Sea to Sky Invasive Species Council

The Royal Institution of Chartered Surveyors has launched a consultation into the effects of Japanese knotweed on properties in the UK and will produce an information paper for the industry.

The aim is to help valuers and mortgage lenders consider the implications of a Japanese Knotweed intrusion when undertaking valuations of residential property in the UK.

Japanese Knotweed is an invasive plant feared for its damaging effects when found on or near a property but these fears are often based on misunderstanding.

The plant became more of a problem when some lenders reviewed their policies and a number of loans on Japanese Knotweed affected properties were declined. This changed the status of Knotweed from a ‘difficult to solve’ problem to one that could result in property sales falling through.

It was reported recently about a couple in the UK who moved into a brand new house and have now been told it will have to be demolished because of knotweed which is growing through the foundations into the house.

RICS points out that although the plant can be difficult to control, with correct treatment, in many cases it needn't be a life sentence for a property. Since the mid 1970s challenges posed by building movement and asbestos have presented assessment problems that were largely resolved and assimilated into the lending process.

There is no reason why the assessment of Japanese Knotweed cannot follow a similar route and RICS is consulting on this in order to develop best practice guidelines. RICS is inviting responses from RICS members, lenders and Japanese Knotweed treatment experts by the 09 December 2011.

‘When assessing market value, valuers must take account of a variety of factors and the presence and effects of Japanese Knotweed is just one of the many considerations that may affect value,’ said Philip Santo, RICS spokesperson.

‘While this invasive, non native plant can be difficult to control it should be recognised that timely and persistent treatment programmes can minimise its impact. A standard risk assessment framework is being proposed to help valuers to provide more informed advice to their clients and to enable lenders to adopt more consistent and balanced policies,’ he explained.

‘As the treatment industry develops and matures it is hoped that Japanese Knotweed will soon become just one more consideration in the complex valuation process. The RICS consultation aims to canvass opinion in order to help make this happen,’ he added.