The urban mobility infrastructure axes have an important potential in the structuring and aggregation of the urban fabric. Throughout the last century this fact takes on special relevance due to the increasing fragmentation of the fabric and its processes of composition. It is through the main infrastructural axes that the relations of continuity, physical and spatial, are often preserved occurring in certain cases a distortion of the notions of space and time. Thus, the strategic (and spatial) value of these urban elements causes, in the contemporary city, the definition of new linear centralities that attract buildings and singular uses. Marginal occupation often occurs in a fragmented and individual way. Infrastructure and urban fabric are thought out, and constructed, separately, creating often weak morphological relationships or indirect systems. Despite this, it is evident the creation of symbiotic mechanisms of interrelation between the infrastructural axis and the surrounding built fabric. Its formal caracteristics are influenciated by the visibility allowed by the infrasctrutural axis. A more or less constant continuum is built, but the vision as a whole appears relatively inconsistent, not stabilized and poorly articulated with the adjacent urban context. The formal composition of the building itself has contradictory characteristics, on one hand it establishes strong visual and functional bonds with the infrastructural axis, but on other hand, its form as an architectural object, does not always contribute to a qualification of the space as a whole. The article seeks to look in a particular way for the case of the Start-Up Buildings, singular buildings that by their morphological and functional characteristics are promoters of particular dynamics capable of reinventing the urban space around them. There is particular interest in its ability to generate ambiguous urban spaces, developers of crossings and connections between distinct parts of the city, as well as links between the built fabric and the mobility infrastructure that supports it. In this way, through the study of these Start-Up Buildings is intended to collect contributions that can inform the exercise of the project, using them as didactic objects and not as models. It seeks to systematize principles of composition that allow a better articulation between certain infrastructural axes and the singular buildings that surround them, such as for example shopping centres or megastores. The qualification of the public space and the relation that it constructs with the collective space is seen as a factor that would potentiate the capacity to connect the two elements: infrastructure and building.