Abstract

The presence of small open spaces between houses is a common feature in existing Japanese neighborhoods. The redefinition of these spaces through architectural design can contribute to the regeneration of the urban fabric. This study is focused on the significance of open spaces within architectural territory, not as negative leftover spaces, but rather as positively designed units. In this regard, architecturally designed open space that connects the building site to the surrounding urban fabric is referred to as urban void. This article aims to discuss three contemporary theories, by Japanese architects, on architectural approaches that are based on the formation of urban voids. These theories are “Tokyo Metabolizing,” “Site Determined,” and “Group Form.” Three levels for positivity of urban void are defined and their related factors are extrapolated, based on which the theories and their representative collective housing projects are analyzed and compared. Also, the position of urban void in the process model of each theory is clarified. Finally, it is shown that an urban void has a double identity—it belongs to the internal order of an architectural composition, while also being a part of the external order of the urban fabric.