Le Corbusier and Pierre Jeannert wrote the short manifesto "Five Points Towards a New Architecture" in 1926. The five points they discuss are supports, roof gardens, free design of the ground plan, horizontal windows and free design of the facade.
Le Corbusier and Jeanneret do not go into detail about why the five elements are important, or how they relate to architectural theory. However, they do state that the principles are facts that underlie a new approach to building design. One of the architects' most famous projects, the Villa Savoye, exhibits many of the five points, including a roof garden and horizontal windows.