Energy-Saving Renovation of Existing Buildings: Balancing Thermal Performance and Visual Performance—A Case Study of a University Sports Training Annex in Guangzhou

Energy conservation renovation of existing buildings is a crucial aspect of sustainable energy development. This study examines the annex of a university sports training building in Guangzhou, highlighting the conflict between maintaining landscape visibility and mitigating excessive solar radiation and thermal conditions following renovation without external shading. Specifically, the analysis focuses on scenarios where the building’s primary orientation aligns with the region’s unfavorable solar orientation. To address this challenge, five facade optimization strategies are proposed, four of which incorporate external shading solutions: horizontal shading, vertical baffle shading, inclined baffle shading, and a comprehensive shading system. Performance simulations were conducted using Ladybug and Honeybee tools within the Grasshopper platform to evaluate the multi-objective optimization of the building’s thermal and visual performance under energy conservation constraints. The findings demonstrate that an integrated shading system significantly influences both building energy consumption and thermal performance. Notably, the 46° inclined baffle shading scheme proves particularly effective in the Guangzhou context, successfully reducing solar radiation, improving indoor lighting quality, and lowering energy consumption, while minimizing visual obstruction. These results provide valuable insights for developing energy-efficient renovation strategies for similar buildings in the region.