One way of bringing greater clarity to the allocation of risk in respect of subsurface conditions is to use geotechnical baseline reports (“GBRs”) to allocate this. Whilst GBRs have been commonly used in major underground works projects around the world, the risk of subsurface conditions is more typically dealt with by general concepts such as “unforeseeability”; what an experienced Contractor should have foreseen at tender stage. Without a more objective measure setting the parameters for what is or is not foreseeable (e.g. by reference to limits within a GBR), this leaves the matter open for interpretation and debate and in turn creates uncertainty. This has led to a number of court and arbitral decisions in which Contractors have been found to assume the risk for subsurface conditions outside the limits of certain geotechnical surveys provided at tender stage notwithstanding that in practice Contractors often price the risk of subsurface conditions based on these very limits.7