What is Japanese Knotweed?
Japanese knotweed can be a landowner’s worst nightmare. Developers and investors need to be aware of the risk it poses to their investment.
It is a plant native to Japan. Whilst originally introduced in the UK as an ornamental plant, the perfect weather conditions have caused it to spread rapidly and it is now classed as an invasive non-native species.
It can force its way up through concrete and tarmac and can pass under walls and houses, causing tremendous damage to buildings and foundations. Treating Japanese knotweed is time consuming, costly and it is notoriously difficult to eradicate.
The problem for developers and investors is that funding will not be available from lenders if Japanese Knotweed is deemed to pose a risk. New policies set out by the Council of Mortgage Lenders mean that the valuation of a property where Japanese knotweed is growing within 7 metres can be greatly affected.
House builders in particular need to be vigilant to the risk it could pose to plot sales.
The case of Waistell v Network Rail Infrastructure Limited is a reminder that developers and investors need to be aware of the risk posed to their investment, even if the knotweed is not located on their land, but on adjoining land.
Waistell v Network Rail Infrastructure Limited; Williams v Network Rail Infrastructure
Mr Waistell and Mr Williams owned two neighbouring bungalows. Their rear walls formed the boundary with an access path and embankment owned by Network Rail, at the base of which was an active railway line.
A large stand of Japanese knotweed was present on the embankment. As the plants were within 7 metres of the rear wall of the bungalows it was considered too risky for lenders without a proper remediation programme, supported by an insurance backed guarantee. Network Rail had known about the Japanese knotweed since 2008 but did nothing to remediate its effects on the neighbouring bungalows.
Mr Waistell and Mr Williams issued claims against Network Rail.
The judge in the County Court held that, because the value of the two bungalows was affected by the presence of Japanese knotweed, Network Rail had committed a “private nuisance” even though the knotweed had not yet encroached on to their properties. Mr Waistell and Mr Williams were awarded damages based on the reduction in value of their homes.
On 3 July 2018 the Court of Appeal upheld the decision against Network Rail. However, they based their finding of nuisance on the fact that the Japanese knotweed rhizomes (similar in their effects to roots) had already spread underground, encroaching onto Mr Waistell’s and Mr Williams’ land. The presence of the rhizomes, even before the knotweed has grown, affected the amenity of the land and placed a burden on the landowners to bear the expense and difficulties of removing the knotweed contamination and would cause difficulties should they wish to develop their land.
What should you do?
Before buying land, consider whether a specialist survey should be undertaken to ascertain if there is knotweed present on the land, or in the vicinity. If knotweed is present consider the impact. Apart from the cost, the process of removing knotweed can take several years.
A proper remediation strategy which is fully documented, carried out in accordance with industry guidelines and backed by a guarantee is recommended. Without it, funding could be an issue.
If you already own land affected by knotweed, the Waistell case is perhaps a warning that simply containing the knotweed on your land may not be enough. It may be spreading unseen onto neighbouring property and you may need to consider remediation.