The Law Society TA6 form is used in most domestic conveyancing transactions in England and Wales and recent versions up to and including the latest version (5th Edition, 2024), the form has made reference to Japanese knotweed. The question “Is the property affected by Japanese knotweed?” has the possible answers ‘Yes’, ‘No’ and ‘Not known’.
The explanatory notes for the form state that “If you choose ‘No’ as an answer, you must be certain that, even if you cannot see any growth above ground, no rhizome (root) is present in the ground of the property or within three metres of the property boundary… If you are not sure, indicate this as ‘Not known’.”
For many of our contractor members – dedicated Knotweed specialists – it seems that answering ‘No’ is too great a risk. Most specialist’s reports, where no Knotweed is found, would include a statement to the effect that “no knotweed was observed in the survey” – which is very different to declaring that there is no knotweed on site.
Japanese knotweed can re-grow from tiny fragments – a piece as small as a fingernail, or weighing as little as one gram can re-grow. This means that if a surveyor misses a tiny fragment of underground knotweed on their survey, that declaring the site to be free from Knotweed would be inaccurate and leave them open to claims of professional misrepresentation or negligence and potentially to claims on their professional indemnity insurance.
So while it may seem that the surveyor is abdicating any responsibility for the accuracy of the survey, it is very hard to verify even with extensive and invasive underground investigation that a site is actually free of Japanese knotweed. Even in cases where members have been called upon to investigate whether stockpiles of material are contaminated with Japanese knotweed, machine- or hand-screening and full visual inspection of a stockpile would most likely only result in a declaration that the soils are 99% free from Japanese knotweed or similar.
The jeopardy for someone selling a domestic property is similar and has been observed in court cases involving buyers suing sellers after Japanese knotweed was discovered once the sale has been completed and in some cases involved accusations of misrepresentation – court cases in which awards for costs have been in the hundreds of thousands of pounds.
It is often suggested that by answering “Not known”, the seller shifts the responsibility onto the buyer – but there is no clear guidance to inform a vendor at what point they are expected to state ‘Yes’ instead of ‘Not known’. Where a Knotweed treatment programme is complete and the site has been free of regrowth for two full growing seasons, a specialist can issue a completion certificate and potentially provide a guarantee (whether insurance-backed or otherwise). You would think that logically the homeowner should be choosing between telling their buyer that “no” there is no Knotweed or stating that it is “not known” whether the plant might still be alive in some form. However, in common language, it is also clear that the property “has been affected” by Japanese knotweed, and not unlikely that there is some “effect” remaining – including areas where vegetation has not fully regrown…
So, in that case, should the homeowner actually answer “Yes”, even after spending significant amounts to remediate the problem, in line with industry best practice and mortgage lenders’ usual standard for lending?
The only reliable answer would come from a competent conveyancing solicitor. By providing accurate and reliable information, a homeowner may be able to protect themselves in the same way that a specialist’s report protects them – by providing information to the best of their knowledge and belief, but without making declarations that could be subject to misinterpretation or turn out to be false.
INNSA can’t provide advice on conveyancing, and our contractor members are unlikely to provide this advice either – but we can provide information for anyone buying a house, or anyone looking to find out whether a property is affected by invasive species (there are many problem plants which could affect your enjoyment or the material of a property).
INNSA members are also able to provide Knotweed management plans covered by insurance-backed guarantees, which are likely to satisfy the requirements of a mortgage lender for providing funding on a property affected by Japanese knotweed – contact a member today if you have any queries or to book a survey.