Property or Development Land with Japanese Knotweed

Property or Development Land with Japanese Knotweed

Japanese knotweed on your land, property or development land can cause a huge amount of time and money to resolve and you should always use the services of a qualified NCPT Japanese Knotweed specialist. Our Property or Land with Japanese Knotweed article tells you everything you need to know if you are in this situation.

Japanese Knotweed causes financial difficulties for developers from the planning stages, the delays to construction and the cost of removal so knowing and understanding what you should do if you’ve never been in this situation before can ensure your building work starts as quickly as possible.

Japanese Knotweed is one of the UK’s most invasive plants and is also sometimes be referred to as Fallopia Japonica, Bamboo or Peashooters. It is a perennial weed which grows and spreads quickly from one tiny fragment of crown or rhizome (its root) if it isn’t controlled. The crown and rhizomes root system will suppress other plants growing around it and will spread quickly and extensively underground. Well-established shoots can grow more than 3 metres high above the ground and it can colonize the soil within a year. In the height of its predominant growing season, 60% of its roots are underground making its removal very difficult if you don’t have the specialist skills, knowledge and equipment.

How long does it take to remove Japanese Knotweed?

It depends on how widespread the knotweed is as to how long it will take to remove. A large infested area can take anything up to 5 years to completely remove and this is done by using specialist chemical treatments which should only be used by a Japanese Knotweed specialist. Japanese Knotweed can be completely removed through an excavation process and this is the quickest removal method. The knotweed and its roots are dug out of the ground and safely removed and transported to a regulated site to prevent the risk of it spreading. The disposal of knotweed is classed as “controlled waste” under the Environmental Protection Act 1990 and it has to be disposed of at a licensed landfill site which can be logistically difficult as well as costly. The risk of disturbing the roots are during removal are high due it spreading from just one tiny fragment and the evacuation method is normally only used for development sites where construction work needs to start quickly.

How do you remove Knotweed?

Japanese Knotweed is almost impossible to control and remove yourself if you don’t have the experience and relevant qualifications in the removal and control of knotweed. A qualified NPTC business will have the experience and knowledge to use the right chemicals and can advise you on the most efficient and effective way of removing it. Disposal of knotweed is classed as “controlled waste” under the Environmental Protection Act 1990, and this means it has to be disposed of and by a registered waste carrier at a licensed landfill site which a Knotweed Specialist will have the qualifications to do. It is illegal to dispose of Japanese knotweed along with other soil.

What should you do if you find Knotweed?

If you find or think you have Japanese knotweed at your property of development site it is your responsibility to control it, however, you are not legally required to remove it. Removing or disposing of Japanese Knotweed without experience and knowledge will result in it spreading and this is the illegal part, therefore, making it vital to have it dealt with by a Knotweed NPCT qualified specialist who can advise you on the most effective way to control or remove it.

City & Guilds NPTC, now City & Guilds Land Based Services is the UK’s largest awarding body in the land-based sector. It encompasses agriculture, horticulture, forestry, animal care, conservation, machinery and more.

There is no legal obligation to remove or treat knotweed as long as you are not encouraging or allowing it to grow onto any adjacent land (schedule 9 of the ‘Wildlife and Countryside Act 1981’ states, you must not plant or cause to grow Japanese Knotweed in the wild).

If Japanese Knotweed is allowed to spread onto your land then you can issue private nuisance proceedings in the Civil Courts for:

  • damages for loss of enjoyment and diminution of value of a property
  • the costs of removal
  • an injunction against re-infestation

Local Authorities have the power to serve notice on an occupier of land which has Japanese Knotweed growing. The notice can require them to control or remove any knotweed which could adversely affect the amenity of an area within a set period, and failure to do this, or failure to safely and properly dispose of the knotweed can lead to criminal liabilities.

Land with Japanese KnotweedCan new development sites build on land with Japanese knotweed?

If there is Japanese Knotweed present on development land then it has to be declared and accounted for in the planning process of the construction in order to legally start development. When selling your home you complete a TA6 form which is a general questionnaire for property sellers which includes declaring if you have Japanese knotweed on your property or if you are aware of it being present on neighbouring properties making sure the buyers are fully aware. The TA6 forms part of the pre-contract documents and this makes it’s content legally binding. However, it’s shocking to know that new-build developers are not required to fill in a TA6 Property Information Form and this enables them to sell a property affected by knotweed without them declaring it and them making the buyer aware of it.

When buying a new build property the only way you can protect yourself from this is by asking your conveyancing solicitor to formally ask the developer about any history of Japanese knotweed on the site. This means if they are aware of Japanese knotweed being present or being previously present on the land then they legally need to declare it to you, giving you an option to consider your purchase.

Do builders and developers need a Japanese Knotweed Survey before development starts?

Unfortunately, builders and developers don’t need to have a Japanese Knotweed survey completed on land before development takes place. If there is concern that there may be Japanese Knotweed present on the site then it is advisable that a survey is conducted quickly to establish if there is Knotweed, and the extent of it as this can save a developer time and money along the way. Knotweed surveys can be conducted by an NPCT qualified Knotweed specialist, ecological experts or chartered surveyors and a survey can influence if the land is purchased and what the recognised removal or control plan would be to allow construction to start.

Some standard land surveys will not identify if there is Japanese knotweed present so it is always better to arrange a specific survey from an NPCT qualified Knotweed specialist as it could save you a lot of time and money further down the line.

Is planning permission required to build on land with Japanese knotweed?

