The development of architectural culture in the world, inspired by optimization criteria between built volumes and open spaces, places at its core natural lighting and radiation. However, it is not always possible to cater to natural light in the same way to all the interiors: this is what makes up the innovative and unique CoeLux® system. It replicates - in small perimeters, fractals situations and to large cubic totally devoid of light or not sufficiently lit - sunlight in favour of a lasting, substantial and profitable exploitation of buildings in every part of their inner surface.