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RICS publishes new draft guidance for the assessment of Japanese knotweed

RICS publishes new draft guidance for the assessment of Japanese knotweed


The Royal Institute of Chartered Surveyors (RICS) has this week published new draft guidance for the assessment of Japanese knotweed on UK properties, which is now under consultation. This means surveyors and other property professionals will have the opportunity to comment and potentially amend the guidance ahead of its final publication later this year.

So, what are the main changes?

Firstly, the so-called ‘7 metre rule’ has been scrapped. This stated that if Japanese knotweed was growing within 7m of a building, a mortgage would not be offered without a Japanese Knotweed Management Plan (JKMP) in place. The new guidance is a bit more nuanced, sensibly aligning with the Law Society’s guidance on their TA6 form completed by sellers, with 4 categories:

A. Present on any part of property and signs of property damage

B. Present on any part of property, no damage to property but significant loss of amenity (i.e. can’t use much of garden)

C. Present on any part of the property but not having much impact

D. Not present on the property but is on neighbouring property within 3 metres.

Secondly, the new guidance recognises that while Japanese knotweed can cause damage, for example growing up through asphalt driveways, it’s unlikely to cause serious damage to substantial structures. This is a true and fair assessment. RICS is right to recognise that there can be a loss of amenity, i.e. use of the garden where it is growing and where it is treated with herbicide, but that can be minimised by using an excavation method.

Thirdly, the focus is more on ‘control’ than ‘eradication’, which is where our main concern lies. In our view the goal should always be eradication if possible – and by settling for ‘control’ the bar is lowered for the sake of a lower initial cost. Most homeowners and buyers will feel far less reassured knowing that knotweed is still present and alive on the property, even if herbicide treatment has induced it into temporary dormancy which could be broken at any time, particularly if building work takes place in the future. This would have a far more serious impact on the value of the property over the long term, than if the infestation was eradicated from the outset.

Environet Founder and MD Nic Seal, said: “On the whole RICS’ advice is cautious and sensible, while rightly recognising that in a vast majority of cases, Japanese knotweed is treatable with professional help – and with a management plan in place transactions should be able to proceed unhindered, with property values largely preserved.

“Despite the challenges, eradication of knotweed should always be the goal and most homeowners and buyers will want reassurances that the problem has been dealt with and knotweed isn’t going to rear its head at some point in the future.”

Click here to read the full draft guidance.

Robert Spaceman

“We had a large stand of bamboo removed, thinned, contained and replaced. The customer service has been first class. Joe and Jason were fabulous and kept me well informed at all times”.