Thanks everyone, it was helpful to hear different views. Finally I found a good electrician. I will replace consumer unit and go with current regulations.
Special thanks goes to Binky :) , very useful
what is ESL?
I have TT, and electricity provider put PME near to consumer unit, but didn't connect to consumer unit, as electrician needs to check if it's ok to do that.
Extractor fan in bathroom, which is on extension in terraced house. Bathroom has a bulb inside with switch outside bathroom. I need extractor fan which goes on with light, timer delayed.
Consumer unit has 5 MCBs (30,30,15,5,5) and 100mA RCD.
I needed 2 tasks: earthing on TT system, and installation of extractor fan. RCD is 100mA
One electrician says he can't do job, until I get consumer unit upgrade and all tests etc.
Other electrician says, it's ok to do job on existing consumer unit.
How to know which one to believe?