A holistic building life cycle energy assessment model
Authors: Stephan, Andre; Crawford, Robert
Current energy assessments of residential building energy demand focus mainly on their operational aspect, notably in terms of space heating and cooling. The embodied energy of buildings and the transport energy consumption of their occupants are typically overlooked. Recent studies have shown that these two energy demands can represent more than half of the life cycle energy of a building over 50 years.
This study presents a holistic method which takes into account energy requirements at the building scale, i.e. the embodied and operational energy of the building and its refurbishment, and at the city scale, i.e. the embodied energy of nearby infrastructures (roads, power lines, etc.) and the transport energy (direct and indirect) of its users. This method has been implemented through the development of a software tool which allows the rapid analysis of the life cycle energy demand of buildings at different scales.
A case study, located near Melbourne, Australia, confirms that each of the embodied, operational and transport requirements are nearly equally important. Embodied and transport energy consumption represent on average 63% of the life cycle energy requirements. By integrating these three energy flows, the developed method and software tool provide building designers, planners and decision makers with a powerful means to effectively reduce the overall energy consumption and associated greenhouse gas emissions associated with residential buildings.