The RCD requirements for alterations to a circuit have changed with the release of Amendment No.2 (Amd 2) of AS/NZS 3000:2018.
Where clause 2.6.3.2.5 previously had an exception that permitted extensions to non-RCD protected circuits supplying lighting points without adding RCD protection, this exception has been removed in Amd 2.
In addition to this change, when adding socket-outlets to an existing circuit in domestic and residential installations, it is now a requirement to install the RCD at the origin of the final subcircuit.
Amd 2 under Repair clause 2.6.3.2.6 now includes the installation of an unswitched socket-outlet in a roof space at a height above 3m for the replacement of a lighting point to be installed, without RCD protection.