Field-Based Assessment of Vegetation Structure and Configuration (VSC) For Thermal Regulation in Tropical Residential Environments

Abstract

The increase of Urban Heat Islands (UHI) in tropical regions such as Malaysia has exacerbated thermal discomfort in residential areas due to diminished vegetation and inadequate landscape planning. Although vegetation is recognized for its passive cooling benefits, the precise influence of Vegetation Structure and Configuration (VSC) on microclimate regulation across different housing layouts is insufficiently investigated. This study examines the influence of VSC on thermal regulation in two low-rise residential typologies in Perak, Malaysia labelled as a Structured Landscape House (SLH) and a Semi-Structured Landscape House (SSLH). Field measurements were executed over five days in the wet season (October to November), documenting air temperature (oC), relative humidity (RH), and wind velocity (m/s) both indoors and outdoors using two units Thermal Microclimate Monitoring System (HD32.1) for outdoor measurements and Indoor Air Monitoring System (HD37AB1347) for indoors. The findings demonstrate that the SLH, distinguished by its dense, multi-layered vegetation and strategic configurations, consistently surpassed the SSLH in regulating indoor temperatures (30.55°C compared to 31.41°C), decreasing humidity levels (62.39% versus 72.03%), and stabilizing air velocity (0.01 m/s average for both, with enhanced consistency in SLH). These findings confirm that well-organized and strategically positioned vegetation substantially improves residential thermal comfort, underscoring the importance of VSC as a passive design approach in tropical urban planning.