Le Corbusier's Unité d'Habitation imagined a "vertical neighborhood," a building able to integrate housing, commerce, leisure, and collective spaces within a single structural organism. Around the same time,
Jane Jacobs argued that diversity of use is what produces safety, identity, and social life at the street level. Later,
Rem Koolhaas, in
Delirious New York, described the skyscraper as an early experiment in "vertical urbanism," capable of stacking incompatible programs under one roof. In cities like Tokyo and Hong Kong, this ambition matured into complex hybrid buildings where different uses, such as transit hubs, retail, offices, hotels, and housing, coexist and interact continuously.
