A Japanese knotweed survey and report is essential when selling or buying a property that is affected by Japanese knotweed.

A Japanese knotweed survey will provide formal identification of this non-native invasive plant species. It will also provide an accurate record of where the knotweed is located, the extent of the risk zones and remedial feasibility study.

Looking for a Japanese knotweed specialist? As we are a Property Care Association (PCA) member, we are approved by RICS (The Royal Institute of Chartered Surveyors) to undertake and complete these surveys.

Book a Japanese Knotweed Survey

To help understand and categorise the level of risk that the knotweed presents to the property, the Royal Institution of Chartered Surveyors (RICS) has created a “risk” table (see table below).

The level of risk is defined by the proximity of the knotweed to the habitable area or the property boundary and if any structural damage has been caused.

Japanese Knotweed risk categories

More information can be found on the RICS Japanese Knotweed and residential property guide.

Category Descriptors
4 Japanese Knotweed is within 7 metres of a habitable space, conservatory and/or garage, either within the boundaries of this property or in a neighbouring property or space; 


Japanese Knotweed is causing serious damage to outbuildings, associated structures, drains, paths, boundary walls and fences and so on. 

Further investigations by an appropriately qualified and/or experienced person are required.

3 Although Japanese Knotweed is present within the boundaries of the property, it is more than 7 metres from a habitable space, conservatory, and/or garage. If there is damage to outbuildings, associated structures, paths and boundary walls and fences, it is minor. 

Further investigations by an appropriately qualified and/or experienced person are required.

2 Japanese Knotweed was not seen within the boundaries of this property, but it was seen on a neighbouring property or land. Here, it was within 7 metres of the boundary, but more than 7 metres away from habitable spaces, conservatory and/or garage of the subject property.
1 Japanese Knotweed was not seen on this property, but it can be seen on a neighbouring property or land where it was more than 7 metres away from the boundary.


Do I have to declare Japanese knotweed?

The law around Japanese Knotweed changed in 2014. You should report certain non-native species on the Non-native Species Secretariat (NNSS) website.

Honesty is the best policy to avoid litigation and legal complications further down the road. You can read more on declaring Japanese knotweed here.

How much does a Japanese Knotweed Survey Costs?

At PBA Solutions we offer free Japanese knotweed surveys (Virtual) to homeowners. We then write a Knotweed Management Plan (KMP) that our clients can rely upon as an independent assessment of the Japanese knotweed problem. 

  • Within the KMP we would document:
  • Survey findings, 
  • Make proposals for treatment 
  • Provide a scale plan drawing to locate the knotweed 

The objective of the KMP is to clearly document the nature of the problem for mortgage lenders, prospective buyers and their solicitors. Naturally, our management plans have to be paid for since they are designed to become material documents within a property sale. We, therefore, urge people to be cautious of companies offering free management plans since these would not necessarily be suitable as a document of reliance. 

A lot of companies subsidise Knotweed Management Plans by making their customers pay a large one-off fee for the whole service including treatment and guarantee fees. At PBA our ethos is to offer a flexible approach where our clients only pay for what they need

Therefore a typical residential KMP is currently charged at £365.00+VAT. We off this either stand-alone or as part of a treatment package. We also make customers very aware of the fact they can start the treatment package with just a findings report which can then be upgraded during the treatment program to a KMP which is ideal for people who know they need a specialist to treat there knotweed but done need the expense of KMPS and guarantees when they don’t need to sell there house.    

For home buyers, we offer findings reports which start at £245.00+VAT. This is a simple survey and letter to confirm whether knotweed is present on site. At PBA Solutions we currently maintain £5m Professional Indemnity insurance which is considerably higher than the majority of our competitors giving our clients a greater degree of comfort.

For commercial surveys for Japanese knotweed, we would suggest that you should expect to pay in the region of £600.00 for a site appraisal and finding report for a typical site with one or two stands of knotweed. 

Japanese knotweed removal

When providing a KMP one of the most important elements of the report is the knotweed plan drawing. Such a plan must show the following:

  • The location of knotweed
  • The extent and shape of the land that is visibly impacted by knotweed
  • The extent and shape of the land which will be impacted by knotweed rhizome (roots) which is larger than the area that’s visibly impacted
  • The potentially impacted area of land often referred to as the 7m
  • The distance that the visible knotweed is from a dwelling, garage or similar building
  • The plan should be to scale or scalable
  • The extent of the subject property, ie the area that the report is referring to must be defined.
Japanese Knotweed sample site plan

Call us at the following regional offices:

London Office: 0203 1742187
South West – Head Office: 01202 816134
South East – Registered Office: 01730 893460
Midlands Office: 0247 651009

Operations office

PBA Solutions, Unit 2-3 Thorne Way, Woolsbridge Industrial Estate, Three Legged Cross, Dorset, BH21 6FB.
Tel: 01202 816134

London regional office

34 New House, 67-68 Hatton Garden, London, EC1N 8JY
Tel: 0203 174 2187

Registered address

Bryn Gardens, Liss Hampshire GU33 7HB
PBA Solutions is the trading name of PBA Solutions Landscape Ltd (3049561)


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