Since the mid-twentieth century, the process of modernization caused an adaptation of westernized prototypes of residential neighborhoods in Greater Cairo Region. This evolution caused a relevant evolution of various prototypes of urban spaces, an evolution from traditional neighborhoods where street works as public space to new planned neighborhoods that concern quantitative provision of urban spaces as internal gardens inside superblock. The evolution was attractive for residents who escaped crowded traditional neighborhoods and claimed quantitative provision of urban spaces with well-designed landscape to enjoy better living conditions. Egyptian National Organization for Urban Harmony developed urban space design guidelines, to ensure quantitative and accessibility criteria. However, observation of urban spaces in new cities revealed failure to host residents and probably have negative impacts on social inclusion, cohesion, and participation. One reason behind that failure is the lack of empirical knowledge of expected impacts of design guidelines on social behavior. This research examines social sustainability of urban space configuration in four prototypes of neighborhoods, it also questions how socially sustainable are NOUH2010 design guidelines. The research depends on ethnographic observation and questionnaire survey that were conducted in selected neighborhoods. The paper reports, based on empirical findings, that modern urban spaces with quantitative provision of urban-spaces, hierarchical distribution, merged and central location, good accessibility and well-designed landscape are short sighted to achieve urban social sustainability; rather qualitative mixed use is most influential factor to encourage social inclusion, interaction and participation as by-product of movement and as subsidiary to other attractive activities.