The Hemiciclo Solar is located in the city of Móstoles, a few kilometres from Madrid. César Ruiz-Larrea is the architect of the project. The building is the result of a restricted competition, and it includes 92 dwellings to be rented out to young people. The Hemiciclo Solar plan has the shape of a circumference sector. The front of the building faces south, so as to receive the best sunlight in all the dwellings. The corridors runs along the north side, and there are also three common areas open to the air, and to the city. The north and the lateral façades, almost hermetic, are resolved with large panels of multi-colored polycarbonate (the architect has given a lot of attention to the colors). In contrast, the south façade is very permeable, which is achieved through mobile slats that control the sunlight and filter the light. The project strives for bioclimatic efficiency, seeking sustainable solutions.