Bioclimatic optimization for medium density housing in Jakarta transit oriented developments through microclimate simulation

Rapid urbanization and the expansion of Transit-Oriented Development (TOD) in tropical megacities often overlook the microclimatic experience of pedestrians, leading to severe Urban Heat Island (UHI) effects and thermal discomfort. This study introduces and computationally evaluates the Bioclimatic Transit-Infill Housing (BTIH) concept, a medium-density housing model with minimum parking, located at the Blok A Mass Rapid Transit (MRT) station in Jakarta, Indonesia. By reallocating space from parking infrastructure to communal green areas and passive design, the proposed model seeks to improve thermal comfort for last-mile commuters. This study utilized Autodesk Forma to simulate critical microclimate parameters, including sun exposure, wind aerodynamics, and acoustic propagation, cross-referenced with calculated Wet-Bulb Globe Temperature (WBGT) and Universal Thermal Climate Index (UTCI) metrics. Baseline analysis indicated extreme thermal stress (UTCI reaching 39 °C) and stagnant wind velocity (< 1 m/s). Conversely, predictive simulations of the BTIH suggest that subtractive geometric massing optimizes wind flow within the layout. Furthermore, the podium functions as an architectural shading facade, with theoretical WBGT values tracking near 29.45 °C, while acoustic strategies reduced rail noise to below the 55 dB residential threshold. This study, operating within the boundary assumptions and default settings of Autodesk Forma and its calculations, provides an early-stage simulation-based design evaluation rather than a field-validated environmental assessment. By acknowledging that these predictive results are not calibrated against on-site meteorological data or field measurements, this research demonstrates that integrating quantitative building physics into early-stage massing offers a comparative relative framework for localized microclimatic mitigation.