The effect of material service life on the life cycle energy of residential buildings
Authors: Rauf, Abdul; Crawford, Robert H
Energy use and related greenhouse gas emissions of buildings have a significant impact on the environment. To reduce energy consumption in buildings, it is important to understand the energy use occurring across the building life cycle. While previous studies have shown the significance of both the energy required for building operation as well as the energy embodied in initial building construction, an understanding of the total energy embodied in replacement materials over a building’s life is not as well developed. One of the key factors affecting this ‘recurring’ embodied energy is the service life of materials. The aim of this study was to determine what effect a variation in the service life of materials has on the life cycle energy demand associated with residential buildings. The building’s initial embodied energy, operational energy and recurrent embodied energy were calculated with material service life values based on average figures obtained from the literature. These values were then varied to reflect the extent of service life variability likely for a selection of the main building materials and the recurring embodied energy recalculated for each scenario. The results from this initial study indicate that the service life of materials can have a considerable effect on the total energy demand associated with a building over its life. This demonstrates the need for further clarity around the service life of materials and the importance of considering the durability of materials when designing and managing buildings for improved energy efficiency. Results from this study also suggest the importance of including the recurrent embodied energy of buildings in building life cycle energy analyses, which in this case represented between 19 and 30% of the life cycle energy of the building.