There’s a reason why the words “Japanese knotweed” often strikes fear in the hearts of homeowners and potential property buyers nationwide. Japanese knotweed can have a substantial impact on house value, leaving your finances in a bind of their own.

In extreme cases, an invasion of the Asian vegetation can slash a property’s price tag by as much as half, while a decrease in value by tens of thousands is far from unusual. Simply put, Japanese knotweed can be a monumental pain in the grass, leaving both your home and your finances in a precarious position.

japanese knotweed

What does Japanese knotweed do to a house?

Okay, first things first, you’re probably wondering “What damage can Japanese knotweed do to my home? After all, it’s just a plant, right… RIGHT?!”

Wrong. In fact, this botanical beast from the east can rock your house to the core. The visible plant can grow up to over two metres in height, while its roots can grow as much as three metres deep and stretch out up to seven metres wide from the surface growth.

The roots themselves are bamboo-like and can spread thick and fast. If left untreated, they can quickly block drains, weaken walls and even damage the foundations of your property, with the potential to seriously affect the value of your property.


Japanese knotweed and mortgages

Due to the structural dangers associated with the hellish herb, it can be difficult for would-be homeowners to find a mortgage for properties with Japanese knotweed. That being said, it isn’t impossible…

Most lenders will require a professional surveyor to assess the property, in order to evaluate the risk and/or damage. If the knotweed is causing severe problems or poses a substantial risk, it can have a direct effect on your mortgage application.

While all lenders will have their own individual checks and preferences, there are a few factors that typically come into play.

Japanese knotweed on neighbour’s property

If your neighbours have Japanese knotweed in their garden, mortgage lenders will then need to determine if your home is at risk of it spreading.

If the knotweed is more than seven metres away from the property boundary, this is typically deemed low-risk; however, if the weed is discovered within seven metres of the property boundary, this can be viewed as a concern for some lenders.

Japanese knotweed on your property

Similarly, even if the knotweed is present on your own land, the distance of it from the habitable part of your property can also be a big factor.

For example, if Japanese knotweed is discovered in your garden but it’s more than seven metres away from your house, you may still be granted a mortgage (although a specialist survey is likely before approval).

If the knotweed is discovered within seven metres of the living space, it likely poses a substantial risk and could well have already damaged the property, surrounding drains or its outbuildings. Repair work will likely be needed before approval.


If your property is at risk from Japanese knotweed, don’t let it tie your finances up in knots. Call Taylor Weed Control today on 029 2039 7554 or fill out our online enquiry form below and nip it in the bud now – it could save you a bundle! 

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