Circular economy in the heritage conservation sector: An analysis of circularity degree in existing buildings

The construction and building sectors are responsible for a large part of the consumption of energy and natural resources. The concept of the circular economy, a closed-loop system that uses waste as a resource, can be used as a strategy to mitigate this consumption by preserving and reusing historic buildings rather than demolishing and rebuilding them. In this paper, a quantitative analysis of the application of the circular economy to existing buildings and their preservation is conducted by examining the extensive literature on the circular economy approach and field studies to define and determine the degree of circular economy and contribution to environmental benefits. The study showed the importance of restoration, continuous use, rehabilitation, and renovation of historic buildings. It also showed that the most important parameter that determines the proximity to the circular economy is a constant use that adapts over time. In addition, the use of the building and its old traditional systems in multiple functions and by different users also increases and promotes the circular economy. The conclusions also highlight the need for concrete assessment parameters and appropriate indicators of the degree of circular economy in historic buildings, so that it might be possible to learn from these structures for contemporary buildings.