Yes, the presence of Japanese Knotweed can potentially prevent a mortgage being secured on a property, though this will depend on a number of factors such as the size and location of the infestation in relation to the property, whether the infestation is within the property boundary or on adjacent land and the company standpoint of each individual lender or mortgage company.
Ways to increase the likelihood of securing a mortgage would include – Having a site inspection and obtaining a written report from an accredited contractor to confirm the presence, location and potential extent of any knotweed present to include a breakdown of the proposed treatment, timescale of works programme, written confirmation of guarantees and warranties provided and insurances as required.