Population and Morphological Change: A Study of Building Type Replacements in the Osaka-Kobe City-Region in Japan

As cities adapt to new needs and challenges, their forms change in close relation to population dynamics. This article focuses on the link between population dynamics and the evolution of building hull types. The case study is the Osaka-Kobe city-region in Japan, a country globally witnessing an intense population decline. Morphometric indicators are coupled with a tree-like classificatory model in order to label buildings into consistent classes between two different periods (2003–2004 and 2013–2014). The building class distributions and their evolutions are studied in conjunction with population censuses. Urban adaptation processes are particularly accounted for through the study of the replacement of building types. Results show that, among other things, townhouses in traditional neighborhoods are gradually being replaced by small-size collective complexes. In far outlying areas, people are still eager to move and live in detached single-family homes despite a global context of population decline. Finally, central places are increasingly filled by narrow almost-adjoining towers. Relations between building types and population dynamics, detailed through maps and statistics, show that peoples are increasingly concentrating in central locations associated with specific building types, while some other peripheral locations are concerned by both a disappearance of specific building types and a population decline.