if the ceiling has to be lower in spots, The heated square footage doesn't count if under a certain height. See about utilizing those space for storage, bookcases etc...to make the space attractive and purposeful
VarexHuis, Wonen met stijl - Eigenhuisbouwen.nl
This just gives me the idea of how nice it would be to have some sort of way to store each family member's laundry. Nothing else about it is too appealing. But this is a pretty compact way to do something like that.
Build a second mini-fridge in your kitchen island for BEER. | 31 Insanely Clever Remodeling Ideas For Your New Home