Dealing with informality means dealing with spatial and morphological situations, with conditions and dynamics that are di?erent from the ones existing in a "top-down" designed area. The informal is a wide multifaceted chapter engaging a great variety of ?elds. As an architecture scholar, I expanded my research ?rstly at urban level, then at the architectural, ecological and energy level. I also considered necessary to frame the issue from the socio-statistical, historic and referential point of view, through a general outline of the situation. Studying and interve-ning in the existing relations of a "bottom up" dimension show a dynamic process, an ever-changing endogenous mechanism. To deal with informality does not mean to work in the absence of regulations, rather it means to keep facing standards di?erent to the ones of formal cities, which represent examples of our Euro-pean culture. The word "weak", should not be understood as fragility, rather as lightness, ˛.exibility, as an agent likely to adjust to changes, but still capable to stay solid and connected in its own structure. 0-nCollection of Master Thesis of Politecnico di Milano within the Theory of WeaknessDirector and Coordinator: Elisa C. Cattaneo "0-n" is a collection of master thesis which I oversaw as supervisor at Politecnico di Milano. These books are a platform of heterogeneity, which ?nd their common ?eld in the theory of weakness, as imperfect and manifold way of knowledge. The aim is to experience an alternative method for contemporary spaces, able to regenerate the stabilized ideas of design. They are more experimental and vital texts/tests than veri?cation procedures: this attitude brings them away from a strictly educational approach. They can be read according to two levels of meaning: in their speci?c contexts and as open platforms for contemporary researches. Almost all of them are focused on processual values and on project transdisciplinary, in order to promote a cognitive space before a real one. I provided the students with fews thematic lines (a sense of short-circuit, trial, process of meaning), which were underlining an interpretation of knowledge in a horizontal sense, as Gilles Deleuze had de?ned.These topics have been independently developed by the candidates, so that they can be considered as authors of a new idea. I instructed this learning and researching method, because I belive that the secret of an e?ective education in to coinvince each student to be able to build his own vision of the world, without stereotyped positions.I am ?nalising the object of education in the freedom of intelligence, and not in the rules of disciplines, by broading the students' needs and points of view. To cross the world in new expanded geographical horizons.