After World War II, various architectural theories were proposed for urban development in order to tackle the societal issues and housing issues arising from the post-war trauma. ‘Streets-in-the-sky’, proposed by the English architects Alison and Peter Smithson in 1952, was one of the concepts that emerged in the post-war era and advocated the core values of human association and identity in the city. The Smithsons conceived the concept as a solution to the lack of public space on ground level due to the proliferation of automobiles, envisaging a vibrant uplifted public life. Hence, the notion gained critical acclaim in the early 1960s since it was also a response to the rigid urban planning of CIAM, prioritized community as a critical fragment in design and no long treated human as functioning machines. Nevertheless, the notion received increasingly negative feedback as more housing following this concept was built and gradually became viewed as a castle in the air. Scholars and the public no longer perceived the idea as a feasible design solution for the society. This thesis will deconstruct the concept through historical and socio-political lenses using three reference projects: Golden Lane Competition, Park Hill Estate and Robin Hood Gardens. The thesis investigates also the external and internal forces that turned ‘streets-in-the-sky’ into a castle in the air. The paper would be divided into three parts to understand the development and decline of the notion. What were the driving forces that fostered the formulation of ‘streets-in-the-sky’? How did architects implement this architectural theory into practical usage? What were the factors that led to negative public perception of the notion? Although the original ideas were not able to materialize as perfectly as expected in the 1960s, the urban values and historical values are inherited and engender an immense impact to later city development as vertical connection cores and elevated walkways re-appeared in metropolises in the recent decades.

Both urban voids and Bressoux are facing the same issue - exist in the city but do not belong to it. The voids are the by-product of urban planning, and the relationship between positive space (massing buildings) and negative spaces (voids) is barely included in design consideration. Generally, these spaces are perceived as a phenomenon of emptiness, neither productive in the urban fabric nor possessing a recognizable role in the neighborhood. Therefore, they never truly integrate into the neighborhood and indeed exist as urban segregation. However, the nature of emptiness is also regarded as a kind of spatial quality and possesses a certain degree of potential. The project aimed to reposition the role of voids by seeing them as volume and a new interior to the neighborhood. By exploring the movement between interior and exterior, inverting the solid void, it is aimed to transform voids as a mending tool to reconnect the dispersed neighborhood as well as create an alternative public space that truly belongs to the locals.