Practical Solutions for Building Envelope Retrofitting of Historic Buildings in Cold Climates

Improving the energy efficiency of buildings is one of the main strategies to reach the European target to reduce greenhouse gas emissions. As most of the future building stock is already built, retrofitting existing buildings will play a significant role in reaching this goal. In Norway, buildings that undergo full retrofitting must fulfil the same energy efficiency requirements as new buildings. This is challenging, especially in the case of historic buildings. Improvements should not damage or change the existing structure. As it is often challenging to retrofit historic buildings, this paper aims to provide practical guidelines for building envelope retrofitting as well as identify key points that need to be taken into consideration in the design phase. First, retrofitting measures recommended in historic case study buildings in Norway are analyzed. Second, an overview of typical challenges for retrofitting historic buildings is given. These are identified from literature review and from experiences during the design phase. Interviews with public building owners, contractors, consultants and architects were conducted to discuss challenges from different perspectives. Finally, findings from the literature, interviews and case studies are discussed to identify similarities.