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03 Feb 2022 < Back

New Guidance on Japanese Knotweed for Valuation Surveyors: Are you ready?

On Wednesday (26th January) we saw the launch of new Guidance from RICS on the assessment of Japanese knotweed impacts on residential property. This is an important event for our PCA members who will need to be prepared to answer questions from vendors and purchasers etc., about the new scheme. Eventually we hope that estate agents/vendors and surveyors/lenders all have a common understanding of how to select the new risk categories (now called Management Categories) and what this means for their clients.

Are you Ready for the NEW Knotweed Guidance?

The new RICS Guidance is available now but not due to be implemented for 8 weeks - 23rd March - so we have a reasonable period in which to prepare and start complying with the new risk assessment scheme.  So let’s discuss why the new Guidance has been produced, how it works and any potential problems we can anticipate when compared with the current scheme (IP27). We will dive into the whole document in detail when we host our upcoming webinar on 24th February, AND we have produced our own Guidance Note (for valuers and property surveyors) to support the RICS publication (both documents free to download via the button below). But for now we thought it would be useful to focus on a couple of key areas - those which we think could lead to some confusion during the IP27 - GN2022 interregnum.

View Guidance Notes >>

Background/Drivers for change

Some would argue that the old phrase “if it ain’t broke don’t fix it” applies to IP27/2012. When it was published it brought order to a market that, as far as Japanese knotweed was concerned, was disorganised and confusing. Before 2012, almost anyone with a knapsack sprayer was claiming to be an expert in Japanese knotweed control and many made claims for ‘guaranteed eradication’ in weeks rather than years! Then two things happened more-or-less simultaneously; firstly the PCA Invasive Weed Control Group was formed to provide buyers and lenders with a quality benchmark of competence and professionalism which in turn enabled contractor guarantees to be underwritten by independent insurance policies. Secondly, RICS published IP27, a framework for classifying knotweed stands on properties in terms of proximity to buildings (and other structures) and boundaries. This gave lenders a framework to use to assess risk and subsequent lending decisions (mortgageability). And it worked! That is to say it gave banks and Building Societies the confidence to lend fully aware of the scale of risk, but also aware that even in the highest risk categories, there were remedies available via contractors operating to strict quality standards/Codes of Practice. Nevertheless, time passes and it became clear that the IP27 scheme, whilst it was effective, could lead to vendors being unduly disadvantaged in certain circumstances. RICS produced a draft revision as long ago as 2016 so this weeks launch of new Guidance from RICS, presenting a change in the way Japanese knotweed is recorded, is the result of a lot of work (and new research) behind the scenes! The new scheme for risk assessment is no longer based on distance from buildings/boundaries but on actual impacts. Now let’s look at the key changes…

7m or 3m and "if you can’t see it, you can’t record it!"

In 2012 the emphasis for Risk Assessments was on distance (from buildings/boundaries). This is because it is known that Japanese knotweed rhizomes can travel long distances; radiating out from the edge of stand and/or penetrating to great depths in the soil. The figure of 7m was chosen as a benchmark, but over time it became clear (and was later confirmed by an industry questionnaire run by independent researchers) that this was a ‘worst-case’ metric; more typically, stands of knotweed will spread their rhizome network up to 3m laterally (but it remains the case that 7m or more is possible in individual cases). In effect what surveyors had been doing for many years was assuming that Japanese knotweed could impact a building over distances of 23 ft. The new guidance removes this guesswork and asks surveyors only to report on where the knotweed is and what it is doing!

The Knotweed management categories...

If it is causing a direct physical impact on buildings or patios/drives etc., – that’s the highest Management Category ‘A’. If it’s in the garden and impacting amenity use (blocking access or preventing normal use of a lawn or recreational area) – that’s the next level, Management Category B. Otherwise, if it is within the property boundary, it's Management Category ‘C’.  Lastly, if its off-site but within 3m of any boundary, it Management Category ‘D’. This is a simple summary but I hope you get the idea. The other important point to note is that these Categories are based only on what the surveyor can see above ground. When we are talking about controlling the knotweed we expect management plans to include due consideration of the rhizome ‘buffer zone’ but that comes later in the process.

Some subjectivity, but a clear set of guidelines

With this new guidance, RICS has stated their intention to keep Japanese knotweed firmly on the radar as a risk to property condition, use and value. In short, they don’t want to lose the benefits of IP27 we mentioned above. From the PCA’s point-of-view, we are also focused on preventing the wider environmental risks of Japanese knotweed spreading from residential properties. But we must recognise that in transitioning from the 2012 to the 2022 scheme we have gone from a purely objective assessment process (distance), to one which involves an element of surveyor judgment. This shouldn’t give RICS qualified practitioners any problems. They exercise such judgments all the time in relation to other things. For Japanese knotweed, they now have a clear set of guidelines within the RICS Guidance Note and PI insurance to back their decisions if ever required. But PCA members who are CSJK qualified may have to defer judgment in some cases as, whilst they are experts on Japanese knotweed identification/management etc., they are not necessarily otherwise qualified or insured!

Take away message

We are actively supporting the RICS campaign to raise awareness of this new Guidance. Crucially the new guidance ensures that everyone in the Property sector remains vigilant about its potential to cause damage to both buildings and hard surfaces, and more general nuisance impacts in amenity areas. We hope to have a big response to our webinar in 4 weeks' time when we will be able to delve deeper and hopefully answer all your questions! In the meantime if you need any advice at all on invasive weed problems, we are here to help!

More Info about the Webinar >>

View Guidance Notes >>

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