Given the increase in claims of Japanese knotweed (knotweed) encroachment and commercial investors, especially institution investors, are deterred from purchasing properties affected by knotweed, it is prudent for property portfolio holders to understand the risk presented by non-native invasive species (INNS). Richard Newis of AJK has undertaken pre-acquisition due diligence reporting on behalf of some of the UK’s largest property portfolio holders and reviewed the risk to existing assets, from single sites, through to significant property portfolios such as Translink and Ulster Bus in Northern Ireland.We recently undertook a desk study on 26 properties, on behalf of a Housing Association, and identified 9 of the 26 properties should be surveyed for knotweed. This is a relatively high percentage for a property portfolio, as typically we see a range of 4% to 7% of properties requiring further investigation. On surveying the site we will identify which properties are impacted and of those properties which are encroaching onto third party land; where encroachment is from third party land; and where encroachment would be difficult to prove both for the client and third party landowner. Given that AJK is seeing claims of between £40k and £80k for cases of encroachment, should 9 of the client’s properties be impacted by knotweed and it can be demonstrated by neighbours (potentially three claims per property impacted) that encroachment is from the client’s land, the potential cumulative damages are significant, potentially business ending. If you manage a property portfolio and want to discuss our services further please feel free to give Richard a call.