LEEUWARDEN DECLARATION ADAPTIVE RE-USE OF THE BUILT HERITAGE: PRESERVING AND ENHANCING THE VALUES OF OUR BUILT HERITAGE FOR FUTURE GENERATIONS Adopted on 23 November 2018 in Leeuwarden Europe has a rich and multi-faceted built environment, incorporating strong spiritual, cultural, social and economic values. Due to evolutions in our economies and societies, many heritage sites, whether listed or not, are nowadays disused or have lost the functions for which they were originally built – notably industrial, religious, and military sites, but also more contemporary buildings from the second half of the twentieth century. However, heritage buildings that have lost their original function still embody cultural, historic, spatial and economic values. Adaptive re-use offers itself as a strategy aimed at preserving those elements that contain these values, while at the same time adapting the place for new uses. New functions are thus brought together with heritage values in an active and meaningful dialogue. Throughout the European Year of Cultural Heritage, within the framework of the initiative entitled Heritage in Transition: Re-imagining industrial, religious and military spaces for the regeneration of urban and rural areas, the benefits of adaptive re-use strategies, as well as good practices, challenges and barriers to their implementation, have been intensively discussed. The present Declartation aims to take stock of lessons learned over the Year and reflect on good practices supporting quality interventions.