Assessment of Climate Change Impact in Tropical Buildings: Sensitivity Analysis of Light Shelf and Building Design Parameters for Daylighting and Thermal Balance

Climate change may lead to more intense sunlight in tropical regions, potentially increasing the daylight available for buildings. While this can enhance natural lighting inside buildings, it may also exacerbate issues such as glare and overheating if not properly managed through shading devices and glazing treatments. Nevertheless, common strategies to mitigate heat gain and glare such as shades and blinds often obstruct natural light, necessitating increased reliance on artificial lighting. The conflicting interplay between daylighting and thermal performance can undermine building performance if not carefully considered. Existing research on the influence of key design parameters in tropical climates tends to focus predominantly on heat gain mitigation, neglecting other aspects. This study addresses these gaps by examining the holistic daylighting and thermal energy performance of buildings to develop optimised façade and resilient designs against climate change. The investigation encompasses an analysis of 11 design parameters of light shelves and building characteristics that are critical during the initial design stage. Global sensitivity analysis (GSA) is employed to identify the most influential design parameters affecting useful daylight illuminance, uniformity ratio, cooling energy, and solar gain energy. A case study involving double-story terrace houses in Malaysia is employed, with analyses conducted for the present and future climates of three Malaysian cities (Kuala Lumpur, Bayan Lepas, and Kota Bahru). The findings reveal that, across all three cities, glazing transmittance is the most influential parameter for daylighting performance, while room depth assumes primary significance for thermal performance. Although the relative ranking of parameters remains consistent between present and future climates, their magnitudes differ. In summary, this paper gives designers insights into the critical design parameters essential for achieving a balanced and resilient daylight-thermal design in tropical climates at the initial stages of the design process.