The Circular City and Adaptive Reuse of Cultural Heritage Index: Measuring the investment opportunity in Europe

•The new Circular City Adaptive Reuse of Cultural Heritage Index (Index) applies 15 indicators in three dimensions: cultural stock, environmental stewardship, and socioeconomic factors.•The Index defines the investment opportunity for the rehabilitation and reuse of cultural heritage buildings for circular cities.•190 cities of the European Cultural and Creative Cities Monitor are analyzed and ranked.•The 50 highest-ranked cities of the Index represent only 12 countries: France, Germany, Spain, Luxembourg, Netherlands, Sweden, United Kingdom, Italy, Norway, Switzerland, Finland, and Portugal.•The highest-ranking cities should make discretionary investments now to allocate legislative time, budget, human resources, and political capital to ARCH. The long-lived, culturally relevant, and unique buildings of Europe's urban landscapes embody the values of the circular economy (CE) and sustainability. They are central to urban identities, generation after generation. Furthermore, adaptive reuse of cultural heritage buildings (ARCH) contributes to slowing down the extraction of natural resources, reducing energy for new buildings, and reducing construction and demolition waste and greenhouse gas emissions. ARCH's inherent characteristics distinctly express the 2019 European Green Deal's CE objectives and the 2020 building Renovation Wave Strategy. In this context, European city managers, heritage conservationists, and other stakeholders need a systematic method to characterize the investment opportunity for ARCH, considering CE. To fill this methodological gap, this study introduces a new composite indicator called the Circular City Adaptive Reuse of Cultural Heritage Index.