Sustainability indicators for the preliminary energy design of office buildings

The building sector currently represents 40% of energy consumption worldwide. This, combined with the characteristic long service lifespan of buildings, means that building design decisions have long lasting and multidimensional impacts on both society and the natural environment. As a result, there has been a growing interest in the assessment of buildings through the concept of sustainability, considering its three fundamental pillars: economic, environmental and social aspects. However, evaluation schemes are generally developed in the context of building declaration or certification, while few are aimed at providing decision-support during the preliminary design stages. It is during these early stages that key decisions such as overall construction principles and operation strategies are defined, generally with a limited degree of information available. In order to support decision-making during preliminary design, a set of indicators is proposed aimed at evaluating early design alternatives based on a whole life-cycle approach and according to the 3 fundamental pillars of sustainability. Indicator selection is based on database availability for calculation parameters, as well as evolution of information available and the specificity of design decisions at each design stage. Conclusions from this study are focused on the energy design of tertiary buildings, offices in particular, in the French context. The present work is divided into 2 sections: first, a state of the art study of sustainability indicators in buildings is presented; afterwards, the selected set of indicators is proposed and discussed. Conclusions and future work perspectives are also discussed.