The specialists of the United Nations are doing their best for improving the developing countries in various ways, such as creating appropriate strategies in order to develop these countries, especially in the environmental aspects. Definitely, creating an effective strategy for organizing the urban design of the developing countries is very important for improving their environmental conditions, particularly for the crowded cities in these countries. In this regard, five recommendations have been determined as UN-Habitat's principles for achieving a good urban design. These principles planning guidelines are; planning adequate space for streets and an efficient street network, selecting acceptable residents' density, organizing mixed land-use, affording social mix occupation and limited land use specialization. These UN-Habitat's principles can support the countries in alleviating urban sprawl in addition to achieving sustainable housing development and helping in building a new sustainable relationship between the dwellers and the urban space for increasing the value of lands. Accordingly, these principles can be employed for assessing any Egyptian urban area and determining its compatibility with these principles. In this paper, Al-Yasmeen neighborhood in New Cairo has been considered as a case study to figure out its compatibility with the UN-Habitat's principles. The results of analyzing the considered areas related to each principle reveal that there are significant deviations from the suggested percentages of the UN-Habitats. Hence, some interventions have been suggested to enhance the compliance of such areas with the recommended values.