Comparative LCA Study of Preservative Restoration Strategies for 1970s Single-family Houses in Denmark

In Denmark, around 1,700 single-family houses are demolished. These are buildings that are often built in a period with an architectural style that is appreciated. Still, poor maintenance, high energy consumption, and too small living units mean the buildings are increasingly being demolished. The rising rate of demolitions contrasts with emerging findings that the refurbishment of these buildings not only promotes the preservation of their historic architectural status but also provides a lower environmental impact compared to new construction. However, how the refurbishment is carried out is not unimportant for preserving these values. This study aims to compare the environmental impacts of four refurbishment strategies, including light biogenic-based restorations to heavy energy renovations, on a case study of a typical 1970 single-family house in Denmark that, based on the building techniques and architecture representing typical 1960-1970 construction in northern and western Europe. By assessing these strategies, we identify the refurbishment strategy with the lowest environmental impact, providing new insights into sustainable renovation practices through restoration that aligns with architectural and heritage preservation. Using LCA analyses, the study finds that the two restoration scenarios emit the least CO₂-eq per m² annually, with the biogenic scenarios having the lowest impact.