great passive solar design- I would plant row of deciduous trees in front of glass so that in the winter that could act as a giant trombe wall but be shaded to keep it cool in the summer. Trees that max out at 2 stories would allow south face 3rd level roof to accommodate panels!
A Trombe wall is a passive solar building technique where a wall is built on the winter sun side of a building with a glass external layer and a high heat capacity internal layer separated by a layer of air. Heat in close to UV spectrum passes through the glass almost unhindered then is absorbed by the wall that then re-radiates in the far infrared spectrum which does not pass back through the glass easily, hence heating the inside of the building.
Good, clear presentation of Seasonal Window Considerations for Passive Solar homes. Windows must be climate sensitive: check to see if they show be double or triple paned, or even covered with a thermal shade in coldest climates.