Usonian houses were always one story, with no basements or attics. The interior rooms formed a linear arrangement, with the fireplace and the kitchen near the center. Perched on top of a hill, Frank Lloyd Wright's Kalil house appears to be larger than it really is.
Frank Lloyd Wright called homes like this "automatic" because they used preformed concrete blocks that buyers could assemble themselves. The blocks were usually 16 inches wide and 3 inches thick. They could be placed in a variety of configurations and secured using a "knit block" system of steel rods and grout.
The floor was made of concrete slabs, typically in a grid of four-foot squares. Pipes carrying heated water ran beneath the floor and provided radiant heat.