The Armco-Ferro House, designed by Robert Smith, Jr., of Cleveland, Ohio, embodied porcelain enamel and steel in the form of a prefabricated home. It was the only remaining Century of Progress home that met the Exposition Design Committee's criteria that it could be mass-produced and was affordable for an American family of modest means. Manufactured for $4,500 by Insulated Steel, Inc., for the American Rolling Mill Company and the Ferro Enamel Corporation, it was the first house produced using frameless steel construction and an exterior sheathing of vitreous enamel. Bob Weaver, Ferro's president, originated the idea of using porcelain and enamel for residential construction. The 2,400 square-foot structure was erected from prefabricated panels in only five days. Its revolutionary frameless system used corrugated steel panels no thicker than a dime connected by steel clips, and this construction later inspired post-World War II prefabricated housing for returning GI's developed by the Lustron Corporation. Although its shiny porcelain-coated metal exterior made it look somewhat like a cardboard box and likely startled fair visitors accustomed to traditional bungalows and Victorian-era wood frame houses, its interior was comfortable, finished with plasterboard and modern furniture, and arranged in a familiar way. Much like the popular four-square houses of the time, it had four bedrooms and two bathrooms upstairs, with a living room, kitchen, den, and dining room downstairs. This combination of a modern exterior and a traditional interior set it apart from some other Century of Progress homes, which pushed modern design and finishes both outside and inside.