Odd damp proofing system

During a Full Building Survey in Epsom, Surrey we discovered this Schrijver system installed on the subject property. This is a Dutch damp proofing system, however there appears to be no need for this to be on this property as there is already a dpc installed and there was no evidence of damp or historic damp. This system isn’t very common, however when seen, this system is usually installed into properties with 9″ solid masonry walls, not cavity walls as seen in the photo.