Japanese Knotweed

26-04-2022

Valuations

3 min read

Japanese Knotweed is an invasive weed that spreads rapidly and can be difficult to control with professional support. The existence of the weed in or close to a property you want to purchase or sell may be a problem and you shouldn't ignore it.

Something that comes up in valuations is the issue of Japanese Knotweed. It is as the name suggests a weed. The issue with this particular weed is that it spreads rapidly and requires specialist help to get rid of it.

In spring it starts growing and fast, the thick stems, almost like bamboo can grow above 7ft tall. If not controlled it will get out of hand in just a few seasons. The longer it is left the wider it will spread and the harder it will become to eradicate.

You can cut them back and they will simply grow again, chemicals can be effective but it can take years to fully remove them as it is the roots underground that need to be targetted, not what is above ground.

It is not illegal to have Japanese Knotweed on your property but it could be illegal to let it grow beyond your boundary.

For small outbreaks, a property owner with the right plan could eradicate it in a few seasons. But I highly recommend looking at getting a specialist company in to deal with it properly and effectively.

What issues can Japanese Knotweed have on a property?

Japanese Knotweed not only grows tall but it also spread wide underground, often the roots can extend up to seven metres beyond what you can see above ground.

Japanese Knotweed Impact

If it gets into the foundation of the property it could cause structural damage. It can also cause problems if it finds a way into underground drains.

Both of these would be a concern to a lender and an insurer.

It doesn’t have to be on the property being purchased for the valuer or lender to be concerned.

A valuer may identify that Japanese Knotweed is in the area of the property being purchased, which is a concern given the roots can spread up to seven metres it may already be within the boundary of the property or have potentially reached the foundations.

This will be especially concerning if the Knotweed evidenced is not being controlled by a neighbouring property or more so if it is in land that is not being used and not under the control of a local authority that would need to deal with it.

Will a lender provides a mortgage?

The majority won't. The impact of Knotweed on the property being purchased due to the invasive nature of the weed makes lenders nervous of lending. Some may consider it if the current owner agrees to employ a specialist company to eradicate depending on the extent of the problem.

Some lenders will be a straight no, others may consider it with the pre-completion condition that will place actions on the current owner or some may lend with post-completion conditions that you address the problem without delay, but again it will depend on the extent of the issue.

You can find a heat map of the UK here. As you can see it is not isolated to any particular part of the country.

Lee Wisener, CeMAP, CeRER, CeFAP

Having worked in the mortgage industry for over 20 years I have always wanted to build a website dedicated to the subject. Also being a geek when it comes to the internet all I needed was time and I could both build the site from scratch and fill it with content. This is it!