Thanks for your interest, it was a shop, flat above, converted to two flats, about 11 years ago, two new Consumer units (just discovered no RCD) and mostly new wiring to make each flat
independent, and appropriate for flats rather than shops. i have had two electricians look, one wasn't interested, the other said he wouldn't even bother to test it without RCD . he said the landlord test was called EICR and it would fail without RCD. But my question really related to ; do you think the builder should have included an RCD 11 years ago? i want the tenants to be safe so i will have to get them retrospectively fitted , and ideas what i should be charged please?