Space organisation of urban blocks is a significant topic of urban design field to achieve correlated urban parts that enhance the variety in urban spaces. However, the rapid urban transformation experienced in the Turkish cities resulted in the generation of similar urban blocks with the lack of spatial variety. Therefore, a re-evolution of space organisation concepts for urban blocks emerges as a design problem in order to cope with the defined problem. From this point of view, the interfaces among public, common and private spaces as the formative parts of space organisation process constitute the essence of this study. Thus, the morphological elements of urban blocks as street, plot and building are constantly reshaped and redefined based on the correlations of this realms. Within this scope, Conzen&rsquo / s town plan method has been adopted in this study for Bah&ccedil / elievler Housing Cooperative Site, to reveal the transformation experienced and the changing relations of street, plot and building throughout the morphological formation processes. In the light of this problem case and method implemented, this research indicates that in Bah&ccedil / elievler, the changing relations between street, plot and buildings are an outcome of the interfaces among public, common and private regarding the permeability along boundaries. Based on this outcome, this study suggests that a new understanding of space organisation in urban blocks regarding the interfaces among public, common and private spaces as counterparts of street, plot and buildings arises as a significant issue that needs to be reconsidered by urban designers, planners, architects and public authorities while defining the design and planning process.