INDOOR AIR QUALITY AND THERMAL ENVIRONMENT ASSESSMENT OF SOUTH-WEST NIGERIAN HOMES WITH DIFFERENT BUILDING FABRICS

Abstract

This study investigates the impact of building fabrics on indoor air quality (IAQ) and thermal comfort in residential buildings across South-West Nigeria’s hot-humid climate. Through a mixed-methods approach, 102 residents from six states (Lagos, Ogun, Ondo, Oyo, Osun, Ekiti) were surveyed to assess perceptions of IAQ, thermal comfort, and adaptive behaviors. Building materials were categorized by wall types (sandcrete blocks, mud/brick, wood) and roof types (aluminium/zinc, thatch, concrete, slate). Results revealed significant disparities in environmental performance: mud/brick walls outperformed sandcrete and wood in air freshness (mean = 4.05 vs. 3.41) and dry-season thermal comfort (mean = 4.18 vs. 3.45), while thatch/slate roofs excelled in reducing stuffiness and enhancing comfort compared to aluminium/zinc. Statistical analyses (Kruskal-Wallis tests, MANOVA) confirmed material-driven differences in IAQ/thermal indicators (*p* < 0.001). Over 72% of households relied heavily on mechanical cooling (>13 hours/day), with roofing material significantly predicting fan usage (χ² = 15.32, *p* = 0.018). The study concludes that traditional materials (mud/brick, thatch/slate) optimize passive regulation in tropical climates, reducing energy dependency. Recommendations include prioritizing adaptive materials in design, reforming building codes, and promoting low-cost retrofits to enhance occupant health and sustainability.