Our research shows that the blight of Japanese knotweed has wiped an estimated £11.8 billion off the current value of the UK housing market, as it continues to spread across the country making homes more difficult to sell.
We estimate that approximately 4% of homes are affected by Japanese knotweed, either directly or indirectly (i.e. neighbouring an affected property), impacting their value by an average of 5%. This means approximately 890,000 households across the country are suffering a typical reduction in value of £13,200 due to knotweed, knocking £11.8 billion off the value of the nation’s homes.
Unsurprisingly, the main concern for anyone dealing with knotweed on their property is preserving its value as much as possible – and the best way to do that is to excavate the root system. Our data shows that buyers and sellers of affected properties are increasingly turning away from traditional herbicide treatments and opting for excavations, where the plant’s extensive rhizome system is dug out of the ground, in a bid to limit diminution in property values and manage the risk posed by the plant. Almost 70% of our customers opted for excavation of Japanese knotweed during 2021, an increase of +10.6% on the previous year, while the proportion of herbicide treatments has declined by -17.7% over the same period.
A decade ago, herbicide was by far the most popular way of dealing with knotweed on residential properties, but herbicide treatment is increasingly being recognised by homeowners as a control method. Although above-ground growth may disappear, the root system beneath the ground is often induced into dormancy meaning it’s capable of re-growing in the future – particularly if the ground is disturbed by landscaping or building work. This makes buyers more wary of possible regrowth, which has a negative effect on the property’s value. If an infestation has been professionally excavated on the other hand, with an insurance-backed guarantee to satisfy mortgage lenders, it is possible to restore the property value to close to the original value.
Excavation costs can be reduced by opting for a combination treatment and removal method, DART™, which removes the bulk of the knotweed crowns and rhizome system, massively reducing the plant’s vigour and stimulating growth of any small pieces of remaining rhizome, making them more susceptible to herbicide treatment the following spring. The excavation element can be carried out during the winter months, allowing for full use of gardens during the summer.
Whatever your situation or budget we can provide a cost-effective solution to your knotweed problem that helps protect the value of your property. Contact us today to arrange a consultation.