Japanese knotweed
The knotweed management plan covers only the front garden. What has it not told you?
It has not told you about the back, the side passage, or next door. A plan is as wide as the ground it says it inspected and treats. Silence on the rest of the plot is not a clearance. The home survey does not fill that gap by walking the lawn once, and it should not invent a management category for ground the plan never mentioned.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
RICS guidance on Japanese knotweed is about identifying impact and, where needed, specialist remediation. A management plan from a remediation firm should say where the plant was found and what will be done. If the drawing stops at the front boundary, the rear garden is outside that promise. Government guidance is that you must not cause knotweed to spread. A front-only plan does not licence tipping cuttings from a stand the surveyor noticed by the back fence, and it does not prove there is no stand there. Ask the firm, through the seller, whether the back was even inspected.
The surveyor’s own note might be “plan seen, relates to front garden only” or it might be a description of growth the plan does not mention. Keep those apart. Do not average them into one category. Do not start digging the untreated area to “check for roots”. Soil and plant material are how knotweed is spread, which is why government guidance is strict about disposal. If you need the whole plot covered, the specialist has to extend the plan, or you have to decide with your solicitor and your lender what an incomplete plan is worth. The home survey is not the missing half.
What should you ask your surveyor?
- Which parts of the plot does the plan actually cover?
- Did you see growth in any area the plan does not mention?
- Are you applying a management category to the whole garden? Please do not, if you only saw a front-garden plan.
What are the typical next steps?
- Send the lender the plan and say, in words, that it is the front only.
- Ask the seller whether the remediation firm inspected the rest of the plot.
- Do not dig out suspect growth or move the soil.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does a front plan mean the back is clear?
No. It means the back is not in that document. Clearance has to be written, not assumed.
Can the home surveyor extend the plan?
No. Extending a plan is the remediation firm’s work. The surveyor reports what they saw and what they were given.