The research deals with the economic importance of urban heritage buildings, and the mechanisms for applying heritage sustainability for urban heritage buildings, through presenting the various definitions of urban heritage buildings and sustainable economic investment, which constitute an obstacle to achieving sustainability for this type of building, which is governed by a set of local and international rules for rehabilitation, and refrains the private sector from participating in development and rehabilitation of architectural heritage buildings projects due to the various organizational and administrative restrictions they carry and what may impede achieving the expected material return from these projects, or achieve the financial feasibility of these projects for the private sector, making these projects a great financial burden on the budget The research presents a local experience to activate the role of the private sector in the sustainable investment of urban heritage buildings in Egypt, and the various available possibilities that have contributed to the success of that experiment and the achievement of that development, by presenting the experience of the participation of the business sector in the renovation and rehabilitation of heritage buildings in the downtown Cairo area, which is considered as one of the contemporary projects for the development of the urban and architectural heritage of the Khedivial Cairo area and the rehabilitation of heritage buildings in Egypt.