The demand growing of energy is offset by the weakening of the generating capacity of power due to the war conditions in Syria. As the windows are the means of optical communication between inside and outside of the building, the source of the ventilation and the natural lighting, thus having an important effect on the thermal performance of the building, which affects the consumption of energy. so the search relied on proposing alternatives for glass to test its thermal performance, the choice of alternatives was based on the diversity between the values of solar radiation permeability and the visual light in addition to enumeration of the layers, to which end the computer simulation method was adopted and the results were compared to a model Standard (single-transparent). The results of the comparison showed that the amount of energy saving could be as high as 35% for the face of the sun-exposed facades directly. By reducing the permeability of the total glass of solar radiation and increasing the permeability of the visible light to increase the amount of natural illumination, plus the adoption of a Multi-layered glazing system , the study recommended that appropriate glass selection must be taken into account in the early design phase