We are independent, professional and thorough building surveyors in Cambridge and HaverhillWe are independent, professional and thorough building surveyors in Cambridge and HaverhillWe are independent, professional and thorough building surveyors in Cambridge and HaverhillWe are independent, professional and thorough building surveyors in Cambridge and HaverhillWe are independent, professional and thorough building surveyors in Cambridge and HaverhillWe are independent, professional and thorough building surveyors in Cambridge and Haverhill

We are specialist building surveyors in Cambridge and Haverhill focusing on residential properties and listed buildings

Insider Guide: Japanese knotweed

Spring is the time of year when the dreaded Japanese knotweed starts to rear its head – or buds in this case – and we realise just where it’s been hiding all winter.

Japanese knotweed is a tricky foe as it dies off during the winter months and looks very similar to the wilderness that surrounds it, making it difficult to spot. But as spring rolls around it bursts back into life and can start to cause problems for homeowners across the country. Given this, at Anglian Home Surveyors we like to keep reminding our clients of what they’re up against and what the implications of this invasive species can be.

The first thing to be aware of is what Japanese knotweed looks like, because identifying it early can lead to quicker eradication. So what are we supposed to be looking out for? Japanese knotweed has several stages of growth, each of which has certain identifiable features including the root buds, stems, leaves, flowers and rhizomes (or roots).

Why is it important to know what we’re up against?

We believe that it’s important for conveyancers to make their clients aware of Japanese knotweed not only because it can potentially damage buildings, but also because there are legal implications for properties where the plant is present. While it is not an offence to have Japanese knotweed on a property, nor is its presence reportable, it is the landowner’s responsibility to ensure that it does not spread to adjoining land.

There are three pieces of legislation that provide powers to control the spread of Japanese knotweed:

Wildlife & Countryside Act 1981, Section 14 3
Under this Act it is an offence to plant or otherwise cause any plant listed in Part 2 of Schedule 9, including Japanese knotweed, to grow in the wild.

Environmental Protection Act (EPA) 1990, Section 34 4
This Act states that Japanese knotweed is classed as ‘Controlled Waste’ and must safely be disposed of at a licensed landfill site. Breach of this Act can result in an unlimited fine and/or a two-year prison sentence.

Anti-social Behaviour, Crime and Policing Act 2014 5
This Act gives the police and local authorities the power to serve a community protection notice on a body or individual requiring them to prevent or control the growth of Japanese Knotweed. In order to serve a notice it must be proven that there is a persistent or continuing detrimental effect on the quality of life of those around them, and the failure to deal with the problem is unreasonable. Breach of a community protection order can lead to a fine up to £2,500 for an individual or up to £20,000 for an organisation.

In addition to these pieces of legislation, many local authorities also provide guidance via their websites on what to do if Japanese knotweed is discovered at a property.

The legal implications of Japanese knotweed aside, it can have a detrimental effect on a property. In particular it can cause structural issues due to its ability to exploit existing cracks in structures, including in patios, paths, pipes, culverts, foundations, brickwork and so on, as well as services, as it grows in search of nutrients, light and water.

As a result the Law Society revised the TA6 Property Information Form in 2013 to include a question (7.8) about whether or not the property has been affected by Japanese knotweed. If a vendor declares that the property is free of knotweed and it is later discovered, they may be liable for diminution in value and treatment costs. To treat only a few square metres of knotweed can cost between £5,000 and £10,000, and sometimes more if it needs to be removed quickly.

How can it be dealt with?

As homeowners are ultimately responsible for ensuring that Japanese knotweed doesn’t encroach onto neighbouring land, we believe that it’s important that they understand how it can be effectively dealt with. The treatment options include:

  • Chemical treatment
  • Relocation and herbicide programme
  • Reduced dig and herbicide programme
  • In-situ capping
  • On-site burial
  • Picking, screening and sorting
  • Excavation and removal
  • Biological control

Full details regarding all of the above mentioned treatment methods can be found in Groundsure’s Japanese knotweed guide, which also includes a range of videos.

Knowing who to turn to

Over the last ten to 15 years, more people have become aware of the problems that non-native invasive plants such as Japanese knotweed can cause. Recent newspaper articles and television coverage have ramped up the issue, leading to mortgages being refused and a spate of high-profile litigation.

As a result, there has been a flurry of new businesses coming into the industry and proclaiming themselves ‘experts’ in the field of invasive species eradication. Many companies have also added an ‘invasive’ sector in an attempt to boost flagging sales, and in a number of cases this is completely unrelated to their core business.

The lack of correct controls, accreditations and knowledge within a large proportion of these new companies poses a significant threat to both the domestic housing market and commercial development, two areas that are vital to ensuring the recovery of the UK economy.

Customers need to know that the companies they employ are operating to agreed standards and that the prices they quote can be for comparable works.

The Invasive Non-Native Specialists Association (INNSA) is the industry body for companies involved in controlling and eradicating invasive non-native species.

Membership demonstrates professional knowledge and understanding of invasive species and the best methods for eradicating them. Registration with INNSA provides members with a recognised accreditation backed by a comprehensive insurance scheme.

All works offered and carried out by an INNSA-accredited contractor/member to domestic customers will come with an insurance-backed guarantee designed to give peace of mind to homeowners and to ensure that in the event of a company ceasing to trade, all warranty commitments are honoured.

As a leading building surveyor in Cambridge, Raphael Stipic of Anglian Home Surveyors is affiliated with INNSA and experienced in identifying Japanese knotweed and assisting clients in managing and removing it in order to avoid falling foul of the law. Should you have any concerns at all about Japanese knotweed, please call Raphael on 01223 661439.


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