This mixed-use development of 105 social housing units and 18 SOHOs (small offices/home offices), built on abandoned railyards at the edge of the center of Paris, is part of an innovative urban typology based on the differentiation between a “lower unified world” housing shops (SOHO) and “a diversified upper world” comprised of apartments. We chose to enhance this urban dialectic of the unity of the podium and the diversity of the towers by differentiating the expression of both volumes, even though they share common materials (concrete, wood, and aluminum) and common principles such as compactness or reversibility. The SOHO concept being a dwelling associated with a professional working space, we developed a specific typology close to the townhouse with dual public/private access ensuring continuity between offices and dwellings whilst also planning for separate entrances. This typological organization fosters indeterminacy between work areas and dwellings whilst also guaranteeing a modicum of intimacy between the different units. The fifth façade of the SOHOs, made of ribbed and perforated aluminum, looks as if it were extruded to form roofs with cutaways, or hollows to create areas for terraces and patios. The result is a morphology inspired by train sheds, echoing the site’s past history and optimizing the penetration of light. In the SOHOs, like the flats, architecture extends from the interior towards the exterior. Thus, it is not the framework of the façade that defines the openings but rather the views and the access to light that dictate the design of the envelopes and the size of the bays. Placed at the corners of the two volumes and benefiting from broad and far-reaching views of the Parisian cityscape, the living rooms are further extended by the kitchens and the bedrooms, thereby highlighting the great size of the flats along the broad glazed windows.