Are you buying or selling a property affected by Japanese knotweed? Or perhaps you have bought a house that since discovered Japanese knotweed?

What is Japanese Knotweed?

Japanese Knotweed was introduced into the UK by the Victorians, as an ornamental plant. However, it has long been considered as a highly invasive, non-native species. It is also incredibly hard to eradicate.

Japanese Knotweed can grow up to 10cm per day. This extreme growth rate allows the plant to cause damage to building structures and substructures by targeting weak points, such as cracks in the walls, and attempting to grow through them.

Japanese Knotweed has therefore posed a real issue for buyers, sellers and owners of property. Its presence has significantly affected the value of some property and consequently the owner’s ability to sell, mortgage or insure it. Currently, if Japanese knotweed is found within 7 metres of a property, it should be reported to prospective purchasers’ and their lenders, who in turn may refuse to lend, causing the sale and purchase chain to collapse. There are an estimated 1.45 million properties in the UK, affected by Japanese Knotweed.

Japanese Knotweed Laws

Did you know that The Wildlife and Countryside Act 1981 makes it an offence to “plant or otherwise cause Japanese knotweed to grow in the wild”? Furthermore, the Environmental Protection Act 1990 stipulates that soil or plant material contaminated with Japanese knotweed is classified as “controlled waste” and must be disposed of at licensed landfill sites.

Japanese Knotweed – the new guidance

RICS (The Royal Institution of Chartered Surveyors) have been working alongside the Department for Environment, Food and Rural Affairs (DEFRA) and others, to re-evaluate the stance taken by professionals within the property industry.

Japanese knotweed places an excessive burden on the UK housing market, creating fear and nervousness amongst buyers, sellers and lenders. RICS has stated this fear has led parties to residential property transactions to become “unduly risk averse”. Currently, “reality does not mirror common public perception”.

New draft guidance was issued by RICS for consultation at the end of June 2021 and the consultation period ended on 3 August 2021. The draft guidance can be found on the RICS website and the final version is intended to be issued later this year.

The new guidance is expected to be fairly optimistic about the presence of Japanese knotweed. The emphasis now appears to be control rather than eradication.

The draft guidance confirms that while the plant is capable of causing damage, there is little chance of it damaging structurally sound buildings. RICS have also suggested reducing the distance at which knotweed could have an influence on a property. A surveyor/valuer will now only be required to report knotweed if it is 3m or closer to the property boundary (except when there is a wider infestation which may have implications in the future). This is a very different approach to the well-established 7 metre rule that has been standard practice for many years.

The draft guidance now also shifts the advice that professionals should be giving their clients. Instead of recommending costly excavation of the plant, professionals should now recommend that control and management is the best option for homeowners and purchasers.

The draft guidance is intended to encourage a more balanced approach and reduce the stigma surrounding Japanese knotweed. The new approach may even prevent the disproportionate devaluing of properties, where the plant is present.

RICS does recognise that lenders have their own processes in these transactions, but nevertheless is seeking to provide a framework that they hope lenders will consider when making decisions on knotweed-related mortgages.

What should I do if I discover Japanese knotweed?

This latest guidance is being welcomed by professionals, within the property industry. However, if you identify or suspect Japanese knotweed is present at one of your properties, we recommend you seek advice from specialists on how to manage the plant.

You should also seek legal advice. Unfortunately, property disputes are common when a party refuses to treat or inadequately treats the rapidly growing plant. You may also have claims against professionals such as, surveyors who fail to identify Japanese knotweed and report it.