re: Some questions reguarding building a home

Can't answer your question in terms of construction cost but I wanted to comment on its HVAC expense.

I agree it looks pretty and makes a smaller room look huge, but from experience I'd advise you to consider your a/c expense before deciding to go this route. Our HVAC has to run a lot longer in the summers to keep the temp correct than if it were a regular 10' ceiling height room.