Multi-Objective Optimization of Energy Retrofit Strategies under Future Climate Scenarios: Balancing Economic, Environmental, and Human Comfort Objectives

This study explores a multi-objective optimization framework for energy retrofits, integrating future climate scenarios to evaluate their impact on economic, environmental, and human comfort objectives. As climate change is expected to alter temperature patterns, heating and cooling demands, and extreme weather conditions, conventional retrofit strategies may not be sufficient to maintain long-term building performance. Many existing retrofits rely on historical climate data, which may not accurately represent future energy needs. To address this, the study employs Representative Concentration Pathways (RCPs) and Shared Socioeconomic Pathways (SSPs) to generate future weather projections, ensuring a more forward-looking approach to retrofit assessment. The research utilizes EnergyPlus simulations, along with Honeybee/Ladybug, to model energy performance across various retrofit strategies. Multi-objective optimization, specifically NSGA-II (Non-Dominated Sorting Genetic Algorithm II), is applied to explore trade-offs between Life Cycle Cost (LCC), Life Cycle Carbon Emissions (LCCE), and occupant thermal comfort. The optimization process identifies Pareto-optimal solutions, balancing cost-effectiveness, energy efficiency, and indoor comfort. Retrofit measures considered include building envelope improvements, such as enhanced insulation, advanced glazing, improved airtightness, and cool roofs. The integration of cool roof technology is particularly relevant as it has the potential to reduce cooling loads, lower peak energy demand, and mitigate urban heat island effects, contributing to improved indoor comfort and reduced energy consumption. Preliminary findings suggest that climate-adaptive retrofit strategies, including cool roofs, could help improve energy performance and cost efficiency under changing climate conditions. The study provides insights for building designers, policymakers, and stakeholders, helping them develop more sustainable and resilient retrofit solutions. By integrating future climate data into retrofit planning, this research contributes to the long-term sustainability of buildings and supports efforts to reduce carbon emissions, optimize energy efficiency, and enhance occupant well-being. Future work could explore additional retrofit strategies, broader climate scenarios, and alternative optimization methods to further refine climate-adaptive retrofit planning.