What is Japanese Knotweed?
Japanese knotweed (Fallopia japonica) is a herbaceous perennial plant that looks like bamboo. When it first arrived in Europe in the nineteenth century it was considered as an ornamental plant.
It is now identified by the Environmental Agency as “indisputability the UK’s most aggressive and invasive plant”. Its emerging roots can infiltrate and weaken brick, tarmac, and metal piping, causing costly damage to everything from buildings to roads.
Japanese Knotweed is classed as controlled waste and must be disposed of safely at a licensed landfill site according to the Environmental Protection Act (Duty of Care) Regulations 1991.
Why is Japanese knotweed a problem when purchasing property?
If left untreated Japanese knotweed can instil itself and cause great damage to residential and commercial properties.
Japanese knotweed will grow with enough force to damage fences and even cause walls to fall. It will also grow up and through vents and air bricks and once it is in cavity walls it has the force to push the two walls apart.
Mortgage lenders can refuse a mortgage to people buying a property with live Japanese knotweed growing on the premises due to the extent of damage it can cause. The knotweed is classed as a risk to their security on lending.
Whose responsibility is it to remove Japanese Knotweed?
In the case of Waistell v Network Rail Infrastructure Ltd 2013 the claimants made a claim against Network Rail, which owned the land immediately behind their properties.
Japanese knotweed had been present for a minimum of 50 years on the land owned by Network Rail. The neighbours complained about the spread onto their land. A judge awarded Williams and Waistell damages, and declared the Japanese Knotweed a natural hazard which has affected the ability to make full use of the land.
What this means for you is that Japanese knotweed becomes your legal problem if it’s affecting your property. It is also your responsibility to have it treated, removed and disposed of.
In the case of Smith v Line 2018 the dispute was resolved after thirteen years, when a judge ruled Ms Line had allowed Japanese knotweed to spread onto the Smith’s property. As a result the value of the claimants’ land had been reduced by 10%, from £800,000 to £720,000. Ms Line was ordered to pay to treat and remove the Japanese Knotweed.
Is there a cure for Japanese Knotweed?
Treating Japanese knotweed is quite expensive, but it can be done by a professional. An area under 50m2 can cost around £1,000 to £3,000 to treat. The treatment is usually carried out over several years by a qualified professional.
Contrary to all the alarming information about Japanese Knotweed a recent study carried out in 2018 by the University of Leeds, found no evidence that Japanese knotweed is especially damaging when compared to other plants.
Mortgage Lenders have been known to lend of properties with Japanese Knotweed as long as there is a treatment programme in place.
As always when purchasing a property it is paramount to remember the Caveat Emptor rule of “Buyer Beware” and to check the land upon which you intend to buy as thoroughly as possible.