Now since the plan shows an octaganal room we need to add more foundation before we do this turn CFE back on
then use the diagonal foundation tool to remove sections of foundation
create walls inside foundation like the folowing pic
create a wall to the side of the house as a leveling aid and turn CFE back on
level the entire house
turn CFE cheat back off
then use straight and diagonal foundation tools to remove foundation as follows
add walls and a stair
use MOO cheat to place windows in foundation and upperwalls
you will have to play with the windows to find the ones that work best....
but at the end you have a house very close to the floorplan look
you can also just do regular walls raise terrain as close to the walls as you can go and use MOO and flowers to hide the slope nearest to the walls.