How can architecture studios organize themselves to design according to the 17 Global Goals for sustainable development? How should these topics be declined in architecture and design projects and what effectiveness can they have to build a better world? These are the basic questions around which the survey of the supplement EcoWorld 2019, elaborated with the advice of Arup Italia, is structured. The supplement to Domus of September offers a photograph of the current situation of design practice through this key of interpretation and indicates possible areas of intervention, to respond pragmatically to the ‘objectives’ defined by the great world powers in 2015, evolution of those Millennium Development Goals signed in 2000 that were focused in particular on the theme of poverty and the needs of developing countries. Agenda 2030 has a broader scope than its predecessor. Its 17 points touch closely the world of design, even if the difficulty of defining the language of sustainability, which is constantly evolving, makes it difficult to translate them into project practice. EcoWorld starts from four essays exploring the themes of the city and complex systems, with a report of excellent cases by Piero Pelizzaro – chief resilience officer of the City of Milan – and a pungent and punctual dysanimity on the real power of architecture to “save the world” by Richard Ingersoll – which indicates in a well-organized urban planning the most effective weapon to provide concrete responses to climate change. Paolo Cresci and Jo Da Silva move in the field of construction practice and indicate the fundamental principles to design for man and nature, voices to which are added those of four international professionals – Neven Sidor of Grimshaw, Anne Lacaton, Natalie Mossin and Anna Heringer – interviewed by Domus. But the largest part of this publication is reserved to architecture and design projects selected from around the world. We went to Lausanne, where 3XN has just inaugurated the new headquarters of the International Olympic Committee, which has obtained the highest levels of certification from three of the most demanding environmental assessment bureaus. In Ho Chi Minh City, on the other hand, Vietnamese firm VTN Architects has built a tropical house in a new residential area of the city, the latest in a series of “tree houses”. In Mexico, in response to the 2017 earthquake, PienZa Sostenible created a virtuous network of local communities and architects, while in Denmark Effekt Architects worked on sustainability with a tower in the forest and on social change with a housing module designed with Space 10 by Ikea. Water is the main ‘concern’ of the design projects that we have pointed out: the toilet of the future born from the research of the Gates Foundation and realized thanks to Eoos and the sterilization system engineered by the Swiss GratzUp and ‘translated’ into water bottle and can by Giulio Iacchetti.