Japanese knotweed – horror or hype?

Over the past few years there has been a flurry of excitement about the effects Japanese knotweed can have on a property – and on a property transaction. But are the effects of Japanese knotweed exaggerated? Our property team at Bennett Griffin explains more…

What is Japanese knotweed?

Japanese knotweed is a hugely invasive species of plant that, if left untreated, can cause damage to your property including its drains, walls, drives, pathways etc. It was introduced to Great Britain in the 19th century and can lie dormant for a number of years. It can spread very rapidly (up to 10cm per day between April and October) and its roots can extend deep into the ground and up to seven metres laterally. The costs of eradicating Japanese knotweed and treating the site are substantial. It has been estimated that over 1 percent of properties in Great Britain are infected or have been so in the past.

Japanese knotweed in property transactions

It therefore comes as no surprise that many potential buyers and lenders will be deterred from proceeding with a property transaction once it becomes apparent that Japanese knotweed has been located on the site. Japanese knotweed is a problem because it can cause damage to the building, which will affect the value of the property and possibly the likelihood of being able to sell the property in the future. Getting rid of the plant will be time consuming and expensive and it may be difficult to get insurance for the property. Mortgage lenders may decline to lend, limiting the marketability of the property.

So, in practice, how does Japanese knotweed affect a property transaction? The Law Society have updated their Property Information Form (Law Society Transaction Form TA6 (Third edition)) to include a specific enquiry. The enquiry asks the seller if there is knotweed on the property and if so, asks them to state whether there is a Japanese knotweed management plan in place. Sellers who do not disclose its presence when completing the form risk a claim for misrepresentation by the buyers. As any prudent lawyer would, we clarify our client’s response by stating that any reply given by the seller in this respect should be verified by the buyer since the seller is not an expert on horticultural matters. Let’s face it, how many of us would be able to recognise this plant if it grew in our back garden?

Any buyer should be advised that regardless of the seller’s response, they should ask their own surveyor to check the property carefully for any signs of Japanese knotweed. Please note that the form does not ask if the seller is aware of the presence of Japanese knotweed at a neighbouring property. Bearing in mind the ease with which it can spread through its underground root-like stem fragments this is certainly worth noting.

What your lender would say….

The Council of Mortgage Lenders (CML) has indicated that Japanese knotweed can cause some problems in the residential housing market http://www.mindanews.com/buy-inderal/ because of the concerns about the damaging effects of the plant. The first time a lender will hear of Japanese knotweed at the property will usually be when their valuer mentions this in their valuation report.

Each lender has a different policy when it comes to properties affected. Therefore, it does not automatically mean that a buyer is unable to obtain a mortgage for the property but instead, individual lenders will treat such cases differently. Some lenders will take into account a range of factors when considering whether to lend on the property, considering applications on a case-by-case basis so the more information we can give to the lender the better.

Generally, where works are carried out for the removal of the plant, lenders will look for evidence of some initial treatment together with a commitment for ongoing treatment in the future. Any remediation works should normally come with an insurance backed guarantee to ensure that should the problem reoccur, any further remediation works are covered. It is worthwhile to note that where Japanese knotweed has been identified at a neighbouring property, some lenders have been hesitant to lend and therefore buyers and surveyors should ensure they bear that in mind when carrying out their investigations.

What the law says….

It is not a criminal offence to have Japanese knotweed on your property and there is no obligation to control, remove, eradicate or treat Japanese knotweed at your property. However, it is a criminal offence to plant it or to cause it to grow in the wild. This would include failing to take reasonable measures to control knotweed that results in the plant spreading to the wild, or being negligent or reckless about that happening (Section 14(1) and (2) of the Wildlife and Countryside Act 1981).

In addition, the Local Authority or the police have the power to serve a community protection notice under the Anti-Social Behaviour, Crime and Policing Act 2014 or (in the case of the Local Authority) serve a notice on an occupier requiring it to remedy the condition of the land within a specific period where the amenity of an area (or adjoining area) is adversely affected (section 215 Town and Country Planning Act 1990).

What if a property has previously been treated?

Where Japanese knotweed is treated or removed, then we should insist on seeing a copy of the guarantee for these works. We would ensure this guarantee can be assigned to our clients and any subsequent owner or occupier of the property. The guarantee may be backed by insurance which means our clients are covered even if the company who carried out the works has gone out of business.
Article written by Adriana Campbell, solicitor in the Property team. For more information  or assistance contact Adriana on 01903 706954.







The information contained in this article is for general guidance only and is not intended to be legal advice. Professional advice should always be taken on the application of the law in any particular situation