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I penned this article a few years ago but in the past two weeks I have had two clients have to deal with this nasty little fellow, one purchaser and one vendor. So I thought it timely to share this again.

Japanese Knotweed (Fallopia japonica) is an invasive species of plant, alien to these shores.

The destructive bamboo like plant is notoriously fast growing and has an amazing ability to colonise areas very quickly, having been known to grow up to nearly a foot a week! It can grow
through tarmac, paving, foundations and buildings causing structural damage. The thug like plant is most difficult to destroy and even a small cutting can cause mayhem. It is the
Terminator of weeds!

It is an offence under the Wildlife Order (NI) 1985 to plant or even allow it to grow in the wild. A landowner is under no obligation to treat any established infestation on their land but it is an offence if the weed spreads to neighbouring land. The landowner has a duty of care not to allow the weed to spread and could be liable for any damage or the costs of eradicating the infestation on the neighbour’s lands.

This innocuous looking weed can not only cause structural damage but in some cases the very mention of species can have both potential buyers and lenders both running from the transaction.

Smaller lenders have been minded to decline mortgage applications where this culprit is present or even present in adjacent premises. Bigger lenders are now following suit unless the remedial work is undertaken before the mortgage is advanced. Potential problems of obtaining buildings insurance is often cited by lenders as the reason for declining applications.

Treatment can be costly as the species is not affected by normal pesticides and removal costs are exacerbated as digging the weed out of the ground to remove its sub-structure can give rise to re-location of pipes and drainage. Also the Waste Management Regulations (NI) 2006 (as amended) requires an occupier of domestic properties to ensure that any transfer of the controlled waste by an authorized person. This can be an expensive undertaking.

If you are about to place your house on the market, check your property for any signs of this invader, as it is easy to spot and if in doubt call in expert advice in relation to removal.

Check your home insurance as to whether the costs of any treatment would be covered (it may not – check your policy exclusions! ). It is imperative to have the infestation treated without delay as some treatments can take time to bed in and keep all paperwork as the problem and treatment would have to be revealed in replies to pre-contract enquiries to any potential purchaser.
If you are buying, don’t panic (too much!) as the surveyor will be aware of the risk that the plant poses and of what the weed looks like. However, if the weed is present you may have to liaise with your proposed lender as to their lending policy in such circumstances and with your vendor to ascertain whether there has been any initial treatment and whether there is a commitment (and payment!) to an ongoing treatment programme.


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