Towards a more holistic approach to reducing the energy demand of dwellings

摘要

Buildings consume around 40% of the final energy in most countries but are also responsible for a large part of the energy use in the industrial and transport sectors. Today, most policies and market trends focus solely on the space heating and cooling demands often neglecting to consider indirect energy requirements such as the embodied energy of buildings or the transport energy of their users. This paper assesses different building scenarios located in two urban contexts by integrating the operational energy demand as well as the embodied energy of the dwellings and the transport energy consumption of the users. Results show that space heating represents at most 23% of the total life cycle energy demand over 50 years and 47% if the rest of operational energies, i.e. domestic hot water and appliances, is considered. Transport consumes 34-51 % of the total life cycle energy consumption while the embodied energy of buildings was found to be of the same order of magnitude as their operational energy. Current energy assessment of buildings therefore often only analyses a small fraction of the total life cycle energy use. We should widen its scope to account for so-called indirect energy consumption. This paper shows that a more holistic approach to the assessment of the energy demand associated with buildings is necessary if significant improvements in their energy efficiency are to be achieved.