Considering the requirements around only doing like for like this series looks promising. A Wifi control unot to go in the switchboard requires a sparky but once thats done working through powerpoints and light switches over time is easy enough. Not cheap of course. I've seen plenty of replacement light switches that appeal but this range includes powerpoints and avoids the need for smartplugs always on (or shelly relays in the wall). Netatmo based so can integrate with home assistant.
https://www.legrand.co.nz/products/automation-systems/excel-life-smart
Thoughts?


