Life cycle assessment of energy efficient buildings

Life Cycle Analysis applications in the construction sector are growing due to the increased importance of embodied components in low energy buildings. In this study, standard building reference scenarios were compared with highly efficient building typologies, classified as low-energy or nearly Zero Energy Buildings. Energy consumptions were simulated starting from validated models while uniform assumptions, such as materials to be included, stages to be considered and coefficients of impact to be applied, were made for the LCA. The results show how the enhanced energy efficiency in the examined buildings and the reduction of their operational non-renewable primary energy requirement correspondingly causes a decrease of their life cycle non-renewable energy requirement, Cumulative Energy Demand and Global Warming Potential. A high potential in the reduction of non-renewable operational primary energy and GWP was found (until a maximum of 89% for the energy and 88% for the emissions). However, due to the shifting of impacts to the embodied components, the achievable life cycle reduction of non-renewable primary energy and emissions is lower (respectively 60% and 63% for the best performing retrofit). The benefit on life cycle CED is even lower due to the energy transition to renewables.