New advice helps homeowners trapped by Japanese Knotweed rules

Japanese Knotweed is a plant that can wreak havoc for many homeowners. The fast-growing invasive weed is notorious for being difficult to kill and highly destructive. In previous years, many homeowners with Japanese Knotweed on their property have faced difficulties getting a mortgage. Some lenders would refuse to lend at all while others would require homeowners to pay for expensive treatments to eradicate it.

This has made it difficult and costly for homeowners looking to sell. And the invasive species’ damage doesn’t stop there; if found, it’s presence can wipe up to 15% off a property’s value.

However, updated guidance by the Royal Institution of Chartered Surveyors (RICS), which comes into force next month (March 2022), has abolished the ‘seven metre rule’ in favour of a more lenient approach that means surveyors can use their discretion when assessing the impact of knotweed infestations.

This new guidance means it should be easier to buy or sell a home that has Japanese Knotweed at or close to the property.

What has changed and why?

RICS says the advice “reflects an improved understanding” of Japanese Knotweed. It says, “The so-called ‘seven metre rule’ focused more on what has been demonstrated to be an overstated risk of Japanese Knotweed to buildings, rather than its sometimes-serious impact on amenity.”

RICS have said research has demonstrated, and it is now generally accepted, that Japanese Knotweed poses little or no risk of structural damage to robust buildings with substantial foundations such as dwellings, as opposed to less sturdy structures with shallow foundations, such as conservatories, garages or boundary walls.

There is also a recognition that the most appropriate objective when Japanese Knotweed is encountered is to ensure an appropriate level of control rather than to automatically strive for eradication. This will be good news for homeowners paying for expensive treatment programmes and worrying that the plant may never be removed from their land.  RICS go on to explain that in some circumstances, for example when construction is proposed, proper control may involve physical removal but in many domestic situations effective control can be achieved by the managed application of herbicides.

Commenting on the rule change, Paula Higgins, the CEO of the HomeOwners Alliance said, “This change is well overdue. RICS have been too slow to act on this and have failed to recognise the impact it has been having on homeowners’ lives and finances.

“The exaggerated response to Japanese Knotweed by surveyors has caused huge upset to homeowners who have been unlucky enough to find it at the bottom of their gardens. Our homes are our biggest financial investment and should be a place of solace – not a source of worry and dread.

“No responsible homeowner would leave Japanese Knotweed to grow out of control or leave it untreated, but this rule had created unwarranted fear for too long – and also created a mini-industry of firms providing expensive treatment programmes which homeowners needed to pay for if they wanted to sell their homes.”

What does this mean for mortgages?

The guidance from RICS follows a report by the House of Commons Science and Technology Committee in 2019 where MPs described mortgage lenders’ approach to Japanese Knotweed as “over cautious”.

In previous years, some lenders would only have to see the words Japanese Knotweed in relation to a property to decline a mortgage application. However, this position evolved over time with many lenders choosing to look at applications on a case-by-case basis. If the plant was found on someone’s land, lenders would typically require a specialist report on the weed being provided and a professional eradication plan being put in place which could cost thousands of pounds.

While RICS have announced their updated guidance, we haven’t seen a response from lenders yet. It’s not surprising; one expert explained that an immediate response would be unlikely as lenders will need to digest it and look at the implications for them. However, they also explained this doesn’t mean lenders won’t move their position and pointed to the “quite substantial movement” in the past.

How can I spot Japanese Knotweed?

It can be recognised for its lime-green bamboo-like stem, speckled purple and red. It has heart-shaped leaves with sprouts having a reddish tinge and turning a lime green. During the summer they produce clusters of creamy-white flowers. And the plant’s extensive roots can penetrate deep into the ground.


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