Comparative environmental and cost analysis for renovation and reconstruction in multi-family social housing

Renovating both public and private buildings was singled out, in the European Green Deal, as a key initiative to drive energy efficiency in the sector and deliver on existing goals. While literature studies comparing renovation and reconstruction options exist, most focus on operational energy use, often neglecting other stages. This paper compares renovation and reconstruction scenarios for a social housing building in Ghent, Belgium, considering relevant life cycle stages and indicators. Life Cycle Assessment and Life Cycle Cost are conducted for two renovation scenarios and three reconstruction scenarios, with energy performance evaluated based on the Flemish Energy Performance Certificate show that decarbonized electricity mix reduces operational emissions by up to 58%, while optimal renovation achieves 18% cost savings compared to 4% for conventional reconstruction over a 60-year lifespan. Bio-based reconstruction reduces embodied carbon by 34% compared to conventional concrete construction. These findings introduce novel correlations between economic and environmental implications of renovating or reconstructing, assuming different energy levels and material options.