One of the most elusive construction material is light. It comes as a given but it creates the most incredible thing named shadow. Light was there at the beginning and with it came shadow movement and timing. Our lives are regulated by the variation of the light that surround us. In a building the shadows or the pools of light are essential elements of our creation. Given the climate dry or humid, the shadows might be perceived differently. In certain climate a shadow on a pink wall turns violet, or green on a yellow wall. Our ancestors the Greeks did make it a regulating factor of their architecture, planes were only created to greet a beautiful shadow that could reinforce the image of a building. Sun is a building material and shadows are motion associated to it.