Considered one of the more innovative designs of the program, Case Study House #4 was referred to as the “Greenbelt house” by architect Ralph Rapson. Though the house was never built, detailed plans reveal an unconventional approach featuring an interior garden or “greenbelt” running directly between the communal areas of the home and the more private bedroom areas. These three bands come together to form a rectangular area under a sloping butterfly roof. A modular wood and metal repetitive framework accommodates large panels of glass and plywood, further emphasizing the unity between inside and out. Rapson’s drawings also specify modern furnishings, a jeep in the carport and a futuristic commuter helicopter flying overhead.