The spatial formation of multi-use urban areas is one of the main reasons for the emergence of some positive or negative social phenomena among the population in Egypt, where the value of the urban space lies in the total social and cultural relations that arise in it and its ability to create opportunities for interaction between a different group of individuals. Hence, this research discusses the concept and evaluation of urban spaces in terms of the positives or negatives of multi-use areas and their role in achieving social sustainability in closed urban communities in Greater Cairo. Therefore, the study aims to evaluate mixed-use urban spaces, from a functional and social perspective, which is a tool to increase the social sustainability of urban communities in general and closed mixed urban communities in Egypt in particular. So that some conclusions and recommendations can be made on how to establish for mixed-use lands as a basic approach in sustainable urban development.

This paper deals with many important axes, the first axis deals with the urban space, the most important concepts, foundations and standards necessary to design a sustainable urban space. The second axis deals with the mixed-use in terms of concept, historical development, positives and negatives. While the third axis deals with social sustainability in terms of concept, theoretical background and its elements. The fourth axis deals with the criteria and principles presented from the perspective of Habitat Organization to assess the overlap of mixed land uses (in Al Rehab and Ashgar Cities) and measure the success of many variables such as, mixed land use, urban spaces and social sustainability in these cities to reach the interrelationship between these variables. Where the research proved a direct relationship between these variables, the greater the percentage of multi-use urban spaces, the more social sustainability.