Planning permission is required before all building development can take place in the UK. Local councils will have policies in place regarding Japanese knotweed and development sites, as well as being aware of where it has already been identified which can be helpful in your planning process. It is a criminal offence under the Wildlife and Countryside Act 1981 to ignore the presence of Japanese Knotweed and move soil contaminated with its roots and enzymes and it can result in a heavy fine and even imprisonment.

If a developer is aware of Japanese knotweed on their development land they need to make specific planning conditions alongside their planning application to show they have factored the removal and control of it into their building plans. This planning conditions will include an assessment of the control options provided by the knotweed specialist, it will include measures for the completion of any control or removal methods, also including how site workers will prevent the plant from spreading further.

Does Japanese knotweed have to be removed before building work starts?

It will depend on how widespread and severe the Japanese Knotweed is. If it is in an isolated position where building work doesn’t commence until the later stages of the project then the control removal method can happen alongside the initial construction starting.

Large and established infestations of Knotweed can be deceiving and their underground root system is often wider spread than it appears above ground so it is imperative that you use an NPCT qualified Knotweed specialist to assess how widespread it is before building work begins. Japanese knotweed can disturb and exploit any weaknesses in foundations whilst searching for a route to moisture and sunlight so you always need to be aware how far the roots have spread underground before any building work begins.

How will Japanese Knotweed affect the value of a property?

if Japanese knotweed is discovered on the land a house has been built on it can impact its value by as much as 20%. It is imperative as a developer that you have a Japanese Knotweed survey conducted if you have any suspicions the plant is present anywhere on the development land. If you are buying a new home always ask your conveyancing solicitor to formally ask the developer to provide any information about Japanese knotweed on the site which means they legally have to declare it and you can make a decision if you still want to proceed with your purchase.

Do you have to declare Japanese Knotweed is present if you are selling your property?

You should make any potential buyer of your property aware about the presence of Japanese Knotweed as you can be liable for misrepresentation. If you live in a property or own land affected by Japanese Knotweed then you are legally responsible to ensure that it doesn’t spread to neighbouring properties or land. If the Knotweed is not controlled and allowed to spread the owner of the land will be liable for significant fines and, or imprisonment.

Does Japanese Knotweed deter developers from buying land to build on?

The answer to this question is yes and this is down to the complications it causes including; the cost of planning conditions as well as the removal and control costs, the delay to construction and that a large majority of people will be put off buying a property where there is or was Japanese Knotweed present, regardless if it has already been treated or removed.

If you are applying for a mortgage do you need to tell your mortgage company there is Knotweed present?

Yes, on your mortgage application you should tell them that the property you are looking to buy or remortgage has Japanese Knotweed as it is known as an invasive plant that can cause damage and impact the value of a property, as well as it sometimes taking several years to eradicate.

Mortgage lenders are cautious with properties that are affected by Japanese Knotweed, however, it isn’t impossible to get a mortgage. Their main concern is that a property with knotweed could be at risk of damage posed by the plant if the construction and foundations aren’t sound as well as the issues and reluctance of potential buyers when trying to sell the property further down the line.

Do you need to tell the Council if you have Knotweed on your property?

It isn’t an offence to have Japanese knotweed on your land and it is not a notifiable weed, however, under Section 14(1) and (2), of the Wildlife and Countryside Act 1981 it is a criminal offence to plant Japanese knotweed or otherwise cause it to grow in the wild or spread onto neighbouring land.

How quickly will Knotweed spread?

Japanese Knotweed can grow up to 20cm a day and in the height of its growing season and its stem can reach up to 3 metres, sometimes 4 metres high. Underground, the roots, rhizomes grow rapidly and can spread up to 7 metres horizontally and 3 metres deep.

Should you buy a property if it has Knotweed?

If the property you are looking to buy, or any adjacent properties or land has knotweed then you should be cautious about proceeding with your purchase. There are costs associated with the control and removal of Knotweed, as well as influencing if you will get a mortgage, or if you will be able to resell the property at a later time. We would always advise that you ask a Japanese Knotweed Specialist who is NCPT qualified to come to the property you are looking to buy and assess and advise you. If you go ahead with your purchase then you will have a legal responsibility to make sure it doesn’t spread onto neighbouring land.

Green Leaf Remediation Services

Green Leaf Remediation cover the whole of South Wales (including Swansea, Cardiff and Newport), West Wales up to North Ceredigion & Powys and throughout South Glamorgan & Gwent & Tenby. We carry out contracts in the West Country, as far North as Shropshire and into the Midlands & Birmingham areas.

We are a fully qualified Japanese Knotweed Certificated Surveyor (JKCS) and we specialise in controlling Japanese Knotweed, other invasive plants and ‘general nuisance weeds’ which are found in the UK for residential and property development sites.

Our Qualifications & Accreditations

  • City & Guilds NPTC Level 2
  • Principles of Safe Handling & Application of Pesticides (PA1/PA6)
  • Principles of Safe Handling & Application of Pesticides near water (PA6AW)
  • Herbicide Stem Injection
  • Property Care Association
  • The Control & Eradication of Japanese Knotweed Surveyor’s Training Course
  • Qualified Technician (PCAQT) in Japanese Knotweed
  • Accredited Surveyor in Japanese Knotweed

Contact us today on 01269 591651 if you think, or are concerned you may have Japanese Knotweed present on your Property or Development Land and we will be able to answer any questions you may have or arrange a free site survey for you.

We also provide tree services, such as pollarding, crowning, pruning, felling, through our NPTC chainsaw operators, all of whom possess a vast amount of experience in the forestry industry.