This modification of the spiral idea has four different levels per floor.  A gently sloped ramp around the outside, ziggurat style, solves the handicapped access problem.  And except for the garage and entry, the whole house is underground! Start from the upper left, where the garage is at level a (ground level).  From there you can either descend via the switchback ramp or walk through the entry pavilion and down a staircase to the core of the house, arriving in the country kitchen at level e.  Continuing counterclockwise, three more steps or another ramp bring you down to the dining room at level f, then to the upper half of the split living room at level g. (TEXT CONTINUED BELOW) Looking now at the diagram on the lower right, you can continue down to the lower half of the living room at level h, then the laundry and half-bath beneath the kitchen at level i, then the bedrooms. Looking at the diagram on the upper right, three steps down from the third bedroom at level l is another bath at level m.  Finally, there's a large basement rec room at level o, where the floor is 31 feet below ground level. This underground house gets some natural light from above.  Starting just to the left of the double entry doors, there's a long, narrow skylight that extends over the split in the living room to the central stairwell.  Also, the ramp spirals out as it descends:  each turn of the ramp is located a couple of feet farther from the center than is the ramp above it, so its outer half can be skylit from a light well (shaded in the drawing) that surrounds the main part of the building. Red "walls" on the plan are merely railings.  Windows in other walls let in additional light from the ramp.