Renewal of aging residential buildings for electricity saving and carbon mitigation under climate change

Climate change is amplifying Residential Electricity Carbon Emissions (RECE), with aging buildings posing challenges. Due to lack of era-specific assessments of RECE, it still remains unclear whether urban renewal strategies can effectively counteract these climate-driven impacts. Using daily electricity and temperature datasets, we developed temperature-responsive Residential Electricity Carbon footprint (RECF) functions to quantify RECE at building and community’s scale. Aging buildings exhibited 2–4 times higher RECF, while newer buildings contribute >50% of Beijing’s RECE. Higher RECF and compacted conditions led to increased Residential Electricity Carbon Intensity (RECI) in aging communities. Our projections indicated that future climate change will elevate RECE by 6–45% by 2050, with hotspots identified in aging communities inside the 3rd Ring Road and high-rise clusters beyond the 5th Ring Road in Beijing. Among the three evaluated renewal strategies, we also found that Near-Zero Energy Buildings (NZEB) could fully offset the climate-induced increase in RECE in the future. Although requiring a higher initial investment, Ultra-Low Energy Buildings (ULEB) could offer substantial long-term carbon reductions and enhanced climate resilience. These findings can provide an integrated perspective on the interplay among climate conditions, building age, and renewal pathways, offering critical insights for policymaking aimed at facilitating low-carbon and climate-resilient transitions in megacities.