Japanese Knotweed

Japanese knotweed is a giant weed which grows at a rate of 10 centimetres per day in any type of soil. As the name suggests the plant originated in Asia where it is more controlled due to the existence of natural diseases and natural enemies that limit its growth.

The United Kingdom does not have the pests and natural diseases that control Japanese knotweed hence its growth at an alarming rate. The weed has been known to cause damage to building structures and sub structures. It can typically cause damage to tarmac and paving areas, walls and building foundations.

Owing to the fact that the weed can grow through walls, tarmac and concrete it causes real concern for property owners.

Furthermore, majority of the lenders are reluctant to offer a mortgage where Japanese knotweed has been deemed to be a threat to the property.

As reported on the BBC News, a couple in Hertfordshire saw the value of their house drop by £250,000 due to damage caused by Japanese knotweed. Their house had originally been valued at £305,000 but the value dropped to just £5,000 due to the damage caused by the invasive weed. The couple had been advised that unless their detached house was demolished and 10ft of soil was removed from beneath the foundations it would be impossible to sell their property.

It is not all doom and gloom however with the Royal Institute of Chartered Surveyors (RICS) saying that this is not necessarily a “life sentence”. The body is currently proposing a Risk Assessment Guideline on how the weed’s presence can be taken into account when assessing the value of a house with a view to limiting the number of sales that fall through owing to the presence of the weed.

RICS does add that while the plant is hard to control, with the right treatment “it needn’t be a life sentence for a property.”

Posted by Tuiya Tembo, a property lawyer working in both Leeds and Wakefield. Tuiya can be contacted on 01132570526 or via email at tuiyatembo@chadlaw.co.uk