Hi aesmith, yes, my main concern is with the safety of the earthing. I was originally concerned that the system was TT or similar, and so the CU required a 100mA RCD. At present it has no RCDs at all. As someone else said, the earthing arrangement that I do have here could deteriorate underground. Similarly with the outbuildings, I wondered if earthing rods were required and am still unclear on that one, because some folk say you can never have too much earthing. If he system here is TN-S, then I should worry less. SSE is installing a new substation couple of miles away from here right now, so I will ask again for someone more technical to visit. Thank you for your help.