If the Electrical Installation Condition Report (EICR) is Satisfactory then you do not need to replace the consumer unit, even if it does not have RCD protection
Answered by Sarah, Electrical Safety Expert
If the Electrical Installation Condition Report (EICR) is Satisfactory then you do not need to replace the consumer unit, even if it does not have RCD protection. RCDs are only required by law in new builds, additions/alterations or rewires.
If you don’t want to replace the consumer unit, Electrical Safety First advises using plug-in RCDs or installating RCD-protected sockets, particularly for anything you are using outdoors, for example the socket you would use for your garden mower.