[2023] UKUT 214 (LC)

It is accepted practice that compensation under the Act for loss of value arising from physical factors should be assessed by comparing, at the valuation date, the market value of the claim property subject to the physical factors, known as the “switched on” value, with its hypothetical market value assuming those factors were “switched off”. The important point is that it is only loss of value arising from any of the specified physical factors caused by use of the works that can be compensated. Loss of value arising from any other aspect of the works which could affect the market for the property, such as loss of view or outlook, loss of amenity or convenience, cannot be compensated.

Valuation evidence is therefore required to establish the switched on or actual value of the property at 1 September 2021, and also a hypothetical value at that date with the physical factors switched off, but all other circumstances of the new development in place.