Evaluating the Effectiveness of Bioclimatic Design Strategies in Warm-Humid Institutional Buildings (Published)
Warm-humid climatic zones present enduring challenges to achieving indoor thermal comfort in naturally ventilated institutional buildings. Despite growing global interest in bioclimatic architecture, empirical assessments of passive design effectiveness in public university buildings across tropical Sub-Saharan Africa remain sparse. This study evaluates the effectiveness of five core bioclimatic design strategies (building orientation and layout, shading devices, opening and ventilation systems, landscaping, and internal courtyards) in 62 public university buildings constructed between 2012 and 2023 across six state capitals in Southwest Nigeria. A mixed-methods approach integrated objective bioclimatic audits, Evans Comfort Scale and Mahoney Table analyses, indoor environmental measurements using a calibrated Kestrel 4500 Weather Meter, and subjective post-occupancy evaluations from 374 validated respondents. Findings reveal significant deficiencies in the implementation of all five strategy categories. Opening and ventilation systems registered the highest importance index (II = 4.17) among occupants, followed by landscaping (II = 3.67), courtyards (II = 3.34), orientation/layout (II = 3.21), and shading devices (II = 3.20). Multivariable ordinal logistic regression identified perceived indoor temperature (β = 1.58; OR = 4.86; p < .001) and air velocity (β = 0.94; OR = 2.56; p = .002) as the strongest physiological predictors of thermal comfort satisfaction. Building openings exerted the greatest design-based influence on comfort outcomes (β = 1.42; OR = 4.14; p < .001). Approximately 69.8% of respondents reported thermal discomfort, with afternoon conditions (12:00–18:00 h) rated most uncomfortable by 59.4% of occupants. The study establishes location-specific thermal comfort indices and bioclimatic design benchmarks for six Nigerian cities, contributing empirical data toward the revision of the Nigeria Building Energy Efficiency Code (N-BEEC) and advocating for the integration of adaptive passive design guidelines in institutional building policy.
Keywords: Natural Ventilation, Nigeria, Post Occupancy Evaluation, Thermal Comfort, bioclimatic design, courtyard design, institutional buildings, passive cooling, shading devices, warm-humid climate