Japanese Knotweed Legislation

Once the identification process has been completed, the contamination must be controlled according to the law. The destructive impact knotweed has in certain areas has become a major problem. As a result, Japanese Knotweed legislation has been put in place to try and bring some control. This is a list of the various relevant Japanese Knotweed UK law and acts which dictate the correct treatment process.

Is it illegal to have knotweed on your land or property?

It is not illegal to have Japanese Knotweed on your land. However, Japanese Knotweed legislation dictates that you must take reasonable action/steps to prevent it spreading to your neighbour’s land. If it does spread, your neighbour may be able to sue you in the civil courts. This Japanese Knotweed legislation guide will be able to help you determine who is responsible for clearing Japanese Knotweed. Ultimately, responsibility to control rests with the owner of the land. However, local authorities do not have to control it on behalf of other landowners. In most cases, actions in civil courts can be expensive and risky. Therefore, it is best to consult with the owner and point out their obligations first.

Countryside & Wildlife Act 1981


The Countryside & Wildlife Act Japanese Knotweed legislation applies if any person plants, or otherwise causes the growth of wild any plant which is included in part 2 of schedule 9, they shall be found guilty of offence. Japanese Knotweed is included in the schedule of plants. Any person convicted under this act could be liable to a fine of £5,000 and/or 6 months in prison, or 2 years in prison and unlimited fines on indictment.

The Environment Protection Act 1990

This Environment Protection Act piece of Japanese knotweed legislation refers to controlled waste. If you intend to remove the weed, including the infected soil, from any site, it is classified as controlled waste. If you do not have the correct licenses and vehicles, in accordance with the regulations contained within this act, you can be prosecuted and are liable for a substantial fine.

Hazardous Waste Regulations 2005

The Hazardous Waste Regulations leglisation is only applicable if Japanese Knotweed has been treated with certain residual herbicides. Again, failure to comply with this act could lead to prosecution.

digging spade

Waste Management Licensing Regulations 1994

This law primarily relates to the failure to use a licensed operator, proper methods and materials that may endanger the safe recovery and disposal of waste. In particular, without endangering human health, harming the environment or causing nuisance.

Town & Country Planning Act

The attitude and interpretation of this act varies from local authority and the appetite to take action again may vary. For instance, landowners with Japanese knotweed present on their land can be forced to clear up. Especially if it is deemed to “adversely affects the amenity” of the neighbourhood.

Tax Relief for Japanese Knotweed (LRTR)

Companies that take action may be able to offset the cost of treating and controlling knotweed. Rates of relief vary according to circumstances. For example, you can receive 50% relief on expenses incurred treating and controlling the Japanese weed.

Buying a House with Japanese Knotweed


If you are buying a house with Japanese knotweed within its boundaries, or on land adjacent to your property, some lenders may require a comprehensive survey (JKMP) to support any application for a mortgage. These rules also apply to selling a house with Japanese Knotweed and forms an integral part of legislation.

Japanese Knotweed Management Plan (JKMP)

Part of the weed survey includes a detailed plan of how to manage the spread of the invasive plant. Consequently, this can then be used to support a mortgage application when purchasing a property. Additionally, it may be required as part of a planning application, as required by legislation. The list below covers the main features of the survey.

  • Produce a site plan with photographs.
  • Confirm and describe the level of contamination on and off the site.
  • The size, location and number of stands, proximity to water, map distances to buildings.
  • Carry out visual surveys of the adjacent sites to identify potential encroachment.
  • Advise of the risk of not taking the necessary action to control the plants.
  • We will recommend the most suitable treatment option and program specifying what materials, or herbicides, to be used.
  • When, by what method and the cost in accordance with the code of conduct recommended by the Environment Agency & Natural Resource Wales.

It is important to establish what type of report and insurance backed guarantee is required by the lender. There may be a cost involved carrying out a survey and producing comprehensive Japanese knotweed Management Plan.

The Royal Institute of Chartered Surveyors (RICS)


The Royal Institute of Chartered Surveyors (RICS) has produced an information paper entitled Japanese Knotweed and Residential Property.

The RICS has tried to clarify the responsibility that lenders have towards properties with Japanese knotweed. Many residential mortgage lenders are not keen to lend on properties affected with knotweed. However, they may consider applications providing the purchaser, or seller can prove there is a commitment to adequately fund an appropriate treatment program. Consequently, the production of a Japanese knotweed management plan based on a survey can establish the level of risk as specified by the RICS table below.

Lowest risk

CATEGORY 1 – Japanese knotweed was not seen on the property surveyed, but it can be seen on a neighbouring property or land where it was more than 7 meters away from the boundary.

CATEGORY 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 meters of the boundary, but more than 7 metres away from the habitable spaces, conservatory or garages of the subject property.

CATEGORY 3 – Although Japanese knotweed is present within the boundaries of the property, it is more than 7 metres from a habitable space, conservatory and garage. If there is damage to out buildings, associated structures, paths and boundary walls and fences it is minor.

Highest risk

CATEGORY 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; and or Japanese Knotweed is causing serious damage to outbuildings, associated structures, drains, paths, boundary walls and fences etc. Whatever the level of contamination we have a successful track record controlling Japanese Knotweed in a variety of situations

Guarantees and Transfers to New Owners

Guarantees have to be confirmed at the start of the program. We can supply 5 or 10 year guarantees and if required insurance backed guarantees (IBG). A third party insurer underwrites the guarantee we place on our work.
What happens when I sell my property? – Transferring programs and guarantees.

The Japanese Knotweed Survey & Management -Treatment Plan, the treatment program & relevant guarantee can be transferred to the purchaser/ new owner.

Encroachment and the Law

The presence of Japanese Knotweed on adjacent property or land has the potential for contamination across the boundary line. If Japanese Knotweed spreads from one property to another the relevant law is of private nuisance which is “an act or omission which is an interference with, disturbance of or annoyance to a person in the exercise of the enjoyment of his ownership or occupation of land.”

If your property is affected by knotweed because of encroachment the landowner of the adjacent property could be held responsible. It is not illegal to have knotweed on your land it is illegal to allow it to spread.

All landowners, even Councils, Network Rail and farmers have a legal obligation to control the spread of Japanese Knotweed from their land to adjacent properties.

Insurance Backed Guarantee

Some banks and lenders will ask for an insurance backed guarantee. IBG provided from an independent third party Insurance Company. The insurance backed guarantee will provide you with an extra level of protection. This even includes in the unlikely event we should cease to trade.

If a defect covered by the original guarantee develops an insurance policy, we will pay for another qualified contractor to remedy the works in line with the guarantee. A guarantee certificate can only be supplied if the whole program has been paid for in advance. The cost of the insurance premium plus a small charge for admin has to be added. It is usually around £180 per policy. If the insurance company will not accept and insure the treatment program on the property, then any premium paid will be refunded.

  • 3 year treatment program plus 2 year monitoring plus a 5 year IBG will cost £1,645 plus VAT, the premium and an admin fee of £180.
    3 year Treatment program plus 2 year monitoring program plus a 10 years IBG will cost £1,945 plus VAT, the cost of the premium and admin fee of £180. Prices subject to change.
  • Includes specialist knotweed surveying policy fee and insurance premium tax (IPT)
  • Initial chemical treatment to the affected area(s) within your property as outlined in the program.
  • Chemical treatment of any regrowth or recurrence of Japanese knotweed at no additional cost.
  • Continued periodic site inspections throughout the IBG period.