Planning a layout

To maximize efficiency we need to build our house around the technologies we are using. I have started to search for a design that will fit but it seems difficult. I think we might have to design the layout ourself. I am thinking of a design where the main heat source is in the middle of the house. Living room, dining, and kitchen will be open plan. The front door needs to be shielded to keep the cold air out of the house, so a small hall with a door is needed. A fuel store would be handy and a little walk in closet for shoes and coats. We will need 4 bedrooms, an office area, a toilet/shower room and a main bathroom. Ideally we would have a guest room as well.
There are two options for the design, either a traditional one where the living space is downstairs and the bedrooms are upstairs or we keep the bedrooms downstairs of the corner of the house and just have a bathroom, office and guest room upstairs, or maybe a play room.