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Cutting Through Complexity


8th October 2018

Gemma James discusses the issues that knotweed can cause in the Essence October 2018 issue.

Four letters can make a big difference!  A weed might be unsightly, but if an expert declares it to be “knot” weed, you have a much more tangled problem!  Legal risks and obligations affect owners and tenants of residential and commercial property alike, so keep that in mind as you look around your land and know when to seek legal advice.

Despite a 2018 study by the University of Leeds and US engineering firm AECOM finding no evidence that its roots can crack concrete or undermine foundations, Japanese Knotweed can cause property owners no end of difficulties.  Here are just a few:-

  • Maintenance is burdensome because the plant can grow up to 10 centimetres per day in the summer. 
  • Some mortgage lenders refuse to lend on affected properties while others demand that any knotweed within 23 feet of buildings is destroyed.  Their valuers will be on the lookout for it if you are buying or re-mortgaging, so it can put transactions and funding at risk because it will devalue the property.  Solicitors acting for lenders will have to advise the lender if any enquiries reveal there is knotweed at or in the vicinity of the property.
  • The Court of Appeal ruled in a case against Network Rail this year that if knotweed spreads from your property to your neighbour’s, you could be liable to compensate your neighbour.  The mere presence of its roots is sufficient for a claim against you even before any physical damage has occurred.  If you are on the receiving end of such ingress from a neighbour, this case gives hope, but most likely a long and costly claim and/or remediation process.
  • If you are trying to sell your property, you will be obliged to disclose any awareness you have of the presence of knotweed on the standard property information forms which can cause buyers to withdraw or lower their offer.  Failure to disclose information of which you are aware can lead to a future claim for misrepresentation from your buyer.
  • A property afflicted by knotweed is less appealing to tenants, who may ask for rent reductions and treatment to be paid for or provided by the landlord.
  • Buildings insurance may be harder to obtain because insurers shy away from properties with an arguably increased risk of damage.  RICS guidance indicates a potential risk of damage within seven metres of knotweed roots.
  • If you try to handle and dispose of knotweed yourself, you risk criminal and civil viabilities for failure to comply with legislation.  Fines and even imprisonment are possible if the appropriate regulations are not followed for management, treatment and disposal.
  • The local authority can serve notice on you requiring you to remedy the condition of land when it becomes aware of its presence and any consequent risk to adjoining land.  Failure to comply can lead to prosecution.

If you become aware of Japanese Knotweed on your land, its market value will be diminished by this blight and you are best advised to instruct a professional company to advise on remediation.  This will typically be a treatment programme stretching over several years to manage it effectively.  It is wise to ensure the company will offer a guarantee for its work.  Often a clear management programme will be sufficient to convince buyers, lenders and tenants to proceed and to reduce your risk of claims from neighbours, but someone will have to pay the treatment costs.

If you are a tenant or purchaser, make sure you arrange a thorough survey of external areas before committing to a property.  Tenants should carve maintenance and eradication out of their lease obligations and consider other concessions from the landlord such as rent reductions and remediation programmes at the landlord’s cost.  Buyers should assess whether a price reduction or initial remediation works are appropriate from a seller, and ensure that the benefit of any treatment guarantees and management plans pass to the new owner.  It is worth checking that the knotweed consultant is registered with the Property Care Association. 

If you discover knotweed on your land, your surveyor might find it has come from next door.  In this event, remediation costs could potentially be shared with your neighbours, or even wholly attributed to them.  If it has not spread next door from your land yet, take action fast, not just to protect the value of your property but also to prevent claims by your neighbour.

When a weed is knotweed, pay heed faster than the speed of……knotweed!

Gemma James is a Partner in the Commercial Property Department at Mundays LLP and can be contacted on 01932 590645 or gemma.james@mundays.co.uk.

The contents of this update are intended as guidance for readers. It can be no substitute for specific advice. Consequently we cannot accept responsibility for this information, errors or matters affected by subsequent changes in the law, or the content of any website referred to in this update. © Mundays LLP 2018.

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