A multi-scale life-cycle energy and greenhouse-gas emissions analysis model for residential buildings

Current 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 model and software tool which take into account energy requirements at the building scale, i.e. the embodied and operational energy of the building and its refurbishment, and at the urban scale, i.e. the embodied energy of nearby infrastructures (roads, power lines, etc.) and the transport energy (direct and indirect) of its occupants. All associated greenhouse-gas emissions are also quantified. A case study, located near Melbourne, Australia, confirms that each of the embodied, operational and transport requirements is nearly equally significant. Embodied and transport energy consumptions represent on average 63% of the life-cycle energy and 60% of the life-cycle greenhouse-gas emissions. The developed holistic model provides building designers, planners and decision-makers with a powerful means to reduce the overall energy consumption and associated greenhouse-gas emissions of residential buildings.