They are offices for a building company of public works located in Manresa. They only receive light through the four windows which look out onto a central and nice avenue. The main offices are located next to the avenue and can be communicated in a controlled way. The challenge was how to lead the light to the furthest points from the street but keeping the privacy of the management's offices. Strategies whose aim is to suggest public works' material, infrastructure, landscape and road signs, suggest the choice of the materials rejecting the comparison and the triviality. A set of solutions in the service of the smoothness, the transformability and the permeability to the light, have their maximum exponent on a crushed stone wall, which is the basic material used for public works.