[2025] UKUT 053 (LC)

The key technical factors which need to be considered in determining a causal relationship between T1 and the subsidence damage are: the extent to which the subsoil was desiccated, which would indicate removal of moisture through the roots of vegetation, leading to subsidence; whether identified movement to the structures showed a seasonal and cyclical pattern, which would indicate cyclic root-induced shrinkage and recovery; whether the evidence of oak tree roots in BH1 was sufficient to indicate that T1, at a distance of 29.15m from the garage and 31.65m from the extension, would extract sufficient amounts of moisture to cause subsidence.

Determination of the causal relationship in this case was also influenced by other factors, which included: the discovery in June 2015 of leaking drainage in the vicinity of TPBH1, which the experts agreed led to high moisture content readings at depths of 0.9m and 1.5m; the close proximity to T1 of a second oak tree, T2, and the possibility that roots in BH1 were from that tree; the discovery of a land drain behind the garage when piling works were carried out in late 2018 – early 2019; the discovery at the same time that the footing to the left side of the garage was only 100mm deep. Obviously the last two factors were not known to the authority at the date of the third refusal.

In order to reduce, as much as possible, reiteration of the core material I will first review the evidence available to the authority, including commentary on elements agreed and not agreed by the parties and their experts. I will then review the submissions made by the respective counsel on how that evidence should be interpreted in the light of the expert evidence and cross-examination.

This initial report to the claimant was not relied on by either party and will therefore not be considered further.