Japanese Knotweed

Although not harmful to humans, Japanese knotweed (Fallopia japonica) is a real thug.  Homeowners and buyers need to be aware of this perennial weed, what it looks like, and how to deal with it.

Why is Japanese knotweed bad for houses?

Japanese knotweed is an invasive species of plant which if left untreated can cause physical damage to a property.  It can be successfully treated and eradicated, although the Royal Horticultural Society advise that treatment and eradication requires determination.  It is certainly not simply a question of digging it up.  Eradication will require specialist long term chemical treatment and the correct disposal of any plant material.

Does Japanese Knotweed affect mortgages?

Mortgage lenders are aware of Japanese knotweed and its significance and their valuers are instructed to check for its presence.

Getting a mortgage for a property with knotweed is not straightforward and the attitude of different mortgage lenders varies.  Some will not lend on a property with Knotweed.

Those that are prepared to lend will almost certainly require a professional management plan to be in place.

What do I do if I am selling my house and it has Japanese knotweed?

There is a standard enquiry to be answered by everyone who sells a property as to whether they are aware of the presence of Japanese Knotweed on their property.

If it is discovered during the course of the sale then a plan will need to be put in place for its eradication, a decision made as to who is to pay for it (either the seller or the buyer), and approval of the plan obtained from the buyer’s mortgage lender.  Most mortgage lenders will not lend on a property without an eradication plan in place.  It is also likely to be a requirement that a treatment plan offers an insurance backed guarantee.

What you need to know if you are buying a house with Japanese knotweed

Japanese knotweed can cause structural damage to a property and spreads quickly between houses.  If you buy a property with it you will be taking on the responsibility for controlling it and stopping it spreading.

Knotweed can devalue a house depending on the severity of the infestation and its distance from the house.

Surveyors might not always check for the presence of knotweed and you should ensure that you specifically raise this point with a surveyor.

You can still obtain insurance for a property with Japanese knotweed but the insurance will not cover the removal or eradication of the Japanese knotweed.

Here to Help

For advice on this or other Residential Property issues, please contact Chris Pease, Joint Senior Partner and Head of Residential Conveyancing.

Please note the contents of this article are given for information only and must not be relied upon. Legal advice should always be sought in relation to specific circumstances.