Japanese knotweed and residential property

Published January 2022
Effective from March 2022
Reissued October 2022

This professional standard is an update to an RICS information paper published in 2012, responding to a House of Commons Science and Technology Committee published report – Japanese knotweed and the built environment – and a Department of Environment, Food and Rural Affairs (Defra) investigation into Japanese Knotweed that questioned the current approach to assessing the risk, and by extension, impact on value, of Japanese knotweed on the built environment.

The purpose of this updated document is to address both the findings and provide guidance based on market-informed industry best practice and the most recent research about a more holistic assessment of Japanese knotweed to ensure RICS members provide the best advice to users of valuation and condition reports.

This document contains a decision tree based on risk level to help valuers determine the appropriate management approach needed for Japanese knotweed. The new process still delivers a straightforward and objective categorisation of Japanese knotweed infestations because this provides the clarity that is essential for lenders, and which will continue to ensure confidence and trust among wider stakeholders.

This document was reissued in October 2022 as a professional standard. It had previously been published in February 2022 as a guidance note. The regulatory requirements remain the same and no material changes have been made to the document.