Japanese knotweed survey & management plan
A professional Japanese knotweed survey confirms whether a plant is knotweed, maps the infestation and its proximity to buildings, and produces a Knotweed Management Plan (KMP) — the document mortgage lenders, buyers and solicitors want to see. Surveys start from around £150, and a full KMP with an insurance-backed guarantee is what makes an affected property mortgageable.
What a knotweed survey involves
A qualified surveyor identifies the species, records the size and location of the stand, checks how close it is to structures and boundaries (the 7-metre and 3-metre benchmarks), and assesses the risk. You receive a written report and, where treatment is recommended, a Knotweed Management Plan setting out the method, schedule and guarantee.
Why you need a management plan
Lenders rarely lend on an affected property without a KMP backed by an insurance-backed guarantee. The plan reassures the valuer, transfers to the buyer on sale, and protects you from encroachment disputes. It's the single most important document for keeping a sale or remortgage on track.
RICS risk categories explained
Surveyors typically describe the risk using a simple A–D scale, driven mainly by how close the knotweed is to a building. It tells lenders and buyers how serious the situation is:
- ✓Category D: knotweed well away, low risk to the property
- ✓Category C: present but not currently threatening the building
- ✓Category B: within 7 metres, some risk — plan advisable
- ✓Category A: within 7 metres and affecting the property — plan required
Your management plan and insurance-backed guarantee are what move an affected property back to a lendable position, whatever the category.
What happens during a survey
A professional survey turns “is that knotweed?” into a documented, lender-ready plan. Here’s how the process runs from first call to finished report:
- 1Book the survey
You share the address and any photos. A PCA-accredited surveyor arranges a site visit, usually within a few days.
- 2Site inspection
The surveyor confirms the species, walks the boundary, and checks proximity to buildings, drains, walls and neighbouring land.
- 3Extent mapping & risk grading
The infestation is measured and mapped, then risk-graded (often using the RICS categories) based on how close it is to structures.
- 4Survey report issued
You receive a written report confirming the findings, photographs, the risk category and recommended treatment options.
- 5Knotweed Management Plan
If treatment is needed, the surveyor sets out a 5–10 year plan with method, schedule and costs — the document lenders and solicitors ask for.
- 6Insurance-backed guarantee
Once treatment is arranged, a transferable IBG underwrites the plan, protecting the property’s value and mortgageability.
For a sale or purchase, order the survey early. The report and management plan are exactly what a buyer’s solicitor and lender will request before proceeding.
