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Japanese Knotweed – a Knotty Problem


Property, Legal Updates

What is Japanese Knotweed?

Imported into Britain back in the nineteenthcentury, Japanese Knotweed is one of the most invasive plants in the UK. It can grow up to 10 cm a day in the summer, spreading quickly by its roots and stems and is very difficult to remove entirely from land as it can regenerate from relatively tiny amounts.

Japanese Knotweed can also be difficult to identify as it looks a lot like many other weeds.

Some characteristics of Japanese Knotweed which may help you to identify it include:

  • Heart-shaped or shield shaped leaves
  • Bamboo like stems (rings round them)
  • An alternating zig-zag leaf pattern
  • Hollow stems with purple speckles
  • Small creamy white flowers during the summer

Why should you be concerned whether your property (or any neighbouring property) is affected by Japanese Knotweed?

  • Japanese Knotweed is invasive and can cause structural damage to buildings, resulting in a negative impact on not just the value and marketability of the property but also it’s insurability.
  • Japanese Knotweed can be time consuming and costly to treat and manage. It is reported that professional treatment of Japanese Knotweed can be very expensive ranging from £2,500 and rising to £30,000 for a major infestation.
  • Historically there has been reluctance from some mortgage lenders to lend where Japanese Knotweed has been identified at a property which can cause a headache for both home owners and prospective buyers.
  • It can lead to criminal and civil liabilities for owners, occupiers and those who handle the Japanese Knotweed if they fail to do so in accordance with the law.

Pre-Contract enquiries and the importance of an appropriate survey and inspection

If you are in the process of taking a long lease or purchasing the freehold of property or land, then you should consider whether there is a risk that the property is or could be affected by Japanese Knotweed. In standard residential transactions the seller is required to provide a completed standard property information form (also known as TA6) which contains an enquiry as to the presence of Japanese Knotweed. In commercial property transactions it is the environmental enquiries which arguably cover the question of Japanese Knotweed.

There is a potential loophole with residential new build properties as developers are not required to complete the property information form which could leave buyers of new builds exposed. It is therefore important to raise specific enquiries if you have concerns that Japanese Knotweed may be present.

In any event it is likely that the seller may not give a definitive response to such enquiries and the onus may be pushed back onto the buyer to undertake their own inspection of the property/land.

If a buyer is concerned about the presence of Japanese Knotweed, then they should consider arranging for a specific survey from a suitably qualified surveyor or environmental consultant.

What should you do if you discover you have Japanese Knotweed in your garden?

Firstly, do not try to dig it up. Japanese Knotweed requires specialist waste management. You should contact the Invasive Non-Native Species Association or the Property Care Association (PCA) and they can advise you on local removal contractors. It is important to establish whether any professional you engage in the treatment and removal of Japanese Knotweed offers a suitable guarantee that can be relied upon by future purchasers and mortgage lenders.

There is currently no general duty to control, remove or report the presence of Japanese Knotweed however you may be committing an offence if you fail to take reasonable measures to control the Japanese Knotweed, and or are negligent or reckless resulting in the Japanese Knotweed spreading into the wild.

If you have any concerns or wish to discuss the matters raised further, then please contact our Commercial Property team on 01603 660 811 or email info@hatchbrenner.co.uk.

What does Japanese Knotweed Look Like

Japanese Knotweed

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