Urban microclimate plays a critical role in sustainable aging-friendly community design, yet the impacts of small-scale morphological modifications like elevator additions remain underexplored. This study innovatively integrates multi-domain simulation approaches to address this gap, employing GBSware’s coupled modules (TERA for thermal environment, SUN for solar irradiation, VENT for wind field analysis, and SEDU for acoustic modeling) to holistically assess the hidden effects of elevator retrofitting in high-density residential areas. Simulations reveal that elevator additions reduce urban heat island intensity by 0.38–0.67 °C through enhanced shading effects, while demonstrating minimal impacts on wind ventilation patterns. However, the intervention decreases facade solar irradiation by 10%–20% on affected elevations and elevates A-weighted sound pressure levels by 10–25 dB during operation. These findings provide new insights into the paradoxical microclimate impacts of vertical transportation infrastructure in aging communities, advancing the methodology for evaluating small-scale urban form modifications.