The increases in both the elderly population and urbanization present new problems for planning new cities and managing old cities. To solve this challenge, innovative ideas/proposals that encourage walkability and reduce fossil energy motor transport are needed, in line with the actions advocated by Sustainable Development Goal #11 (SDG11), Sustainable Cities and Communities. Opening passages that cross blocks, creating connections between the streets, is the proposal discussed in this paper, as seen in cities like Paris, Prague, Milan, and Juíz de Fora, which have passages in their urban fabric. These can be implemented in a building’s rehabilitation or when a new building replaces it. New architectural project designs should have several characteristics that promote walkability in the city, including passages and galleries. Although previous research has obtained promising results, extending the research to different urban fabrics and block sizes is needed. Using space syntax and data analysis, we simulated and quantitatively assessed the walkability of three neighborhoods in Lisbon, Portugal. The comparison of all simulations and the discussion of the results show that the passages improve walkability. It is also noticeable that there is higher walkability in orthogonal urban fabrics than in non-orthogonal fabrics. The results for block size are inconclusive.