Architecture is an art, an art of time which has to link beauty, fonctionnality and durability following the evolution and the will of the human being.
Durability is a main thing in architecture.
If the material is not architecture, it is his skin, his visible part whereby it get older. How reacts a building in view of time ? Can we see marks of the time like on a piece of copper?
Indeed, the corrosion means that we are aware of the influence of the nature in the material evolution. We maybe have a too idealized vision of architecture as an industrial object with a clean, smooth and fresh surface. But time goes on the material as it happens in our lives. Like us, it has to be maintained, it breathes, it crumbles leading to inevitable mold and dust because of external forces like wind, light, water and so on which removes to architecture a kind of transcendence. The material has a living aspect and architecture is involved in a natural movement, where the material changes over time. Then, the architecture is no longer considered as a form but as an alive object.