Abstract
External windows and shading systems significantly influence solar radiation control and natural daylighting in building spaces. This study focuses on west-facing dormitory rooms in universities in Kunming, China-spaces particularly prone to solar overexposure-and proposes a fixed external shading design method optimized for solar heat control and daylighting performance. A parametric modeling and simulation approach was adopted, and Pareto-optimal solutions were generated using the Non-dominated Sorting Genetic Algorithm II (NSGA-II). Results indicate that a shading configuration with a panel depth of 0.35 m, spacing of 0.27 m, and an upward horizontal tilt of 7° effectively minimizes seasonal fluctuations in solar heat gain while achieving a reasonable trade-off with daylighting. The Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) was further applied to evaluate and rank the multi-objective solutions. Under equal-weight evaluation, a configuration with a depth of 0.4 m, spacing of 0.57 m, and a 3° vertical tilt facing north ranked highest, indicating a strong balance between thermal control and daylight performance.This study focuses on optimizing the geometric parameters of passive fixed shading components, without addressing adjustable or dynamic systems. The findings offer practical design references and parametric guidance for external shading strategies in west-facing dormitories in Kunming and other regions with similar climatic conditions.