I think the most important points are the roof garden and the horizontal and huge windows in his idea. In classical architecture, the buildings are always pinnacle and having some ornamentation at the top of the architecture like the reliefs. But Corbusier changes these idea into a garden, which is a perfect idea of using the surplus of the areas at the top, and a good start of the combination of the buildings and the environment. Also the huge and horizontal windows make the buildings more transparent with a better daylighting.