eBriefs
Japanese Knotweed: do you still need to worry?
1st August 2022
One of the most common reasons for garden-related legal action is when Japanese knotweed has taken root.
This invasive and fast-growing plant has roots that can spread several metres and can regenerate from small amounts of root material. Removal of knotweed from land usually involves specialist waste disposal. Contaminated soil and plant material from Japanese Knotweed is classified as hazardous waste, and landowners can be fined up to £5,000 or sent to prison for two years if they allow knotweed to spread in the wild.
Historically, the presence of Japanese Knotweed has resulted in an effect on property values and been the source of several disputes. Knotweed has a bad reputation and concerns about the effects of a knotweed infestation have been rife.
A landmark Court in 2017 established that landowners are responsible if they do not prevent knotweed from spreading from their land to adjoining properties. A group of homeowners in South Wales took action against Network Rail after Japanese knotweed grew into their garden from adjoining railway sidings. Despite there being no physical damage, the court ruled in the homeowners’ favour, saying that the presence of Japanese knotweed was sufficient reason for compensation as it had the potential to seriously affect the market value of a property. The judgment was later upheld by the Court of Appeal.
A 2019 case saw a £50,000 compensation pay-out being made after a surveyor failed to tell a buyer about knotweed at a £1.2 million flat, and in one of the latest cases to reach the courts, the owners of a property in northwest London are claiming £250,000 in compensation from their neighbours. They say that a failure to deal with knotweed has devalued their house, which would otherwise now be worth £1.67 million.
Some mortgage lenders have historically restricted their lending on properties that are affected by knotweed, and homeowners may have found themselves having difficulty in selling or finding the value of property significantly reduced.
There may well be a shift in attitude in future. This year the Royal Institute of Chartered Surveyors (RICS) issued new guidance for valuing property where knotweed is present. The RICS guidance, produced for its surveyor members on how to assess the impact of any infestation, suggests that previous parameters were overly strict. The new guidance indicates the end of the so-called “seven metre rule” which gave rise to the understanding that a mortgage should not be offered if knotweed was present within 7 metres of a property boundary. It also marks a shift in stance on managing any infestation, from seeking permanent removal to achieve eradication, towards management of the problem through herbicides.
Dispute Resolution Solicitor, Jo Readman of Sharmans commented: “The RICS guidance is overall a positive step for the owners of properties affected by Japanese Knotweed. It is hoped that in future, public perception of the weed becomes more measured and proportionate. However, until we see clear evidence of a greater acceptance of knotweed from surveyors and lenders, it is still sensible to keep on top of any infestation, whether on your own property or in a neighbouring garden.
“If it’s on your land, there is no legal requirement to remove Japanese knotweed though you should ensure that it does not cause a nuisance to neighbouring landowners. You may also want to put a management plan in place to avoid a bigger problem in future such as potential claims against you, difficulties selling your property, or problems caused by the knotweed itself. When a property is being sold, part of the conveyancing process includes a comprehensive questionnaire for the owner, which includes asking about Japanese knotweed on the property.
“Where you know knotweed to be present on adjoining land, you should ensure this is brought to the attention of your neighbour and you should request they ensure it does not spread over the boundary. If there is evidence of it crossing the boundary to your property, you may have grounds for a nuisance claim, which may involve a request for an eradication programme and guarantees from a specialist company, or compensation.”
Jo added: “Your home is usually your biggest asset, so it’s important to protect it - whether you’re planning on moving soon or not.”
This is not legal advice; it is intended to provide information of general interest about current legal issues.