Don’t ignore Japanese knotweed: avoid litigation and property disputes

Mon 15th Aug 2022

Dealing with Japanese knotweed early on and in the right way is key to avoiding neighbour property disputes and potentially expensive litigation says Coodes’ solicitor Ben Sidgwick.

As solicitors dealing with Japanese knotweed property disputes, we see first-hand some of the serious consequences of not dealing with this non-native invasive plant species. At Coodes, we have represented clients who have found it on their property or have been affected by Japanese knotweed growing on a neighbouring property.

Homeowners and landowners are warned to take advice early on and seek out specialist treatment, otherwise they could face litigation, expensive claims against them and potentially even criminal prosecution.

What is Japanese knotweed?

Japanese knotweed is a perennial non-native invasive plant species – recognised as a fast-growing weed that spreads extensively and has strong deep stems or roots (rhizomes) which make it particularly difficult to eradicate or treat effectively without professional help.

The plant sends up shoots from springtime which grow rapidly, producing distinctive red coloured bamboo-like canes and flat green leaves and can grow to over two metres tall by the end of the summer, before dying back through autumn ready to grow again the following spring.

The problem with Japanese knotweed

Japanese knotweed can cause significant damage to property. Although it rarely causes structural damage to buildings or foundations, it can damage lightweight structures, freestanding walls, sewage, and drainage systems. It can devalue a property, cause a sale to fall through, influence mortgage or re-mortgage applications and affect obtaining insurance for a property.

Under the Wildlife and Countryside Act 1981, Japanese knotweed is classed as a controlled plant so although it is not illegal to have Japanese knotweed present, it is an offence to allow it to spread if you knew it was there. A reform to the Anti-Social Behaviour, Crime and Policing Act 2014 also allows for ASBOs to be issued against individuals and businesses that do not control Japanese knotweed when they could be ‘reasonably expected to do so’.

Some banks and building societies may refuse to give mortgages on properties affected by Japanese knotweed. If a lender does offer a mortgage, it may be on the basis that you have an independent survey and an insurance-backed treatment plan. Treatment can cost a few hundred pounds to thousands with eradication by excavation often running into tens of thousands of pounds.

New guidance from RICS

Recent changes to guidance from the Royal Institution of Chartered Surveyors (RICS) seeks to dispel myths and misconceptions about what some people perceive as a ‘super plant’ and what can be done to help landowners and homeowners.

This new guidance has moved away from a seven-metre property proximity threshold, in favour of the evidence-based three-metre threshold, so we are likely to see some softening of how lenders approach the issue and how the plant is perceived by the public.

What are your responsibilities?

Fundamentally, there are two types of claims.

One is where is there is Japanese knotweed on a property, this has an impact on a neighbouring property, and this is not dealt with effectively with the landowner failing to treat it properly. This is primarily a private nuisance for an adjoining property owner and disputes between neighbours over Japanese knotweed fall under the civil law.

A recent example of this is where millionaire businessman Christopher Clarke and his partner Louise Kaye are suing their neighbours for £250,000 of ‘damages for nuisance for the encroachment of Japanese knotweed on to their land, from the defendants’ neighbouring land.’ Mr Clarke says the issue has devalued his £1.6 million property by 15 per cent.

There has also been an approved judgment where Network Rail had to pay compensation to homeowners whose gardens were affected by Japanese knotweed spreading from neighbouring railway embankments. The homeowners successfully brought a claim for significant damages based on private nuisance.

The other potential claim is where the seller fails to disclose the issue to the buyer, and they face a misrepresentation action.

When selling your property, you will be asked whether it is affected by Japanese knotweed on the conveyancer’s pre-contract enquiry questionnaire (TA6 Form) and possibly in additional enquiries. As the vendor, it is your responsibility to answer such questions accurately or you could be accused of misrepresentation.

Your purchaser could pursue you for damages based on the cost of removal or treatment of the plant with the property’s value significantly affected as a result.

What can you do?

Do not ignore the problem if you see it in your garden or on your land. You should deal with the issue quickly and get appropriate advice. There is specific Government advice on how to stop the spread and strict rules on how to dispose of Japanese knotweed legally.

Do not try to treat Japanese knotweed yourself – there are specialist professional contractors and consultants who have the right skills and expertise to treat and eradicate. If it is not treated properly, it can grow back.

Do not try and dig it up or disturb it, as this could lead to further contamination and cause it to spread. It is classed as controlled waste under the Environmental Protection Act 1990 and failing to dispose of it according to the Duty of Care Regulations 1991 (amended 2003) may lead to criminal prosecution.

In summary, take advice as soon as you become aware of the issue – although there will be some initial costs for professional help, not dealing with the situation could prove far more costly in the long-term.

For more information and specialist dispute resolution advice about whether there is potential for a legal claim around Japanese knotweed, use our contact us form or call 0800 328 3282.

Mon 15th Aug 2022

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