Public rental housing is not just a care service to rescue the base of the social pyramid. It is also a predistributive element, as fundamental as health or education, which benefits the society as a whole. Public housing not only links the social fabric but can also serve to reconnect the urban one. Like public space, housing can be an instrument of urban improvement. In fact, through residential policies, cities can be transformed into a more mixed and compact environment, that is, fairer and more sensible. Cities made up of neighborhoods with small plots, with corridor streets that favor the commerce of proximity, the mix of uses and social classes, the movement of pedestrians and cyclists and the possibility of an efficient public transport. Far from being nostalgic, this model is very pertinent today to face the economic, ecological and political challenges that we are confronting.
During the twentieth century, modern urbanism has not only been unable to produce this compactness and mixture, but also has mistreated the urban fabrics inherited from the past. But, the mixed and compact fabrics are the only ones able to create centrality and that is why they are the most valued by the tourism industry or the real estate market. It takes a change of urban paradigm that democratizes the possibility of living in a compact neighborhood.
In Barcelona, the consolidated fabrics still contain many voids and gaps, that are detrimental because their compactness is diminishing but, in turn, represent an opportunity to increase the public housing stock in central positions. The # ATRI strategy proposes a method of "urban dentistry" which understands these gaps as decay caries and proposes to fill them with residential "fillings".