Balancing density and open space provision towards sustainable compact cities: Evidence from São Paulo, Brasília and Berlin

Abstract

Cities worldwide face the challenge of balancing densification and open space provision. However, few studies investigate how urban morphology influences that balance across different cities and continents. We identified eight urban morphological types characterizing high-density residential areas in São Paulo, Brasília (Brazil), and Berlin (Germany) and assessed those morphologies using seven indicators: population density, housing density, Floor Space Index (FSI), Ground Space Index (GSI), average building height, Open-Space Ratio (OSR), and average number of people per built area. Our findings from the Brazilian cities showed that intense verticalization does not automatically ensure open space and high density. Vertical morphologies showed the highest FSI values but not the highest housing densities, and had low to moderate OSR values, comparatively. Three morphologies found in Berlin (Contemporary, Half-Open and Edge) balanced housing density and OSR best (127–147 dwellings/ha, 0.5 to 0.8 OSR values, on average). Berlin's Traditional type showed the best balance between FSI, GSI, average building height and OSR, with buildings ranging from 1 to 9 storeys. It also achieved the highest housing densities (188 dwellings/ha, on average), but at a cost of OSR. Those findings suggest that a compact city model with perimetral blocks (Half, Edge and Traditional types) could provide an optimum use of urban space, if open space provision is properly considered. We further discuss the advantages and implications of block-based urban planning and design (traditional in Berlin and other European cities) in contrast to plot-based (often observed in Latin American cities).