The Royal Institute of Charted Surveyors (RICS) recently closed its consultation on Japanese knotweed on 3 August 2021. The new guidance will replace the previous information paper issued in 2012. The aim of the updated guidance is to minimise the stigma surrounding the presence of Japanese knotweed and its effect on the conveyancing process. Stella Seimeni, B P Collins says that although the advice indicates that it’s not damaging as previously thought, it is still vital to obtain as much information from a houseseller early in the transaction and ensure that adequate insurance is put in place.

Historically, the presence of Japanese knotweed has been a cause for concern for residential property owners and lenders. The plant was known to cause delays in the transaction process and even reduce the value of a property. The possibility of a civil claim in nuisance following encroachment of Japanese knotweed to an adjoining property, scared off potential buyers. Mortgage providers also require to be informed of its presence as well as any treatment plan put in place.

RICS guidance on Japanese knotweed

The updated RICS guidance, which is based on new research carried out on the subject, explains that the effect of the plant is not as damaging as previously thought. According to RICS, Japanese knotweed is unlikely to damage structurally sound buildings, but it can cause damage to lighter structures like walls and drains. In addition, the distance that Japanese knotweed is indicated to cause damage to a structure has been reduced from seven to three metres. 

The guidance also focuses on promoting effective management methods as a viable option when complete eradication is not feasible. In many cases, the recommended treatment plan is applying herbicides instead of removing the contaminated soil. Japanese knotweed should be viewed as a treatable environmental risk assessed through an objective system of risk classification. As Philip Santo, the author of the new guidance, stated “knotweed isn’t a death sentence for home sales … in most instances, the weed can be remediated with effective treatment”. 

How does this affect you when buying a house?

It is estimated that 1.45 million UK homes are affected by Japanese knotweed. The new guidance is therefore a welcome update which provides clarity and tackles the misinformation surrounding the plant. 

Nonetheless, despite the recent developments, the presence of Japanese knotweed on a property can still cause disruption to the conveyancing process. It is crucial to obtain as much information from the seller early in the transaction and ensure that adequate insurance is put in place. 

The updated guidance is currently in draft form and we await for the final document to be published later this year. 

For further information or advice on this article, contact our criminal team on or call 01753889995.

If you’d like to receive complimentary advice articles from B P Collins straight to your inbox, please sign up here.

Related Services

Related Team Specialists

Speak to an expert

Or send us an email