Beyond Energy Efficiency in Building Sustainability: A Review of Emergy and Information for Systemically Characterizing Building Performance

Abstract

Sustainable buildings tend to maximize power and information rather than efficiency. The multidimensional concepts and tools provided by systems ecology and thermodynamics aid the understanding of building performance and sustainability as part of the global and complex thermodynamic phenomena in living systems—energy is not concentrated, but it flows, increasing the flow rate of useful energy. From such an extended macroscopic perspective, this paper addresses holistic eco-systemic criteria of building performance evaluation, focusing on emergy (spelled with an "m") and information—the two critical indices of extensive and intensive analysis. Emergy aggregates the utmost and upstream energetic impacts, whereas information evaluates the structural pattern of the energy-flow distribution. These indices are theoretically correlated under the principles of ecological energy transformation and are often practically compatible. To clarify the definitions and appropriate scientific contexts of the new indices for environmental building studies, we review information theory, ecological theorems, and a few pioneering studies. Emergy and information have a great potential for advanced environmental building analysis, but building-scale implementation of emergy, information, and system principles remains a scientific challenge. The findings call for further research into the improvement of building-specific emergy/information data and reliable evidence of the analogy between building and open living systems.