Japanese Knotweed: Recoverable Loss and Landowners’ Duty of Care


In the case of Davies v Bridgend County Borough Council, the Court of Appeal has recently overturned an earlier ruling that a reduction in property value caused by an encroachment of Japanese knotweed amounts to an irrecoverable economic loss.

Rather, the court deemed that a residual diminution in house value was a recoverable loss because the defendant did not inform the claimant of the existence of the knotweed, thus breaching its duty of care.

The ruling may lead to a several further claims against landowners.


Japanese knotweed is a highly invasive plant species that is potentially difficult and expensive to remove.

The homeowner had claimed damages against the local authority on the basis that his house value had diminished as a result of knotweed encroachment, which had come from a local council-owned cycle track.

The court of first instance ruled, on the basis of the earlier case of Williams and Waistell v Network Rail Infrastructure Ltd, that there was an actionable nuisance between 2013 and 2018. However, it had dismissed the claim for residual diminution in value because it amounted to a ‘pure economic loss’, which is not recoverable in cases of Japanese knotweed nuisance. Pure economic loss, in essence, is financial damage suffered which does not result from any other physical damage.

In overturning this decision, the Court of Appeal disagreed with the court’s interpretation of Williams. Determining that there can be no nuisance if there is no encroachment of the Japanese knotweed, it was ruled that the reduction in property value should be the measure of damages. The case of Davies was considered to be distinct because of the element of encroachment, as this amounts to a physical interference with the property and, as a result, consequential losses such as diminution in value became recoverable.


Landowners should therefore take immediate action to remove Japanese knotweed, in order to avoid liability for any residual diminution in the value of property caused by encroachment, which had previously been considered irrecoverable.

Know more about how Japanese knotweed will damage your property.

If you have any questions regarding the recovery of diminishing house value and or duty of the landowner in property trading in the UK, please contact us.

*This article is not legal advice but provides a general overview. The specific details of your case will determine the best course of action.