Building retrofit for energy efficiency in existing buildings: A case study of a social residential building in France

The growing demand for sustainability and energy efficiency in the construction sector has driven retrofitting as an essential strategy to reduce energy consumption in existing buildings. Despite the availability of numerous efficient building projects, studies specifically focused on energy retrofitting and rehabilitation actions remain scarce. This work evaluates the implementation of building retrofit proposals to increase energy efficiency. Hence, a novel methodological framework is proposed to assess the building retrofit to empower the decision-making process and sustainability of existing buildings. A case study building of the Jean Carasso residence in Bezons, France is applied to evaluate the validity of the proposed framework of this study. The proposed methodological framework of this study consists of four main steps that are characterization and parameters; performance constraints; proposals and alternatives; and quantification of energy benefits. Energy Plus software was used to simulate the energy modelling of existing buildings and evaluate the building retrofit. The case study building consists of two main buildings: B1 and B2. The results indicated that the proposed methods could enhance energy efficiency in building B1 by 65.1% and in building B2 by 68.8%. This work confirms that insulation of external walls is more effective than insulation of internal walls and the simple replacement of the old windows with more efficient windows brings a significant contribution in terms of thermal transmission.