Mortgage Issues caused by Japanese Knotweed
Why is Japanese Knotweed considered so problematic?
Japanese Knotweed is listed on schedule 9, part 2 of The Wildlife & Countryside Act 1981, making it an offence under section 14(2)(a) of the Act to ‘plant or otherwise cause it to grow in the wild’. It is an invasive and potentially destructive plant, that in certain conditions has the capacity to cause damage to poorly constructed and very old outbuildings, drains, paths, underground services, cause heave in tarmac or poorly laid concrete surfaces. It is widely considered as the most invasive non-native species of plant within the UK & Ireland today.
Originally introduced into Britain as an ornamental garden plant over 150 years ago, with no natural pesticide and being able to grow unhindered within poor soil conditions, due to the aggressive growth pattern it has been allowed to spread rapidly throughout the country at an alarming rate. Fully mature, it can grow up to 8’- 9’ and will suppress the native vegetation whilst creating a rhizome network (root system), several metres both vertically and horizontally beneath the surface. Because of numerous cases having gained nationwide publicity in recent years, the existence of Japanese Knotweed on or close to a property is likely to have an unfavourable impact on future property sale/purchase.
Should you have any thoughts of selling your home or another property, irrespective of how small the infestation we would strongly recommend you adopt a pro-active approach to having the infestation assessed and treated by a suitably qualified professional. Conversely, we would advise anyone who is interested in purchasing a property affected by Japanese Knotweed to proceed as normal. Providing there is a treatment plan in place by a fully qualified & reputable contractor which also has a 5 or 10 year independently written Insurance Backed Guarantee (IBG), then there really is not a great deal to be concerned about. It may actually work out to your advantage in the negotiating phase!
Take a proactive approach instead of a reactive one. It will undoubtedly pay dividends in the long run!


GET STARTED TODAY
Whilst the previous ‘risk categories’ detailed above) were used as the framework for the mortgage lenders to decide on whether to approve or decline a mortgage application, it is fair to say that the structure was outdated and not fit for purpose. The so-called ‘7m rule’ focused more on what has been demonstrated to be an overstated risk of Japanese knotweed to buildings, rather than its potential impact on amenity (we now know that the roots seldom spread more than 3m laterally).
New Assessment Process
The new assessment process enables the valuer or surveyor to carry out a structured assessment, that leads to an objective categorisation. It is a more a definitive guide as to the full extent of an infestation and allows the ‘real impact’ of any given infestation, relative to its location and the specifics of the affected property to be established.
Although there are similarities to the assessment process, instead of the previous risk categories, the new guidance is focused on ‘Management Actions and will focus on matters such as loss of amenity space and actual damage to structures. The previous 7m rule of Japanese Knotweed being visible beyond a property boundary, has been replaced with 3m. The main objective of the Management Category assessment process is to provide consistency across the residential property market so that all stakeholders can understand the significance (or lack of) of Japanese Knotweed at or near any given property.
The ‘new’ categories are detailed below:
Management Category A – Action required.
Management Category B – Potential significant impact. Action required.
Management Category C – Low Impact
Management Category D – Limited Impact.
Based on a detailed site assessment, given the foregoing criteria, we have deemed the property in question fits the criteria of Management Category D – Limited Impact.
Client note – We anticipate that it’s highly likely any property deemed to be management category A or B, will almost certainly trigger the requirement for a Japanese Knotweed Management Plan (JKMP), supplemented by a 5 or 10-year Insurance Backed Guarantee (IBG) (again, that’s not conclusive, it’s merely what we foresee will happen sooner or later). As we advance with time, we also predict that an infestation fitting the criteria of a management category C & D is far less likely to be an issue for the lender. There is no doubting that 2022 (and maybe even 2023), will be a transition period. Only time will tell.
Before & After
