In light of the current climatic changes, many countries are seeking to use Green Infrastructure to integrate with gray infrastructure due to their environmental, social and economic benefits. The green infrastructure networks are distinguished by the diversity of their applications, whether at the level of the building, streets or the urban district, and the integration between these various applications maximizes their environmental impact. The roof gardens represent one of the applications of green infrastructure networks that research focuses on and proposes to apply them on a wider scale in Egypt, because most Egyptian cities suffer from environmental, social and economic stress. The research aims to clarify the legislative and executive challenges of roof gardens in new cities, in addition to the benefits resulting from designing roof gardens on residential units. The study deals with using the technology of rooftop garden cultivation in new cities as a means to achieve sustainability. The research presents theoretical studies of roof gardens and an applied study in one of the new cities - Sheikh Zayed City - and the research concludes with an applied methodology for implementing this model in many new cities.