Japanese Knotweed Case-law Update

March 6, 2017

Japanese Knotweed is on the rapid rise across Northern Ireland, causing increasing problems for developers and private homeowners. Since its introduction to the UK in the 19th Century it has spread ferociously with the ability to penetrate concrete and tarmac and cause structural damage to buildings. Many homeowners have encountered extreme difficulty in selling their property owing to the reluctance of mortgage providers to lend on homes that have been affected by, or are in close proximity to an infestation of Japanese Knotweed.

A case involving Japanese Knotweed, heard by Cardiff County Court on 2 February 2017, may prove to have significant implications for landowners and homeowners across the UK. In this case, Japanese Knotweed growing on land owned by Network Rail was in close proximity to residential properties. Two neighbours brought civil proceedings against Network Rail as their homes were affected. Their homes had fallen in value and were difficult to sell as Network Rail had not taken sufficient action to control the Japanese Knotweed growing on their land. The Judge found that their properties had suffered from encroachment and the presence of Japanese Knotweed interfered with use and enjoyment of their land. The Judgment discusses three types of nuisance:

  1. Encroachment with no physical damage
  2. Encroachment with physical damage
  3. Loss of enjoyment

The court explained that the presence of Japanese Knotweed on the neighbouring land was an actionable interference with the use and enjoyment of the homeowner’s property on the basis that it interfered with the individual’s ability to realise the full market value for the property. As a result, the homeowner was awarded damages for the cost of treatment and the loss in value of his property after the treatment had been carried out. The Judge stressed that if treatment did not take place then it would be a continuing nuisance and the claimant could come back before the court seeking further damages.

The significance of the case is found in the imposition of a positive duty on landowners to ensure that Japanese Knotweed on their property is not preventing neighbouring owners from being able to sell their property for market value. Prior to this judgement landowners have not been legally required to control or remove existing established areas of Japanese Knotweed. The only prior recourse was an attempt to reach an amicable agreement with the neighbouring landowner, but any control works undertaken would have been at their discretion. If unresolved, this would become a civil matter between landowners however this has been a legal grey area until now.

This case goes some way towards helping to deal with the difficulties faced by individuals whose property is affected by Japanese Knotweed on an adjacent property. If you require any further advice in relation to difficulties faced by Japanese Knotweed on your property or on neighbouring property please do not hesitate to get in contact.

This article has been produced for general information purposes and further advice should be sought from a professional advisor.