The short answer
A Japanese knotweed survey and report typically costs around £150–£350 in the UK. The price depends on the size of the site, access, and how detailed the report needs to be for a lender. That is the cost of assessing the problem — treatment is separate and far higher, with a herbicide programme usually £1,500–£3,000 and excavation running into many thousands.
Before committing to treatment, most people want to know what the survey itself will cost — and why a management plan costs more. This page sets out the typical survey price, the factors that move it up or down, and how to read a quote so you compare like with like.
Survey cost at a glance
- Survey & report £150–£350
- Drivers Site size, access, report detail
- Management plan Separate — part of the treatment quote
- Herbicide programme £1,500–£3,000 over ~3 seasons
- Excavation £5,000–£15,000+
The typical price
A standalone survey and written report for a residential property usually falls in the £150–£350 range. For that you should get an on-site inspection, confirmed identification, a mapped extent, a RICS risk category and a clear recommendation. Some specialists deduct the survey fee from the cost of treatment if you go on to instruct them.
What changes the cost
- Site size and complexity — a large garden or multiple boundaries takes longer to inspect.
- Access — growth on neighbouring land or behind structures can complicate the assessment.
- Report detail — a lender may want a fuller report than a homeowner who simply wants peace of mind.
- Location — travel and regional rates vary across the UK.
Survey cost vs management-plan cost
The survey tells you what you are dealing with; the management plan sets out and prices the cure. They are different line items. A plan is usually quoted as part of a treatment programme and reflects the method chosen.
| Item | Typical cost | What you get |
|---|---|---|
| Survey + report | £150–£350 | Assessment, risk category, recommendation |
| Herbicide programme | £1,500–£3,000 | Treatment over ~3 seasons, often with guarantee |
| Excavation | £5,000–£15,000+ | Physical removal, fastest result, highest cost |
Getting a fair quote
Ask whether the quote covers a written report with a RICS risk category, whether the surveyor is PCA-accredited, and whether the survey fee is credited against treatment. Compare quotes on what the report contains, not just the headline figure. For the wider picture of removal cost, see how much knotweed removal costs.
Get a survey quote
Arrange a PCA-accredited survey for a clear, fixed price — with a written report and RICS risk category your lender will accept.
Frequently asked questions
Why do survey prices vary so much?
Site size, access, location and the depth of report a lender requires all move the price within the typical £150–£350 band.
Is the survey fee refundable if I treat the knotweed?
Some specialists credit the survey fee against the cost of treatment if you instruct them — ask before booking.
Does the survey cost include treatment?
No. The survey assesses and recommends; treatment is quoted separately and costs considerably more.
Can I get a free knotweed survey?
Some contractors offer a free quotation visit, but a written report with a RICS category that satisfies a lender is normally a paid service.
Sources & further reading
- RICS — Japanese Knotweed and Residential Property guidance note (2022)
- Property Care Association (PCA) — invasive weed control standards
- GOV.UK — Prevent Japanese knotweed from spreading
This guide is general information, not a site-specific survey or legal advice. Japanese knotweed treatment and removal should be assessed by a PCA-accredited specialist before you act.