Occupant-centric energy retrofit evaluation and optimization for Canadian residential buildings: a life cycle thinking approach

Abstract

Energy retrofits are essential for reducing building energy consumption and associated greenhouse gas (GHG) emissions. Occupancy patterns and occupant behaviors can significantly influence building energy performance and, consequently, the effectiveness of retrofit interventions. As such, it is critical to account for occupant factors when evaluating retrofit strategies. This study proposes an occupant-centric energy retrofit evaluation and optimization framework for Canadian residential buildings, grounded in a life cycle thinking approach. The research first assessed the impact of occupancy patterns and occupant behaviors on retrofit performance using a physics-based energy modeling approach. Then, energy modeling outputs were subsequently integrated with life cycle assessment and costing to evaluate the emission and cost outcomes of retrofit packages. Finally, multi-objective Pareto optimization was applied to identify optimal retrofit packages tailored to distinct occupant personas, based on trade-offs between life cycle GHG emissions and costs. Results demonstrate that cost-optimal packages achieved over $3,500 in life cycle savings per household, while emission-optimal packages reduced life cycle GHG emissions by over 113 tonnes of CO₂eq per home. The proposed framework offers a comprehensive tool for analyzing occupant-driven variability in retrofit outcomes and supports decision-making for stakeholders aiming to implement cost-effective and low-carbon retrofit programs.

Keywords

Energy retrofits / Occupancy / Occupant behaviors / Personas / Life cycle assessment / Retrofit policy

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Funding

Mitacs

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