I quoted on a job where all the existing cables are in metal conduits, the sockets circuits have a separate earth but the lighting circuits do not. It was required that the DB board be upgraded (new breakers, e/leakage etc).

The readings for the socket circuits came back fine when I checked them, insulation resistance all good, earth continuity all sweet. We were to just replace the old sockets for new.

I quoted to run an additional earth wire in the metal conduits for the lights seeing as we were altering the circuit protective device and changing the light fittings. The other guy didn't - he argues that the circuit is existing and seeing as the light fittings are not part of a COC he can say the circuit was existing. The cables were not altered, just the protective device and the light fittings. The earth reading at the lights and the switches were good, well within limits.

I am just getting confused as what is considered existing these days....

I mean if you go to change a light switch and find that the earth is provided with metal conduit should an earth wire be pulled to every point even though the readings are good?

What do you guys do? walk away, change the switch and advise the customer, not touch it with a barge pole unless you can run that earth wire through to all the points.

This is why I stopped doing domestics, just a mine field of interpretations. I know I would like to run a new earth wire through the whole house but the client is not going to pay for that.