Hi Guinnessimo,
I have a strong concern for these energy saving questions. If I had the time... I would investigate the question of the "intelligent" house too. I feel a little sorry not to disclose my works so far.
About the Ethernet connection: As you know, France is part of the "old continent" and most houses are not fitted with networks or what so ever... Mine was built... 2 siecles ago! Thus my concern for wireless...