A play of solids and voids for the INSA Strasbourg architecture school, a breakthrough in Technal aluminum solutions

The result of a collaboration between the COSA and RHB ARCHITECTES agencies, this project is part of the overall restructuring of INSA. It intelligently exploits the original plan of the building, designed in 1960, to adjust its connections, which had been disrupted over the course of the extensions. It also allows for the reorganization of the various departments to embody INSA's specific pedagogy, including the relocation of the architecture training program to a new building.

EVOLUGLASS, a manufacturer and installer of TECHNAL joinery, worked on this construction. It installed more than 200 m² of TECHNAL facades, and 2 m² of SOLEAL sliding, fixed, and snap-in frames. All these solutions are made of Hydro CIRCAL 2.000R, an eco-designed material made from at least 2% recycled aluminum from post-consumer waste. Their anodized finish gives a precious effect to the envelope. It accentuates the shine, like a mirror that plays with the reflections of the cladding and the wooden structure. The architecture school integrates into the existing buildings by adopting identical structural rhythms and the same objectives: to be architectures of use, refined, regular, luminous, fading away in favor of inter-user and inter-departmental relationships, and adapting to pedagogies. It rises over 75 levels and houses teaching rooms, administrative offices and 75 multipurpose and spacious workshops with double ceiling heights for making prototypes.

Maximum transparency

The architects and the EVOLUGLASS company worked together to meet a dimensional challenge: finding the optimal compromise between thinness (32 mm) and rigidity of the profiles, all within a height of 2,70 m and a frame of 4,50 m (double leaf). A technical and aesthetic feat! The discreet visible masses of these XXL openings in TECHNAL continuous strips, combined with the large spans without posts, offer wide views and total transparency. Beyond the contribution of natural light to the interior, it is the relationship with the outside that has evolved. Students and teachers benefit from a real spatial quality with workshops that extend to the exterior. The comfort of study and life is maximized.

A prefabricated wooden structure is erected around the INSA's concrete core. The primary beams (36 x 2,72 m and 18 x 2,72 m) are skillfully stacked, like a Kapla® game. Their arrangement creates one or two rows of bay windows in each workshop. The low sliding windows, which open the school to the city, alternate with the high windows that create display spaces. Above, secondary beams appear to float in the void of the joinery, prompting students to question their implementation.

Choose each material for the right reason

For Benjamin Colboc, architect of the COSA agency: "Responding to the constantly evolving pedagogy and our ecological convictions, INSA Strasbourg is condensed into a structural and regulatory framework, into which the program elements fit, interchangeable and adaptable over time. This approach combines low-tech, frugality, logic—whatever name we give it. It also reveals the quality of the materials."

For this new building, COSA and RHB architects sought greater savings in materials for greater uses, versatility, simplicity, and common sense. This approach is evident in the building's very structure, with its overlapping wooden beams naturally distinguishing spaces, but also in the choice of finishing work limited to the bare minimum.

The visible masses of the profiles, for example, are reduced to a minimum. They contribute to the optimization of the material, as does the repetitiveness of the grid which allows for rationalization of aluminum and costs. In the same logic of controlling the impact of the building, the fluids are left visible to be easily modulated and avoid the installation of a false ceiling, the walls that are made of concrete or wood do not need to be lined or painted...

The frugality of the design is matched by the variety of possible uses in each workshop: working alone or in a group at a table, making a collective correction along the display panels, setting up for a drawing class in the living room, attending a lecture with video projection... The sustainability of the project is also expressed outside. The compactness of the plan has allowed the development of a new experimental area: the prototype garden. The courtyards are renatured, to make this space an island of freshness, a green lung where students can work outside, expressing their creativity while enjoying a green landscape.