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japanese knotweed

Japanese Knotweed: Would you know one plant from another?

Would you know one plant from another? I certainly don’t: They all look green to me!

I have endless arguments in the Summer with my husband when I sort the flower boxes only to forget to water them – he quips that he has no idea how I can keep 3 children under 6 alive but not a few plants!

So I definitely have sympathy with home owners who may or may not know if they have Japanese Knotweed on their properties.

The problem however is that whether a home owner is aware or not, the impact on properties can be significant.

This is because it is believed that the plant’s deep roots mean it has the potential, if unmanaged to grow to 3-4 metres in 10 weeks and if found within 7 metres of a property, to cause major structural damage to them.

The removal of Japanese Knotweed from properties is now a legal requirement making the cost of its disposal expensive and time consuming. Eradicating it can cost well over £1,000 per square metre and, as a controlled waste, it can be expensive to dispose of the ‘contaminated’ topsoil. It can also take several years to eradicate.

There have been several cases reported in the media  of late on the difficulties caused by Japanese Knotweed as follows.

The principle that adjoining owners could be sued for encroachment of Japanese knotweed was established by the court of appeal in a 2018 case by Stephen Williams and Robin Waistell, who owned two adjoining bungalows in Maesteg, south Wales. They claimed successfully against Network Rail, which owned the land immediately behind their properties following complaints made to them about the encroaching Japanese Knotweed since 2013.

Since then, the court of appeal ruled that a homeowner could recover damages for the loss of value of their property from having had Japanese knotweed and the stigma caused by the same, even if it had been treated in a 2023 case by Marc Davies against Bridgend County Council.

More recently, the London Central County Court in the 2023 case of Downing v Henderson found that a seller could be liable for damages and legal costs for misrepresenting to the buyer whether there was Japanese knotweed at the property.

As a result of cases such as these, if there is Japanese Knotweed on your property or near it, then a mortgage lender may be unwilling to lend because of the significant issues Japanese Knotweed can cause for the use, enjoyment and value of the property and the potential for resale or remortgage in the future.

Here at Compton’s Solicitors we therefore strongly advise our clients as follows:

  1. to obtain an independent Japanese Knotweed survey prior to purchase especially if you have any concerns regarding the same.
  2. to fully disclose the existence of Japanese Knotweed if you are aware of its existence if selling a property. Often having an insurance backed Japanese Knotweed treatment plan can allay any fears a lender of buyer may have concerning the same.
  3. Not to tick the box on the property information form saying you have no Japanese Knotweed unless you have had a survey categorically confirming it is not on your property or within 7 metres of it. The safe way to proceed if you don’t know either way is to tick the “not known” box.

And finally … to remember to water the plants, whether we know what they are or not!

Susanna Levingstone - Senior Associate Solicitor Comptons Solicitors
About the Author
Susanna Levingstone, Solicitor, Residential Property

Specialises in: Property Conveyancing, Large Rural Estates, Lockout Agreements, Auctions, Options and Time-critical Contract Races, Attended Exchanges, Acting for First Time Buyers, Property Dealers & Developers, Cohabitation Agreements

If you would like to speak to someone regarding Japanese Knotweed, or require further information on any Residential Property matter, please contact Susanna Levingstone in the Residential Property department at Comptons Solicitors LLP. ( / 020 3830 6276).