I think (rather I hope) they will be greener, built using more eco-friendly materials, and designed in such a way that minimizes energy consumption. I guess we will use solar panels and other alternative energy sources more than we are doing now.
I would love to have a cabin like house with kitchen, living room, and dining room all in the same room with no walls. The only walls I would have would be the ones around the bathroom and around the bedroom and I would only have walls that don't go to the ceilings around them so heating and cooling wouldn't be so much of a problem. I want windows that are shaded so it will be cooler and allow an air flow through the house. I've thought about this a lot and I think I would be happier and it would be simpler for us.