Do double glazing even if your home reach 6 stars without it.
Especially for windows u want to leave not covered by blinds or curtain through out the night and…

As Renman has said the 3 meter option to downstairs is the best addition to the home. I know I did it and was worth it.
Hebel Powerfloor is also is…

My must do would be 3m high ceilings and my wish list would be hebel power floors.
In regards to solar, yes they do pre-wiring.