We are having our conservatory replaced with a more substantial "garden room". The electricity in the conservatory was a spur off a current ring main, and the new room will be the same. The electrician says we must have the current consumer unit (which is plastic and has no RCDs being ~30 years old) replaced in order for the work to be certified. We had the system checked a few years ago and although advised a new consumer unit would be better, told it was not a legal requirement.

So do regulation require a new consumer unit with RCDs for this ring spur to be re-added, or is he being over cautious?