Since 1985, the Hôtel Salé has housed the Musée Picasso, but it had become too small to properly display the collections and no longer met current standards. Renovation work began in 2006, followed by a more extensive restructuring project launched in 2011. These works included the renovation of the outbuilding wing, which was transformed into the museum’s new entrance area, sheltered beneath a newly designed glass roof. This structure, the first visible element upon entering the museum, required particular attention both on its underside, visible from the ticketing area, and on its upper side, as it can be seen from the courtyard terraces and upper floors.

Although modest in size, the glass roof’s challenge lay in integrating a contemporary feature into a 17th-century hôtel particulier. Additionally, the chapel in the northern corner, which overhangs the reception area, had to be carefully considered from both a technical and architectural perspective.

T/E/S/S was responsible for designing the glass roof structure and envelope, subcontracted by the project’s architect.

Design Concept of the Glass Roof
The glass roof consists of two distinct layers, geometrically aligned, and bordered by a variable-width glazed strip. A PRS beam grid forms the primary framework supporting the opaque roof covering, ensuring weatherproofing, insulation, and maintenance access. On the upper face, this covering recreates the grid pattern and depth of the supporting structure.

The peripheral glazed strip allows natural light to enter the reception and ticketing area. Structural elements crossing this zone are designed to be as slim as possible, emphasizing the contrast between the transparent periphery and the opaque central section.

Structural System and Integration with the Chapel
The primary glass roof framework is housed within a rectangular volume positioned directly beneath the overhanging chapel. It consists of four main PRS beams, spanning from wall to wall, supporting secondary transverse beams, which extend about 1 meter in cantilever beyond the primary beams. Together, these primary and secondary beams form a grid structure, which is mirrored on the upper surface of the glass roof.

The opaque roof covering extends over the metal framework, except beneath the chapel, where only the structural beams continue, leaving the underside exposed. Above the roof assembly, recessed panels recreate the geometry of the visible metal framework, ensuring continuity between the lower and upper surfaces of the glass roof.

At the junction between the opaque and glazed areas, variable-width glass bands introduce natural lighting into the reception area.

Although T/E/S/S joined the project team at a late stage, their mission covered both the technical development of the glass roof and the architectural concept refinement.