Reliability of building embodied energy modelling: an analysis of 30 Melbourne case studies

Abstract

Building design decisions are commonly based on issues pertaining to construction cost, and consideration of energy performance is made only within the context of the initial project budget. Even where energy is elevated to more importance, operating energy is seen as the focus and embodied energy is nearly always ignored. For the first time, a large sample of buildings has been assembled and analysed in a single study to improve the understanding of the relationship between energy and cost performance over their full life cycle. Thirty recently completed buildings in Melbourne, Australia have been studied to explore the accuracy of initial embodied energy prediction based on capital cost at various levels of model detail. The embodied energy of projects, elemental groups, elements and selected items of work are correlated against capital cost and the strength of the relationship is computed. The relationship between initial embodied energy and capital cost generally declines as the predictive model assumes more detail, although elemental modelling may provide the best solution on balance.

Keywords:

• Accuracy
• capital cost
• embodied energy
• capital cost
• modelling.

Acknowledgements

The authors of this paper would like to thank the kind assistance of Associate Professor Graham Treloar from the University of Melbourne for the use of his input–output‐based hybrid method for embodied energy analyses and for his supervisory advice and guidance in this research, Computerelation Australia Pty Limited for making available LIFECOST ^TM software for operating cost analyses, and Davis Langdon Australia for permission to use their data in the case studies. Without their cooperation this research would not have been possible.