Comparative Life-Cycle Assessment of restoration and renovation of a traditional Danish farmer house

Construction and operation of buildings are a major contributor to environmental impacts. Assessments of environmental impacts of buildings often focus on new buildings, while studies on the existing building stock often focus on energy efficiency renovation. However, historical and traditional buildings are of cultural and visual importance, which should be kept. Hence, a key question is if maintaining original aesthetic via restoration is at the expense of the environment or if it is possible maintain the original appearance of the building while keeping environmental impacts comparable to that of energy renovation. To investigate this, we conducted a Life-Cycle Assessment (LCA) of two options: a restoration and a renovation of an old building from 1887 located on Bornholm, Denmark. The restoration scenario focuses on the use of traditional materials and maintaining the original appearance of the house. The renovation scenario focuses on the use of modern materials and complying with energy requirements for renovated buildings. The results show that, while the impacts of the two scenarios are of similar magnitude, the restoration scenario performs slightly better in the majority of the impact categories in the default LCA-model. A Monte Carlo simulation showed that the restoration scenario performs better in, at least, 90% of the simulations for 8 of the 15 impact categories. This study indicates that restoration is a potentially viable alternative to renovation as a means for maintaining the original appearance of historical buildings to keep cultural heritage while also keeping environmental impacts at levels similar to renovation.