Life Cycle Assessment of a French Single-Family House Refurbishment: The “Bat-Eco2” Case Study

Abstract

This paper presents the methodological choices and the results of a complete life cycle assessment (LCA) carried out on a case study of building refurbishment. The LCA case study refers to the Bat-Eco2 French project which considers both environmental and economic performance of the refurbishment single-family house, located in the North of France.The LCA methodology is compliant with EN 15978, detailing the refurbishment life cycle stages, i.e. products, construction processes, use and end of life. The functional unit and the system boundaries are presented and discussed. A reference service period of 50 years was used. The construction product and equipment lifetimes were drawn from the social landlord data. The modeling was performed using Simapro v. 8.3.0.0 software, with Ecoinvent database v. 3.3 and ILCD environmental impact indicators. Energy consumption and water consumption were taken into account in the use stage along with replacements and maintenance.The main contributors to the environmental burden correspond to construction products and equipment, replacement and energy consumption. The related potential impact contributions range from 66% to 94% for most environmental indicators. Focusing on climate change indicator of the construction product, two thirds of this impact category come from three contributing construction materials which are the ground insulating EPS, the ground and wall ceramic tiles and the PVC windows frames. As for contribution of the replacements, it comes from window frames, from front door and inside doors, and from replacements of the boilers. Natural gas energy vector contributes mainly to use stage impacts. The reliability of those results are strengthened by uncertainty analysis. Hotspots are dependent both on the chosen reference study period of 50 years and on the product and equipment lifetimes.