Japanese knotweed
What is RICS management category A for Japanese knotweed?
Category A is “Action”. The 2022 RICS property journal describes it as knotweed on the property causing visible material damage to a significant structure. The same article says that in all cases the client should be advised to consult a remediation specialist, and that lenders were expected to look for a specialist report where the category is A or B.
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?
The journal of 21 March 2022 is explaining the professional standard that took effect on 23 March 2022. It replaced a blunt distance test with a judgement about impact. Category A is the serious on-site case because the plant and the structure are both involved. It is not a phrase a neighbour’s photograph can settle. The surveyor has to have seen the damage and the plant, or say they have not.
Do not turn “expected to impose retentions” in a 2022 article into a promise about your lender in 2026. Ask this lender what they want. Ask a remediation firm, not a general gardener, for a management plan if the surveyor has used category A or described that kind of damage. Government guidance still says knotweed must not be allowed to spread. The plan is how a specialist proposes to deal with it. Prices vary. Ask the firm.
What should you ask your surveyor?
- Did you see visible damage to a structure, or only growth in the garden?
- Are you applying the 2022 management categories, or describing the plant without a category?
- What specialist advice do you expect me to get before exchange?
What are the typical next steps?
- Send the lender the surveyor’s wording, including the category if one is printed.
- Instruct a remediation specialist who will write a plan. Do not strim the plant.
- Ask the solicitor what the seller must disclose, and whether a plan already exists.
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
Is category A the same as the old seven-metre rule?
No. The journal says the old distance test was replaced. Category A is about damage on the property, not a tape measure from a boundary.
Does category A mean you must walk away?
No. It means the impact is serious and a specialist’s advice is part of the decision. Walking away is your choice once you have that advice and the lender’s position.