Analysis of the embodied energy of construction materials in the life cycle assessment of Hellenic residential buildings

As the operational energy use in new constructions is moving towards nearly zero energy buildings, the embodied energy of buildings is gaining more importance. This work elaborates the importance of embodied energy in Hellenic residential buildings by comparing the primary energy consumption during their life cycle. Field surveys were used to collect relevant data from local manufactures and determine the embodied energy coefficients of popular construction materials. The derived embodied energy intensities (EEL) and the calculated primary energy use intensities (EUL) are then used for benchmarking the buildings' energy and environmental life cycle performance. The EEL value ranged from 3.2 to 7.1 GJ/ m(2), compared with annual primary EUL of 0.3 to 3.9 GJ/m(2). The initial and recurrent embodied energy of building construction materials over the lifetime of a building can reach up to similar to 30%. The analysis quantified the time it takes for the operational energy savings resulting from energy conservation measures that are implemented in existing dwellings to recover the embodied energy impact of the new materials or products that are used. For individual measures, the average recovery time ranged from 1 to 6 years, and up to 10 years from more conservative estimates. For a combined scenario it approaches similar to 2 years or similar to 3.5 years, respectively. (C) 2020 Published by Elsevier B.V.