property has no earth bond on the gas pipe so need to add a main earth bond for the gas pipe,its an external meter in one of them brown boxes and the gas pipe runs round the front of the house braches off into the front room then carrys on round the house another 8m and brancehs off into the utility room for the boiler then carrys off round the side of the house into the kitchen total run of about 25m externally.now regs say to bond 600mm at point of entry into the building,but which bloody one? consumer unit and electric meter are both outside the house on the far side, opposite side of the house to the gas meter.last gas run is right next to consumer unit.any help welcome