What is Iwan

The topic of this chapter is the geometry and the construction of vaulted and decorative systems called ‘muqarnas', one of the most typical elements of Islamic architecture. This way of ‘vaulting spaces' or building roof and decorations with a system of regular staircase-elements that break down the surface covering it with simple geometrical figures, so as to make up complex patterns, spreads throughout Arabic countries, leading to the development of several styles, deriving from different generative geometries, and from building techniques and used materials. The reason which accounts for the widespread development of this type of decoration is to be found in the prohibition of the Moslem religion to portray idols or anthropomorphic figures of God, in contrast with the decorative techniques of sculpture and painting characterizing Christian art. The geometrical study which is at the basis of the Islamic art of decorating is arousing new interest and attention as regards the new systems of parametric modeling in computer art, besides opening new perspectives in standardized building techniques with new materials.