Intensive residential densification: impact on the urban morphology of Santiago de Chile

Santiago de Chile´s areas of growing centrality are currently under residential densification processes, which vary in degrees of intensity and forms of impact in the urban environment. As a result of a weak conduction of residential densification, the structural-radical transformation of the urban fabric has resulted in urban space degradation. However, residential densification is a form of urban growth that, well designed and planned, allows optimizing infrastructures and building a more complex and inclusive city. This work aims to understand to what extent urban morphology shapes these processes of urban transformation in 15 selected areas of 25 hectares; proposing typologies of residential densification based on the intensity of the process and the state of transformation of the urban fabric. Density (dwellings/hectare) is understood in systemic relation with those parameters that determine urban compactness and configure public space: lot subdvision composition, setbacks, building footprint and height, floor area ratio and mixed use index, among others. The impact of intensive densification on urban space would have three main effects: (1) the standardized tower radically fragments the fabric structure and skyline, to the extent multiple and dispersed vertical operations transform lot geometry, abruptly increase building height and lower land occupation; (2) triggers a “residentialization” effect, unbalancing existing diversity of activities and contributing to undermine urban vitality; and (3) impairs the quality of public space, by introducing exogenous typological elements (such as setbacks) and reducing contact between private space and the street.