Japanese knotweed and the built environment


Terms of reference


1 Introduction

What is Japanese knotweed?

Our inquiry

This Report

2 Scientific evidence of the physical effects of Japanese knotweed

The latest peer-reviewed research

Capacity for regrowth and difficulties in management

Other sources of information

Knotweed remediation firms

Expert testimony


3 Non-physical effects of Japanese knotweed

Fear and reputation

Treatment costs

Loss of amenity

Stigma and the requirement to declare when selling property

Liability for spread to other properties

Comparisons with approaches taken in other countries


4 Information and guidance to support lending decisions

Lending decisions prior to 2012

The 2012 RICS risk framework

Current lender attitudes

The origins and evidence for the ‘seven-metre rule’

Calls to update the RICS framework to reflect the latest research

Calls for a more nuanced approach


5 Helping homeowners

Additional legislation?

Neighbour disputes

Private nuisance

Disputes involving Network Rail

Conclusions and recommendations

Formal minutes


Published written evidence

List of Reports from the Committee during the current Parliament

Published: 16 May 2019