Response Surface Methodology (RSM) and desirability functions were employed
in a case study to optimize the thermal and daylight performance of a
computational model of a tropical housing typology. Specifically, this approach
simultaneously optimized Indoor Overheating Hours (IOH) and Useful Daylight
Illuminance (UDI) metrics through an Overall Desirability (D). The lack of
significant association between IOH and other annual daylight metrics enabled a
focused optimization of IOH and UDI. Each response required only 138 simulation
runs (~30 hours for 276 runs) to determine the optimal values for passive
strategies: window-to-wall ratio (WWR) and roof overhang depth across four
orientations, totalling eight factors. First, initial screening based on
2V8−2 fractional factorial design, identified four key factors using
stepwise and Lasso regression, narrowed down to three: roof overhang depth on
the south and west, WWR on the west, and WWR on the south. Then, RSM
optimization yielded an optimal solution (roof overhang: 3.78 meters, west WWR:
3.76%, south WWR: 29.3%) with a D of 0.625 (IOH: 8.33%, UDI: 79.67%). Finally,
robustness analysis with 1,000 bootstrap replications provided 95% confidence
intervals for the optimal values. This study optimally balances thermal comfort
and daylight with few experiments using a computationally-efficient
multi-objective approach.