This Special Issue on energy efficiency in historic buildings addresses the balance between two different aspects of sustainability, i.e., environmental and socio-cultural. On the one hand, amidst growing pressure to reduce energy costs and greenhouse gas emissions, historic buildings stand for a considerable part of societal energy use that necessitates energy-efficient interventions. On the other hand, the historic building stock is an important cultural and material resource that merits management and preservation for the benefit of present and future generations. Thus, we must find ways to balance the needs of historic building conservation and energy conservation to facilitate the sustainable management of historic buildings. This Special Issue calls for research on a multitude of aspects, with various scientific perspectives, from the natural sciences and engineering to the social sciences and humanities. The following topics are meant to illustrate the possible scope of the Special Issue rather than exclude novel topics: Policies at international, national, and local levels – Conflicts of interest and ways forward; Decision-making for the planning of energy refurbishment in individual buildings as well as building stocks; Understanding the historic building as a technical system – simulations, risk assessment of measures, and balancing supply and demand; Development of new technical solutions appropriate for various types of historic buildings; Multi-criteria assessment of measures – life-cycle perspectives on environmental impacts and costs integrated with the impact on heritage values and aesthetics; Users’ aspects in the planning of energy retrofits and energy management – attitudes, lifestyles, and collaboration. What are the drivers/motivators? Values and valuation, historic buildings are defined by their heritage significance – how are the values defined and introduced into the decision-making process on energy efficiency? Best-practice case studies presenting state of the art both in terms of achieved results and methods; How is energy refurbishment planned and carried out in practice, and what are the roles for professionals in architecture, preservation, and engineering?
Keywords: historic buildings; energy efficiency; heritage; policies; decision-making; building physics.