At SE Knotweed, we set out what a knotweed encroachment claim needs: proof the plant spread from a neighbour who failed to act after they knew, with recoverable losses usually the treatment cost and interference with the use of your land.
At SE Knotweed, we explain that a knotweed encroachment claim is a private nuisance action brought where the plant's rhizome has spread onto your land from a neighbour who failed to control it, seeking the cost of putting the problem right.
The claim rests on the interference the encroachment causes, not on the mere presence of the plant next door. A survey that maps the spread and identifies the source is the foundation of any claim, and legal advice is essential before you begin.
To succeed you must prove that the knotweed encroached onto your land from the defendant's, that they knew or ought to have known of it, and that they failed to take reasonable steps to prevent the interference, the three elements of nuisance.
Knowledge is often fixed by published RICS and Environment Agency guidance, which the courts treat as the point a landowner ought to have appreciated the risk. The survey supplies the encroachment and source evidence; correspondence supplies the knowledge.
You can usually recover the reasonable cost of treating the encroaching knotweed, the survey fee, and any expense of a barrier or works needed to protect your land, together with damages for the interference with your use of it while the nuisance continued.
What you generally cannot recover is a residual fall in value after treatment, following Davies v Bridgend. We set the recoverable heads out honestly so expectations match the law.
Davies v Bridgend [2024] UKSC 15 limited encroachment claims by holding that a residual diminution in value is not recoverable where the encroachment occurred before the defendant was in breach of any duty, treating that loss as pure economic loss the law of nuisance does not cover.
The practical effect is that a claim recovers the cost of dealing with the live nuisance, not a stigma discount on the price. The diminution page explains the reasoning.
There is a limitation period, but knotweed nuisance is often treated as a continuing wrong that renews while the encroachment persists, which affects when time runs. The precise position depends on the facts and needs legal advice.
Because delay can weaken both the evidence and the claim, the practical step is to survey the stand and put the neighbour on notice promptly rather than assuming there is plenty of time.
You need a survey to bring a credible claim, because it confirms the species, maps the encroachment across the boundary, identifies the likely source and reads the growth, which is the expert evidence a court and the other side's solicitor will test.
Without it a claim is assertion rather than proof. We produce a report written to support a claim, and can liaise with your solicitor on what they need.
You can claim against whoever occupies or controls the land the knotweed spread from, which may be a private neighbour, a council, a housing association or an infrastructure owner such as Network Rail, each of which has faced knotweed nuisance claims.
Public and corporate landowners usually have a reporting procedure, and putting them on notice in writing is often the step that starts their duty. The survey identifies the correct source to name.
Most knotweed disputes settle, because the recoverable cost of treatment and a barrier is usually modest against the expense and risk of a trial, so a negotiated agreement to treat or to pay for treatment often serves both sides.
Whether to settle or litigate is a decision for you and your solicitor on the facts and the offer. Our role is to give the survey evidence and the costed treatment figure that any settlement is built on.
Tell us the address and what a surveyor flagged. We confirm the plant, record the RICS category and set out the figures.