Forming part of the development of the Palais Montcalm becomes the major cultural space, revealing a novel public space; the courtyard. In continuity with the existing building, a tripartite composition orders the ensemble of new volumes giving onto the western courtyard, whose integration is accomplished by a superimposition of layered planes and by interlocking volumes crowned with roof gardens.

The principal intervention in elevation consists of the installation of a large glass plane with variable transparencies that performs a signaling function and reinforces the location of the concert hall on the large plaza.