On Lyon’s Boulevard des États-Unis, four compact clay buildings form a unified ensemble atop a shared base that separates them from the street. The auditorium opens onto a public square and is built as a timber structure with glass infill panels enclosing two massive clay cores. A vertical opening connects the cores visually and symbolically, creating a light-filled zone for gathering and exchange. Clay, long used in Lyon for its thermal and acoustic qualities, is combined with straw to enhance insulation. A geothermal system circulates energy through embedded pipes, using the material’s natural storage capacity. The façade’s fine rhythm translates the building’s scale into human proportion, merging craft, sustainability, and civic presence.