Does climate change significantly impact the benefits of existing building energy-saving retrofit? evidence from a parametric study

The existing building stock is substantial, with high energy consumption, making building energy retrofitting a key strategy for the construction industry's response to climate change. However, the significance of climate change as a dynamic factor influencing the effectiveness of retrofit strategies, and its implications for retrofit decision-making, remain inadequately defined. This study aims to establish an analytical framework for assessing the impact of climate change on retrofit benefits, comparing its influence with that of other factors in terms of magnitude and significance. The framework incorporates building energy consumption and economic indicators related to retrofitting. A weather data downscaling approach, based on Morphing, is employed to generate weather data for the years 2020, 2050, and 2080, derived from the IPCC's A2 emission scenario. A set of 12 building models was developed with a 10-story office located in different climate zones with various retrofitting schemes. To account for the relative impacts of multiple factors, a model library of 144 models was constructed, considering the effects of building lifespan, discount rate variations, price fluctuations, and climate change. These models were subjected to energy consumption simulations, as well as cost and net present value calculations. Sensitivity analysis and inter-group difference tests revealed that climate change significantly impacts the energy-saving retrofit benefits of buildings, with variations across different climate zones. The findings provide evidence for incorporating climate change factors into future building retrofitting and offer valuable insights for the development of building energy retrofit decision-making models.