Villa Savoye succinctly summed up the five points of architecture that he had elucidated in "L'Esprit Nouveau" and the book "Vers une architecture", which he had been developing throughout the 1920s. First, Le Corbusier lifted the bulk of the structure off the ground, supporting it by "pilotis", reinforced concrete stilts. These "pilotis", in providing the structural support for the house, allowed him to elucidate his next two points: a free façade, meaning non-supporting walls that could be designed as the architect wished, and an open floor plan, meaning that the floor space was free to be configured into rooms without concern for supporting walls. The second floor of the Villa Savoye includes long strips of ribbon windows that allow unencumbered views of the large surrounding garden, and which constitute the fourth point of his system. The fifth point was the roof garden to compensate for the green area consumed by the building and replacing it on the roof. A ramp rising from ground level to the third-floor roof terrace allows for a promenade architecturale through the structure. The white tubular railing recalls the industrial "ocean-liner" aesthetic that Le Corbusier much admired.