This study presents an in-depth analysis of 69 case studies focusing on the energy retrofit of historic buildings, uncovering challenges, best practices, and lessons learned to balance energy efficiency improvements with heritage preservation. The findings highlight several challenges encountered during renovations, such as complex heritage evaluations, restrictions on alterations, coordination issues with authorities, technical limitations, higher investment costs, and knowledge gaps. On the other hand, identifying factors promoting renovation, including demonstrating energy savings while respecting heritage, early collaboration between planners and authorities, and quantifying investments, could incentivize owners and authorities. The limitations of a still-limited sample size, occasional incomplete data, and potential sample bias call for cautious interpretation of the presented analysis. Despite these, the study provides valuable insights into successful projects, emphasizing the need for scalability, knowledge transfer from innovative policies, and targeted policy-making for successful replication. The study concludes with a call for further development of the HiBERatlas (Historic Building Energy Retrofit atlas), an extensive resource for historic building renovation, expanding its database, collaborating with agencies, and tailoring guidance for stakeholders to foster energy retrofits in heritage buildings.

A new methodology for long-term monitoring of climate change impacts on historic buildings and interiors has been developed. This paper proposes a generic framework for how monitoring programs can be developed and describes the planning and arrangement of a Norwegian monitoring campaign. The methodology aims to make it possible to establish a data-driven decision making process based on monitored decay related to climate change. This monitoring campaign includes 45 medieval buildings distributed over the entirety of Norway. Thirty-five of these buildings are dated to before 1537 and include wooden buildings as well as 10 medieval churches built in stone while the remaining 10 buildings are situated in the World Heritage sites of Bryggen, in Bergen on the west coast of Norway, and in Røros, which is a mining town in the inland of the country. The monitoring is planned to run for 30 to 50 years. It includes a zero-level registration and an interval-based registration system focused on relevant indicators, which will make it possible to register climate change-induced decay at an early stage.

The Swedish National Research programme for Energy Efficiency in historic buildings was initiated in 2006 by the Swedish Energy Agency. This article gives an overview of the programme: objectives, projects and the general results of the programme. The research programme aims to develop knowledge, methods and technical solutions that contribute to energy efficiency in historically valuable buildings without destroying or damaging the historical value of the buildings, including decoration, furnishings, interiors or equipment. The programme is not limited to listed and monumental buildings but covers a wider range of historic buildings that account for a large part of the energy use in the building sector. For one and two-family houses, around 25 % of the energy use is associated with buildings built before 1945. The same number for multifamily houses is around 15 %. The programme is currently in its third consecutive four-year-stage. Previous four-year-stages were completed in 2010 and 2014. Over time, the scope of the programme and the projects have developed from mainly dealing with indoor climate control in monumental buildings towards addressing more general issues in the much larger stock of non-listed buildings. Technical research, based on quantitative analysis, dominate throughout all three stages, however most projects have had interdisciplinary components. The results from the programme have been presented in 31 journal papers, 67 conference papers, five books and five PhD theses. The projects have also contributed to CEN standards and resulted in a number of Bachelors and Master’s theses. An equally important long-term effect of the programme is that the number of Swedish researchers in the field have increased from practically none in 2007 to 18 senior researchers and twelve PhD students from ten universities in 2014. The research programme on Energy Efficiency in historic buildings is unique in an international context. Hopefully it can serve as an example for other countries on how to address an important interdisciplinary research challenge.