Embodied CO2 Emissions in Building Construction Materials of Hellenic Dwellings

As current research moves towards zero energy buildings, it is important to minimize the total energy consumption and environmental impact of a building during its lifecycle. Total energy consists of the operational energy and the embodied energy, which is related to the embodied CO2 (ECO2) emissions that contribute to the greenhouse phenomenon. This paper identifies the basic construction materials of four typical Hellenic dwellings and estimates their environmental impact in terms of ECO2. To this end, a material analysis is required. ECO2 is estimated by multiplying material masses with the corresponding ECO2 coefficients (kgCO2/kg). Due to lack of a comprehensive Hellenic database, data from an international database are utilized. The results provide practical baseline indicators for the contribution of each material in terms of mass and ECO2. Concrete is the dominant material in terms of mass, while steel dominates in terms of ECO2. In one case, the materials of the major electro-mechanical installations are also considered; their contribution in terms of ECO2 is low compared to that of the construction materials. Finally, CO2 payback time related to the replacement of building openings in order to upgrade its energy performance is demonstrated in one of the cases.