This Thesis project presents an architectural-tectonic design proposal for the unexploited site of Place Mazas Square, 12th arrondissement, Paris. The New Place Mazas Square is the result of a project that aims to explore and investigate how to boost social sustainability and promote the resilience of the urban structure in a metropolis undergoing an ecological transition adaptable for the changes of the future. This by exploring a multiscale working method to fuse inherent site-specific potentials and to ensure a respectful approach towards the surrounding contextual conditions. The project is based on a desire to exploit existing energies of Paris to enhance new ecologies and synergies between functions and users. This resulted in the creation of a Neighbourhood Hub with habitation and shared functions, a Food Hub with a Bouillon restaurant and a greenhouse in great connection to an urban farm. This to enhance the community and create diversity through architecture programming that enables opportunities to attract awareness and change habits towards a better future. The New Place Mazas becomes a square with a strong collective identity to promote new modes of living, being and inhabit the city. A strong architectural-tectonic approach have been consistent through an integrated design process. Design solutions have been developed and evaluated due to functional, technical and aesthetical aspects in order to create a design with a solid architectural and tectonic intention, which in tandem enhance each other and create more than the sum of the parts.