presence of its rhizomes, imposes an immediate burden on the owner of the land in terms of an increased difficulty in the ability to develop, and in the cost of developing, the land, should the owner wish to do so. As the RICS paper observed, any improvement or alteration of the property requiring the removal of contaminated soil would require disposal of the soil either on site or, more likely, off site by special, and probably expensive, procedures. For all those reasons, Japanese knotweed and its rhizomes can fairly be described, in the sense of the decided cases, as a “natural hazard”. They affect the owner’s ability fully to use and enjoy the land. They are a classic example of an interference with the amenity value of the land.”

And at para 73:

“In short, there is no reason why the legal position concerning nuisance caused by the encroachment of the branches or roots of trees should undermine the right of the claimants in the present case to claim damages for nuisance by reason of the encroachment of Japanese knotweed and its rhizomes from NR’s land.”

It should be noted in respect of the increased difficulty in developing land referred to in para 55 that there was no evidence from either of the claimants about plans to develop the land. It is the difficulty in principle that constitutes the interference.

The Court of Appeal did, however, reject the Recorder’s finding that presence of knotweed on the defendant’s land close to the boundary was enough to establish a type 3 nuisance per para 46:

“The Recorder’s conclusion that the presence of knotweed on NR’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, because of lender caution in such situations, was wrong in principle.”

In the first edition of this book, I said that this paragraph had caused confusion amongst some lawyers who took it as authority that a claimant cannot recover damages for diminution in value at all. I said that this was wrong and discussed this issue in Chapter Six.

What I said in the previous edition of this book was held to be right by the Court of Appeal in Davies v Bridgend County Borough Council [2023] EWCA 80. In that case, the defendant argued that the diminution in value was pure economic loss because there was no physical damage, and that the reference to “simply because it diminished the market value” in para 46 of Williams was authority that damages for diminution could not be recovered.

In Davies, Birss LJ said at paras 38 and 39:

“38. In a case in which the knotweed is on the defendant’s land, even if it is close to the boundary and at risk of invading the claimant’s land, Williams holds that the reduction in market value of the claimant’s land which this causes does not result from physical damage nor from physical interference with the claimant’s property and therefore does not amount to a nuisance. Putting a small gloss on the opening words in paragraph 48 of Williams, I would say that the purpose of the tort of nuisance is not simply to protect the value of property. After all Williams itself later recognises that if the value of the claimant’s property is diminished as a result of an interference with the claimant’s quiet enjoyment or amenity, due to physical encroachment of knotweed from the defendant’s land into the claimant’s land, damages including diminution in value of the property will be available. Putting it another way, the reasoning in paragraph 48 of Williams, which the judges below relied on, is nothing to do with recoverability of damages in a case in which the tort of nuisance is complete.

  1. Subject to one further point I would therefore allow the claimant’s appeal and turn to the respondent’s notice. The reasoning at the end of paragraph 19 of the Circuit Judge’s judgment is flawed because once it is accepted that there was damage leading to a loss (the diminution in value) which was consequential on the nuisance, there is no authority that consequential damage to the claimant’s economic interests is irrecoverable.”

The case of Davies subsequently went to the Supreme Court [2024] UKSC 15. The defendant conceded the point about diminution in value being a consequential loss and thus recoverable. Instead, the sole point on that appeal was causation which I will discuss later in Chapter Five.


MORE INFORMATION / PURCHASE THE BOOK ONLINE