Integrating residents' heating practices into energy retrofit decision-making: a sufficiency-oriented approach

Current energy-efficiency retrofits often rely on standard assumptions about thermal comfort, overlooking the diversity of residents’ heating practices and promoting a one-size-fits-all approach. This can lead to resource-intensive interventions that fail to deliver proportional energy savings, cost-efficiency, and carbon emissions reductions. Addressing this gap, this study aims to integrate residents’ heating practices into the decision-making process to rethink the scale of envelope retrofits. Using Dutch social housing as case study, we conducted a simulation-based analysis to evaluate how residents’ heating practices (setpoint temperatures and number of rooms heated) influence retrofit outcomes in terms of energy savings, cost-effectiveness, and environmental impact. Our findings show that deep envelope retrofits perform well under standard assumptions of uniformly heated homes. However, their effectiveness is reduced by up to 80% in households with more economical heating practices, resulting in long payback periods (up to 91 years) and limited environmental benefits, as the embodied carbon of materials may not be offset by operational savings. By aligning retrofit strategies with residents’ heating practices, we identified more suitable solutions, such as moderate retrofit or targeted measures combined with personal comfort systems (PCS), that deliver higher cost-effectiveness and environmental benefits. We also quantified the potential of sufficiency-oriented practices, such as lowering setpoints or heating only the living room, demonstrating that they can achieve energy and carbon reductions comparable to deep retrofits, but at lower costs. These findings offer a novel perspective by tailoring energy retrofit to residents heating practices, providing valuable insights for more effective approaches for decarbonization strategies.