"Approaching Sustainability: The main aim is to promote sustainable development. Through an integrated vision which is not a "uni-dimensional' tool, but co coordinating all environmental, economic and social aspects, to adopt a more integrated and cross cutting approach to sustainable development issues. Implement integrated principles for the sustainable planning, construction, operation, maintenance and use of buildings and landholdings. Sustainability refers to the influence in three areas: the environment, the society in which it operates and its economic impact. Traditionally, success is related to financial success; sustainability requires considering a "triple success measurement" of environmental, social factors in addition to the economic. Potentials of Gated Communities: Gated Communities are seen to be an enclave of housing, common to conventional suburban developments, the putative purpose of these communities varied among their residents, their owners - Developers- and Architects. Within a new Paradigm - Sustainability - it is seen to have high potentials to be adapted to serve in approaching the notion "Sustainable Development". For sustainability, a review of the literature that deals with this issue is carried out, where the main principles of sustainability are found to be aiding in the application of the formulation; an appraisal approach is suggested through the suggestion of a sequence of actions. The conclusions are applied in the evaluation of an existing project in one of the new settlements in New Cairo.An Appraisal Approach: An analysis to the area of study is divided into three phases: the first is a wide scope analysis concerning the evolution of New Cairo, and introducing the final report for the New Cairo extension, showing the master plan concerns and bases. The second phase is introducing El Rehab City (ERC) as one of the new communities within New Cairo, showing its context identified through a number of factors such as the topographic setting, the surroundings, street patterns, land use patterns, dominant unifying open spaces, major barriers on the edges, and similar factors. The third phase is the analysis of the residential pattern and the public land use of E.R.C.. Co operation achieves Sustainability: It was resulted to the possibility of applying most of the proposed approach, the theoretical part emphasize that sustainable development is not a single policy or plan that is incorporated into one department or function. It is a framework for decision making to be used across all sectors and at all levels. The conclusion from practical part confirms what was in the theoretical part, focusing on promoting sustainability through improving governance through coordinated efforts that link agencies, departments, and central government with local governments. In addition, to incorporate project appraisal techniques that includes environmental and social costs and benefits, and involves citizens in decision-making. In addition, to promote ethics and values that reflects sustainable development."