A review of environmental impact indicators of cultural heritage buildings: a circular economy perspective

This paper is the first in-depth review of the state of the art of environmental impact indicators for adaptive reuse of cultural heritage (ARCH) buildings from a circular economy perspective. Buildings are a necessary component of sustainability planning because they are significant consumers of natural resources, producers of construction and demolition waste, and contributors to greenhouse gas emissions. In addition, buildings, particularly ARCH buildings, are long lasting; therefore, measuring and managing their environmental impacts is crucial to achieving the universal vision of a sustainable, low-carbon economy. The research answers the questions, 'What are the environmental impact indicators used by individual ARCH building project analyses?' and 'Are the most commonly used indicators reflecting Circular Economy concepts?' It synthesizes and defines current practice in the field whilst highlighting the gaps between practice and policy. Although the term 'Circular Economy' is not explicitly and routinely used in the literature, related concepts such as life cycle analysis, energy consumption reduction, energy efficiency, and embodied carbon/energy are evident at the project level. Concrete and measured environmental indicators are not mainstream. However, narratives of environmental protection feature prominently in the literature, indicating an environmental motivation for repurposing cultural heritage buildings. Further, there is a gap between common indicators of circularity and the ARCH building project level indicators shown in the dataset.