A glass canopy for the University Library in Rennes

Retaining the spirit of the site while improving its energy efficiency

The renovation of the former university library in Rennes gave Egis the opportunity to show its full range of expertise: structural and façade engineering and environmental efficiency were all required.

Date : 2012 (delivery)
Contractor: Rector of Rennes
Architect: Bruno Gaudin, mandataire and Benoît Gautier

Project overview

To modernise an existing building and make it more efficient, while maintaining its "genius loci", the studies led to the design of a cover for the courtyard in the form of a glass dome. The geometry of this solution creates dialogue between architectural work and structural and energy efficiency.

To bridge the gap between the four sides of the courtyard (21x28m), Egis designed a gridshell, whose shape is that of a double curvature cushion. The structural elements are set out in diagonals and form a uniform rhomboidal mesh. The shape of the roof is based on the use of translation surfaces, so as to construct the dome using flat quadrangular windows.

The patio cover also involves bioclimatic aspects.

Installing a "lid" over the building renders it more compact, and its energy consumption is reduced as a result. By adding sun breakers, combined with coated double glazing, the surface meets comfort requirements for both winter and summer.

Acoustic comfort is achieved by alternating opaque panels and glass modules in the cover.

Our missions

Design of the glass canopy and comfort simulations.

For the renovation of existing buildings (10,000 sqm) and the construction of the extension (500 sqm), Egis also provided general engineering, diagnostics, construction management, planning and fire safety tasks and environmental engineering.

© BRS (mandataire), Behnisch Architekten