摘要：Shape grammar has been used by many researchers to identify and/or define languages in architectural design. This paper presents a methodology developed using shape grammar to analyze the informal city, specifically Favela da Rocinha’s buildings, in Rio de Janeiro. The goal was finding the organizational foundations of self-built houses in an informal settlement. A methodology was developed to find composition patterns and to infer a set of rules which defines a shape grammar of Rocinha houses, allowing synthesis and analysis of low cost solutions for house designs. And above all, it highlights underlying design solutions produced empirically by inhabitants of favelas, emphasizing the diversity in favela’s architecture, and, that is also able to reflect the particular necessities of targeted population.