What are the challenges of buying or selling a property with Japanese Knotweed?


Buying or selling a property with Japanese Knotweed

When buying or selling a property, there are numerous factors to consider, from location and price to structural integrity and aesthetic appeal. One issue that can throw a significant wrench into the process is the presence of Japanese knotweed.

This invasive plant species is notorious for its rapid growth and ability to cause damage to buildings and infrastructure, leading to potential complications in property transactions. In this guide, we will explore what Japanese knotweed is, the challenges it presents, and how to effectively manage a property transaction involving this persistent plant.

What is Japanese Knotweed?

Japanese knotweed (Reynoutria japonica) is a highly invasive plant native to East Asia. Introduced to the West in the 19th century as an ornamental plant, it quickly spread due to its aggressive growth and resilience. Knotweed can grow up to 10cm per day and its root system can extend up to 3 meters horizontally and 3 meters deep, causing structural damage to buildings, roads, and flood defences.

The challenges of Japanese Knotweed in property transactions:

  • Structural Damage: The roots and stems can penetrate concrete, tarmac, block drains and limit access and enjoyment to amenity areas, leading to expensive repair and remediation costs.
  • Mortgage Issues: Many lenders are hesitant to approve mortgages for properties affected by Japanese knotweed due to the potential for future damage and the high cost of remediation unless there is a documented management plan put in place that is accredited by the PCA.
  • Property Value: The presence of knotweed can significantly reduce a property’s value, sometimes by up to 15%.
  • Legal Obligations: Sellers are legally obligated to disclose the presence of Japanese knotweed to potential buyers, and failure to do so can result in legal action.

Buying a property with Japanese Knotweed

  • Professional Survey: Before proceeding with a purchase, hire a qualified surveyor to assess the extent of the knotweed infestation. This will provide a clearer picture of the potential risks and costs involved.
  • Specialist Treatment Plans: Obtain a management plan from a professional knotweed removal company such as ourselves. Effective treatment plans can take 3-5 years and come with Insurance Backed Guarantees which reassure lenders and buyers.
  • Honesty and Disclosure: Be upfront about the presence of knotweed. Transparency will build trust with potential buyers and prevent legal issues down the line.

Given that the average property price across the UK is now approaching over £280k, a Japanese Knotweed survey should be viewed as a crucial step in the house buying process. 

By having a survey completed this can help identify issues before they become a legal headache, and it is important to not underestimate the importance of having a Japanese Knotweed survey completed prior to completion.


For expert Japanese Knotweed Removal, to book a free survey or just to have a quick chat – you can call us on 0800 2884967 or email info@inspectas.co.uk.

For any invasive weed & Japanese Knotweed questions …

… call us FREE on 0800 288 4967 or email info@inspectaslr.co.uk

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