I live in London in a 1940's type house.
I have incoming power cable that has 3 phases in my house, 1 powering my house with 1 going next door through party wall and 1 spare.
Over summer i had a call from my neighbour who rents his house out saying his leccy did a test which failed, says his house has no neutral, his leccy explained they will get the DNO out to have alook.
Thing is they had a loft conversion in 2006 and this did not crop up, cant remember the regs back then.
DNO (around 55 years old, younger DNO's wont know) says due to material shortages during war house builders had 1 cable serving 2 houses and neutral may not be connected properly. My neutral is connected to sheath of incoming main. I can see power cable going next door but no neutral, DNO pushes issue back to leccy saying thay have to install a MEP.
Neighbour in quandry, saying thay cant do this, they will have to connect onto earth on my side, i was reluctant but since his power is also coming form my side i allowed him to do it. On my side it took total time of 15mins to do the connection and he drilled a small hole poked cable through and fire sealed it, job done.
I had loft conversion done in 2016 and electrics passed, also had extension done in 2019, regs passed, presumably in order to pass the regs teh neutral would have also been tested as part of the EICR test.
... I did mention this to the engineer however he said "but this is what EVERYONE has [the looped supply] we're only required to provide a 60A service and that's what we've supplied"- (obviously also forgetting he had just told me that my supply was 30A
