Adapting Historic Cities Towards the Circular Economy: Technologies and Materials for Circular Adaptive Reuse of Historic Buildings

In recent years, there has been a growing international governmental focus on the emergencies of climate change and biodiversity, in relation to the objectives of the Paris Agreement. There is a strict relationship between climate change and the city. All the activities that take place in an urban context contribute to climate change. In fact, a large amount of resources is consumed in cities with negative external effects in terms of pollutants and climate-altering emissions. In this scenario, the construction sector is considered one of the fields that contributes more to environmental depletion and climate change due to the continuous use of materials, energy and manufacturing technologies. Governments are striving to find new sustainability solutions and strategies both for the construction of new buildings and for the redevelopment/reuse of existing ones, including historic buildings. This contribution aims to identify strategies and tools for historic buildings renovation and energy retrofit to reach climate targets in the perspective of a more circular and sustainable building stock. A review of recent literature was developed to explore innovative materials and technologies that can be employed for energy retrofit of historic heritage buildings, including the analysis of exemplary case studies, taking into consideration the needed balance between cultural values conservation and climate change-related objectives. An abacus of suitable materials and technologies was developed and overall recommendations are proposed to enhance policies on historic buildings retrofit regulations.