Parametric Analysis of Baffle External Shading for Sustainable Building Design: Daylighting and Thermal Performance Optimization in Cold Climate Regions of China

Building energy efficiency is critical for achieving sustainable development goals, particularly in low- and middle-income countries where rapid urbanization drives energy demand growth. This study presents a parametric analysis of baffle external shading for a west-facing educational building in Xianyang, a cold climate region of China, integrating daylighting performance and indoor thermal regulation. Using Ladybug and Honeybee plugins in Grasshopper, three key shading parameters—shading characteristic value (x), baffle angle (δ), and baffle arc (θ)—were systematically varied to evaluate their effects on solar radiation distribution, useful daylight illuminance (UDI), and indoor temperature. Results indicate that vertical louvers with x ≥ 0.50 and δ = 45° in the west orientation reduce ground radiation by up to 47% and lower average indoor temperature by approximately 2 °C under free-running conditions, while UDI reaches 81.3% of occupied hours (6.5 h/d) with optimized shading in cold regions. The baffle arc (θ) has negligible impact. These findings provide actionable design guidelines for cost-effective passive cooling, requiring less than 2% of total building investment with simulated annual energy savings of 10.5% for the case-study classroom (cooling and heating terms only), supporting China’s “Dual Carbon” goals and broader sustainable urban development targets.