Knotweed (Japanese Knotweed)

Japanese Knotweed can cause significant damage to tarmac and paved areas, and can be costly to treat once it has taken root.

Left unchecked, Knotweed can also cause a reduction in the value of your property following an increased risk of flooding, as dead Knotweed plant matter is washed into water channels and drains. In more rural areas, further environmental problems can be caused by related soil erosion and instability of river and stream banks on or near your property.

Knotweed was introduced into Europe in the 1800s from Asia, and was originally intended for use as an ornamental plant, growing to 2-3 meters in height. Not only is Japanese Knotweed ugly, it is invasive and spreads quickly. Knotweed is particularly virulent in the UK in Europe because it lack the predators and diseases which keep it in check in it's native environment.

It is an offence in the UK to cause Knotweed to grow in the wild.

Knotweed's effect on the value of your property

The Royal Institute of Chartered Surveyors (RICS) have proposed guidelines to assess the impact knotweed's presence should have on the price of a house, given its destructive tenacity.

Stories of the extreme measures proposed to deal with Japanese Knotweed regularly cause sales to fall through when the weed is discovered by the would-be buyer, but RICS have stated that despite the difficulty of removal, Knotweed "needn't be a life sentence for a property".

In one example, a Hertfordshire couple's home lost £250, 000 in value when the weed was found. The property had originally been valued at £305, 000. The owners were advised that to destroy the weed, not only would their property need to be demolished, the soil would also have to be removed, up to a depth of 10ft!

It is cases such as this that have led RICS to take action to identify and clarify not simply the risks associated with Knotweed, but practical solutions to the problem.

Speak to a Qualified RICS Surveyor today for more information, call 0330 660 0286 and book a Home Buyers Survey for your property.