This style of house is also referred to as a split ranch. The bi-level house is a modified version of the ranch house, with the major difference being that the lower level is more out of the ground than in the ground. Seldom is there a basement.
Entry is often to the center of the house, with the foyer being split between the lower and upper levels. The lower area will frequently consist of a built-in garage and a storage area. Many bi-levels are featured in housing developments completed during the 50s.