The free online JK-VIM tool enables surveyors, estate agents and property owners to check how much the value of a property may potentially be reduced if it is affected by knotweed.
It also offers revised valuations if a property is treated by herbicide or excavation and if it has a ten-year insurance-backed guarantee for the works
Environet UK developed the software with support from Expert Surveyors – a Royal Institute of Chartered Surveyors registered surveyor.
Earlier this year the Science and Technology Select Committee of MPs concluded that the current approach to Japanese knotweed was overly cautious.
Environet said its tool “allows for a much more nuanced approach, taking into account the size of the infestation and the distance to the nearest boundary”.
Ten per cent lower value
Environet founder and managing director Nic Seal said that in reality, affected properties were typically worth around 10 per cent less than an unaffected property, which reflected the cost of treatment plus the so-called knotweed stigma.
“JK-VIM offers RICS surveyors an easy to use online valuation tool to assist their own professional judgement based on the facts of the case and guides homeowners on how the value of their property can be preserved if the knotweed is professionally treated or removed,” he added.
Expert Surveyors director Paul Raine said: “The Select Committee was right to conclude that lending practices for properties affected by knotweed need urgent review.
“All that’s required to sell in such cases is a treatment plan and a sensible readjustment of the price.”
