Here we aim to exemplify the careful use of materials with which HArquitectes resolve their architecture, and therefore their façades. On this occasion, only two materials are used: thermal insulation and perforated brick (gero). In the inner wall, the structural support, the brick is arranged in such a way as to withstand the loads transmitted by the slab. In the outer wall, the same brick is rotated to show its perforated surface, which ventilates the cavity between the two walls.