Usonian was derived from an abbreviation of United States of North America, and Frank Lloyd Wright adopted it for a distinctly American, democratic style of residential architecture he developed during the Great Depression. Intended as simpler, lower-cost alternatives to his highly customized houses, these homes were designed to be within reach of the average middle-class American family without sacrificing quality, and about 120 were built, beginning with the Jacobs House in 1936. Usually one story but sometimes modified for a client's needs with an upper story, they eliminated attics and basements to encourage simpler, less cluttered living. Open floor plans linked small kitchens, which Wright called workspaces, to large living areas, while large windows opened broad outdoor views and filled the interiors with natural light. Wright called the Usonian house a thing loving the ground with a new sense of space, light, and freedom. Much furniture was built in to save space and use leftover construction materials. Features now often considered green included radiant-heat flooring, large roof overhangs for shade, and clerestory windows for abundant daylight, all helping regulate utility costs and improve energy efficiency. A large overhang sheltered the family car in a feature Wright called a car port. These houses generally presented a blank facade to the street but opened to views at the back, making the most of the suburban lots for which they were designed, and were characterized by dominant horizontal lines, flat roofs with large overhangs, standardized natural materials, private open sides usually facing south, perforated wood clerestory windows, mahogany, concrete block, grid systems, inside-outside walls of matching materials or concrete block, French doors opening to nature, roofed overhangs integrated as car space, board and batten, a central hearth, built-in and modular furniture, concrete slab floors with radiant heat, integral decoration, elimination of unnecessary elements for efficiency, and warm wood tones with Cherokee red and soft golds predominating.