Pre-purchase Japanese knotweed risk report
Contents |
[edit] Introduction
Japanese knotweed, a plant species that is not indigenous to the UK, is highly invasive and often causes extensive damage to property and to natural ecosystems. As a result, property values and lending decisions are often affected by its presence even if it is just in the near vicinity.
Non-native, invasive plant species are now regarded as one of the biggest threats to biodiversity worldwide, with the Centre for Environmental Studies estimating that £1.6 Billion is spent annually in the UK to remove Japanese knotweed.
[edit] What damage does Japanese Knotweed cause?
Growing up to 10cm a day, Japanese knotweed often targets the weakest points of building structures and substructures, such as cracks. Common damage from Japanese Knotweed includes:
- Damage to building foundations.
- Damage to housing drainage and underground sewers.
- Damage to tarmac and concrete areas.
- Damage to retraining walls.
[edit] Pre-purchase report
It is essential that property professionals are aware of the presence of Japanese knotweed on a site, or in the vicinity, and have the ability to make an informed decision on the risks.
A report has been developed that utilises a due diligence system search that will allow clients to understand these risks ahead of any purchase.
The report utilises innovative remote sensing technology to highlight Japanese knotweed adjacent to, or on, commercial property sites. This allows commercial conveyancers, developers and surveyors to identify potential management costs as well as lending risks before purchasing properties.
A pre-purchase Japanese knotweed risk report might include:
- A location map.
- Indicative buffers showing the potential coverage of root systems.
- Unique remote sensing technique returns data.
- A site boundary polygon with 250m radius buffer.
- Polygon areas for knotweed stands greater than 5m2.
Additional expert advice may then be necessary:
- Follow up plant verification service.
- Guidance about Japanese knotweed treatment options, tailored to available time scales and budgets.
This article was created by --.MAPbyGroundsure
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
The Home Energy Model and its wrappers
From SAP to HEM, EPC for MEES and FHS assessment wrappers.
Future Homes Standard Essentials launched
Future Homes Hub launches new campaign to help the homebuilding sector prepare for the implementation of new building standards.
Building Safety recap February, 2026
Our regular run-down of key building safety related events of the month.
Planning reform: draft NPPF and industry responses.
Last chance to comment on proposed changes to the NPPF.
A Regency palace of colour and sensation. Book review.
Delayed, derailed and devalued
How the UK’s planning crisis is undermining British manufacturing.
How much does it cost to build a house?
A brief run down of key considerations from a London based practice.
The need for a National construction careers campaign
Highlighted by CIOB to cut unemployment, reduce skills gap and deliver on housing and infrastructure ambitions.
AI-Driven automation; reducing time, enhancing compliance
Sustainability; not just compliance but rethinking design, material selection, and the supply chains to support them.
Climate Resilience and Adaptation In the Built Environment
New CIOB Technical Information Sheet by Colin Booth, Professor of Smart and Sustainable Infrastructure.
Turning Enquiries into Profitable Construction Projects
Founder of Develop Coaching and author of Building Your Future; Greg Wilkes shares his insights.
IHBC Signpost: Poetry from concrete
Scotland’s fascinating historic concrete and brutalist architecture with the Engine Shed.
Demonstrating that apprenticeships work for business, people and Scotland’s economy.
Scottish parents prioritise construction and apprenticeships
CIOB data released for Scottish Apprenticeship Week shows construction as top potential career path.
From a Green to a White Paper and the proposal of a General Safety Requirement for construction products.
Creativity, conservation and craft at Barley Studio. Book review.
The challenge as PFI agreements come to an end
How construction deals with inherited assets built under long-term contracts.
Skills plan for engineering and building services
Comprehensive industry report highlights persistent skills challenges across the sector.
Choosing the right design team for a D&B Contract
An architect explains the nature and needs of working within this common procurement route.
Statement from the Interim Chief Construction Advisor
Thouria Istephan; Architect and inquiry panel member outlines ongoing work, priorities and next steps.

























