ELEMENTAL (Alejandro Aravena, Gonzalo Arteaga, Juan Cerda, Victor Oddó, Diego Torres) is a Do Tank founded in 2001, focusing on projects of public interest and social impact, including housing, public space, infrastructure and transportation. A hallmark of the firm is a participatory design process in which the architects work closely with the public and end users. ELEMENTAL has built work in Chile, The United States, Mexico and Switzerland. After the 2010 earthquake and tsunami that hit Chile, ELEMENTAL was called to work on the reconstruction of the city of Constitución, where we had to integrate all the previous experiences. The approach we developed proved to be useful for other cases where city design was used to solve social and political conflicts. At the moment, we keep on expanding into new fields of action.