Article Loss Prevention

Japanese Knotweed – Professionals should know the law and their responsibilities

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Photo of Japanese knotweed invading a site recorded during a walkover survey.

Japanese knotweed is a non-native invasive bamboo-like plant that is very strong and grows incredibly quickly. It can cause damage to drains, paths, walls and foundations. Many mortgage lenders will not agree to lend against a property that is located within 7m of the plant.

In the County Court case of Waistell v Network Rail (2017), Network Rail was ordered to pay compensation to two home owners whose properties backed on to Network Rail land which was rife with Japanese knotweed. This case potentially opens the way for claims against owners of land containing Japanese knotweed and to property professionals advising them. The AGS have published Loss Prevention Alert No 67 which reminds Members of the law relating to Japanese knotweed, describes the Waistell case and the reasoning behind the Court’s decision, and discusses the responsibility Members have relating to Japanese knotweed when advising their clients on the purchase of land or on construction activities. AGS Members should also be aware of other invasive species such as giant hogweed which land owners could have a responsibility to control.

The case is significant as it holds landowners to account and imposes a positive duty on them to ensure that any knotweed that is on their property is not preventing neighbouring landowners from being able to sell their property for market value.

Damages can be claimed for costs of removing the Japanese knotweed or an order requiring the defendant to remove it, costs of any remedial works to the claimant’s property and diminution in value of the property.

The full Loss Prevention Alert 67 – Japanese Knotweed – Professionals should know the law and their responsibilities can be downloaded here.

Further information on Japanese knotweed and related issues can be found on the following websites.
Environment Agency (
Scottish Environment Protection Agency (
Royal Institution of Chartered Surveyors (
UK Government (
The Invasive Non-Native Specialists Association (

This article was contributed by David Hutchinson, Honorary Member of the AGS and featured in the March/April 2018 issue of the AGS Magazine, which can be viewed here.

Report Loss Prevention

Loss Prevention Working Group Report

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Hugh Mallett, Chairman LPWG writes:

The group is drafting articles and guidance on a number of issues that are important to AGS members, see below for the list of our ongoing work programme and soon to be available guidance.


The LPWG met once since the November Committee meeting – 22nd Jan 2015. No calls have been made to the Legal or Chemical Helplines since the last LPWG meeting.

A Griffiths & Armour publication on claims “Professional Indemnity Insurance: Lessons to be learnt” is to be made available to AGS members via the new website

LPWG generally agrees with putting some documents behind a paywall on the new AGS website. There is also support for a knowledge hub (e-learning) that could be considered as a future initiative for students.

Loss Prevention Alerts (LPAs) are still in high demand for downloading [20 LPAs downloaded >100 times between Oct and Jan].

New member has joined the  group, Nora Fung – Arup legal.

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Work in Progress

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Document on Ground Investigation Reporting (GIR/ GDR): Initial redraft prepared by J Strange – subject to further review/ comment. Now held to be consistent with revised BS5930.

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Limitation period and defects liability: Article being drafted

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