Retrofitting for Humans: An Occupant-Centric Energy Retrofit Planning and Decision-Making Framework for Canadian Residential Buildings

Abstract

Energy retrofits play a significant role in reducing building energy consumption and associated carbon emissions. Many studies have proved that occupant-related factors can affect building energy consumption and post-retrofitting outcomes. Thus, the identification of optimal retrofit strategies can depend on the occupants and their behaviors. While Canadian municipalities have introduced various retrofit programs and financial incentives to improve the penetrations of energy retrofits, the role of occupants in retrofit planning and decision-making has seldom been studied. This study aims to develop an occupant-centric energy retrofit planning and decision-making framework for Canadian residential buildings while considering occupancy patterns, occupant energy use behaviors, and personas. The study investigated the effect of occupancy patterns and occupant energy use behaviors on energy retrofit outcomes. A multi-objective optimization and decision-making tool was developed to identify Pareto fronts and optimal retrofit packages for specific personas based on life cycle cost and emission performance. A simulation-based approach using EnergyPlus was adopted in the case study analysis to evaluate energy retrofit performance. The results indicate that retrofit outcomes can vary considerably under different occupancy and behavioral conditions. Cost-optimal retrofit packages can produce life cycle cost savings of over 3,500 $/home, while emission-optimal retrofit packages can deliver life cycle emission reductions of over 113 tonCO2eq/home. The proposed framework can provide a holistic approach to investigate the role of occupant-related factors on energy retrofit outcomes and help stakeholders identify optimal energy retrofit packages and develop large-scale retrofit programs in Canada.

Keywords: energy retrofits, occupancy, occupant behaviors, personas, life cycle assessment, retrofit roadmaps