Japanese Knotweed: How Can It Affect the Sale of Your Property?

What Is Japanese Knotweed?

Japanese Knotweed (Reynoutria japonica) is a fast-growing, invasive perennial weed native to East Asia that can damage property foundations and outcompete native plants.

What Is the Problem?

Japanese Knotweed exploits any weak areas or gaps in structures such as concrete, walls and mortar. Underground, it can also cause damage to infrastructure such as sewers, drains, pipes and cables. As it grows, it expands these weak areas, causing damage.

Japanese Knotweed is a non-native invasive plant species. It has no natural predators here in the UK, is incredibly resilient, and can ‘re-grow’ even after you remove or treat visible growth.

How It Affects the Property

Whilst it is not illegal to have Japanese Knotweed growing on your property, it is an offence to plant it or cause it to spread into the wild. Additionally, allowing it to spread to a neighbour’s property can be classed as a private nuisance and can leave you open to a claim for damages.

If Japanese Knotweed is found to be growing on your land when you are trying to sell a property, it can reduce the selling price. If left untreated, it can also cause problems for lenders, whose main priority is ensuring that a property can easily be sold following repossession without a loss in value or problems that need to be resolved first.

How to Resolve Japanese Knotweed

Managing Japanese Knotweed can be very difficult because, during the winter months, the top part of the plant will start to die off, but the main root system underground remains alive and continues to cause damage to the surrounding area. If you have Japanese Knotweed on your property, it is important not to treat it yourself unless you have the relevant skills and experience. Professional intervention is the most appropriate solution, as it may take several years to fully eradicate the plant.

Please note that mortgage lenders will stipulate the following:

It must be inspected by a suitably qualified remediation specialist.
There must be no evidence of Japanese Knotweed on neighbouring land.
There must be a commitment to starting the recommended works.
There must be an insurance-backed Japanese Knotweed Management Plan in place.

A Japanese Knotweed Management Plan should include a multi-year timeline, typically comprising three years of treatment followed by a further two years of monitoring, and will contain an insurance-backed guarantee to protect against re-invasion.

If you are unsure about the presence of Japanese Knotweed when selling your property, it is important to consider hiring a professional surveyor to assess the property. This can help ensure accurate disclosure and avoid potential legal issues.

We are also happy to advise you on lending requirements and assist in obtaining the relevant documentation when you come to sell or purchase a property. Call us on 01329 822 333

Residential Conveyancing