Don’t Get Tied in Knots by Knotweed

March 10th 2023

Japanese knotweed is an invasive perennial weed with a reputation for growing out of control and growing fast! This plant has been a pest to home and landowners since it’s introduction to the British Isles in the Victorian era. The speed and strength with which it grows, and its resilience, has caused problems for foundations, walls, drains among others.

Knotweed has come to the fore in recent weeks because of a significant Court of Appeal judgment. In the case of Davis v Bridgend County Borough Council [2023], the Court held, on appeal, that where Japanese knotweed had crept from adjoining land onto the claimant’s land, not only should the respondent compensate them by way of damages for the pure economic loss, but also for the diminution in value of the property stemming from the knotweed’s interference with quiet enjoyment or amenity.

In essence, this case paves the way for claimant’s to recover not only pure economic loss damages (the cost of repairs to foundations or drains for example caused by the plants root structures), but also for depreciation caused by encroachment of this weed from infested land onto the claimant’s land. Before this judgment, depreciation would be an unfortunate outcome, but not a loss the claimant could seek to recover from by way of damages.

This case highlights the dangers with Japanese Knotweed. Many conveyancers do not want their lay client warranting or representing that the property is free from Japanese knotweed for fear of it being discovered and their client subsequently sued for misrepresentation. However, this case now raises the stakes in terms of financial liability where a landowner has lost control of a knotweed infestation.

Knotweed can give rise to other legal battles, where knotweed is caused to grow (such as by planting or permitting the escape of the plant) into the wild this will be a criminal act/omission, and further when an infestation impacts a community, the landowner could be served with a Community Protection Notice (as a Bristol property developer sadly discovered). Breach of such a notice and failure to control the plant can lead to criminal proceedings.

Therefore, where me might associate this insidious weed with its creeping notoriety for creeping through urban settings, rural landowners should be concerned too. For the lonely house on the hill, this plant may cause minimal damage and may threaten few if any neighbouring dwellings or outbuildings, however with its escape into “the wild” being criminalised, the civil liability gives way to criminal liability.

While the continuing knotweed saga can catch many landowners out, the right advice can head off liability or mitigate loss. Where you think you may have Japanese knotweed on your land, or where you believe your property is under threat of encroaching Japanese knotweed, identifying your options is the safest bet and may put your mind at ease.

Court of appeal ruled homeowner could recover loss of value even if knotweed has been treated