ALU is a Flexible unit thought as a working and living open space. Is not just an architectural object, but an instrument of a more radical urban strategy that wants to reach an higher mixed use of blocks for a more sustainable urban culture. ALU creates a new urban life adding strong identity elements and green densification on roof of lower buildings and pavilions in the center and first outskirt of the city. The inner zone is adaptable and enlargeble by adding new modules or creating new internal separations. The multifuntional light structure with double skin allows to keep the inside space flexible and collects all the water and electrical systems. The creating process is based on recycle materials and energies. The rainwater is gather and it is heated by a low-tech roof circuit which takes advantage of the solar radiation. This system meets the requirements of hot water and heating system. Wind provides electricity from the integrated Windbelt low-tech system.