We’re always warning people about the risks of selling a property without carrying out proper checks for Japanese knotweed, and our latest research with YouGov confirms why it’s a risky strategy.

Our survey of over 2,000 people found that almost two thirds (63%) would sue the seller if a property they bought was later discovered to have Japanese knotweed that had not been declared prior to the purchase.

Yet despite the risks, more than half (53%) of sellers would carry out insufficient checks, for example having a quick glance round the garden (21%) – or worryingly, doing nothing at all (14%).

A salutary tale

Recent cases have shown how failure to declare knotweed can result in sellers being sued for life-changing sums of money, even if the seller claims to have been unaware the knotweed was present. A homeowner in Raynes Park, London, who found Japanese knotweed behind the garden shed after he moved into his £700,000 property, successfully sued the seller for more than £200,000 in costs and damages.

The seller, who had answered “No’ to the knotweed question on the TA6 form, claimed in court that he wasn’t aware of the knotweed infestation and ‘reasonably believed’ he was telling the truth when he did so, but the judge determined that he had made a misrepresentation and was responsible for the diminution in the property’s value and legal fees.

Claiming ignorance

It might be tempting for sellers to simply state they don’t know if their property is affected by knotweed – and there is a ‘Not Known’ box on the form they can tick. But if a buyer’s legal team can prove they did know, for example if knotweed would have been clearly visible at that time of year, or a neighbour or gardener knew about it, or if they can prove some effort was made to treat or conceal it, there’s still a strong chance the buyer’s claim against them would be successful.

How to protect yourself

Knotweed now affects around 5% of UK homes, so crossing your fingers and hoping for the best really isn’t an option.

The only way to confidently state that a property is unaffected is to commission a professional Japanese knotweed survey, backed by a warranty. Our JustCheck™ survey is designed for buyers and sellers who want to make sure they’ve done everything possible to check for knotweed, with the documentation to prove it including a 5-year warranty which can be passed on if the property changes hands.

If you’re buying or selling a property, contact us today to find out more.