Introverted and knotted spaces within modern and contemporary urban fabrics: passages, gallerias and covered squares

Passages, gallerias and “urban” atriums are morphological configurations of a prevalent phenomenon within modern and contemporary cities, in which there has been a further evolution of the specialized urban fabric. The urban and social changes caused by the Industrial Revolution have modified the relationship between public spaces and urban fabric, by defining new connections between urban organism and covered places -usually devoted to commercial or tertiary functions-. French passages and British arcades have had an active role within the existing fabric, relating their own architectural structures to the buildings (existing or new ones) and to the pre-existing vehicular system. In both those types it is possible to recognize a common morphological substrate, that is a radical answer to analogous problems: passages, arcades, and gallerias are covered walkways due to the modern necessity to have gathering places and commercial areas far away from urban traffic and sheltered from weather. The covered pedestrian walkways experienced in Paris, London, Munich are the first examples of a morphological process that can be called “introversion of the routes”, that has been intensified also within the urban dynamics of contemporary cities. Architectural experimentation has led to the construction of unconventional public spaces that, both in linear organical systems (passages, gallerias) and in nodal organisms (urban atrium), are integrated within the urban fabric. The aim of this research is to illustrate the typological development of passages, gallerias, and covered squares, identifying the processual nature of those public spaces and projecting them into a new urban vision.