The City, understood as a support for human activity, may account for up to 60% of greenhouse effect emission gases. Traffic, construction, heating, and the distribution of commodities and food are some of the activities that make our cities huge energy drains and largely responsible for the environmental problems we face. We also believe however, like Jaime Lerner, that the City is also the Solution. The challenge is how to transform our cities and redefine the city – citizen relationship. The challenge is to reflect on the way that we can reorganise our urban environment and how we can adapt it to a new age. It is making progress in Materials and Technology and in the way to use them. It is reflecting on both horizontal and vertical building models, their consequences, and their point of balance. It is above all understanding that our work influences the whole planet, and assuming this commitment. We open this debate to architects, engineers, and professionals at an international level, and invite you to share knowledge and to imagine a new way of inhabiting, thinking about, and designing our cities.