Recent legal battles regarding Japanese Knotweed have resulted in property owners blighted by the plant’s presence winning compensation.

A purchaser of a property with Japanese knotweed in the garden that was not declared in the property information form has successfully sued the former owner for damages and legal costs of £200,000.

The purchaser, Jonathan Downing, claimed that the former owner, Jeremy Henderson, misrepresented the state of the property before purchase. On the Law Society’s TA6 Property Information Form, which must be completed by all sellers, Henderson had answered ‘no’ to the question that asked if the property had been affected by knotweed. Henderson argued that he reasonably believed he was telling the truth whereas Downing argued that he could have answered ‘not known’ on the form.

Henderson must pay £32,000 in damages and Downing’s legal costs of up to £95,000. His own legal fees were estimated at almost £100,000.

In another case, a homeowner has been allowed to claim compensation after Japanese Knotweed spread to his garden from an adjacent cycle track owned the local authority.

The case went all the way to the Court of Appeal where it was ruled that although work had been completed to remove knotweed from the site ‘as best as it can be’, there had been a residual diminution in value of the property, also called blight to the value of £4,900.

The decision by the Court of Appeal now allows property owners to claim damages when their property is devalued from the stigma left by Japanese Knotweed that spreads from a neighbouring property even after it has been treated.