Assessing the Impact of Window Size, Placement on the wall, and Glazing on Visual Comfort in the Learning Spaces of Elementary Schools in Adama City, Ethiopia.

Abstract

This study evaluates the impact of window design parameters (size, placement on walls, and glazing type) on visual comfort in elementary school learning spaces across Adama City, Ethiopia's, targeting a population of 181 elementary schools (64 government and 117 private) with purposive sampling of four representative schools (ASTU Community, Awash Academy, Nafyad, and Geda Michile) encompassing 214 students across classrooms with varying orientations (north, south, east, west). Employing a mixed-methods approach, quantitative data collection utilized NIST-calibrated lux meters (±3% accuracy) for illuminance measurements (56 point grid at 0.75m working plane), thermal cameras (±2°C) for temperature monitoring, and HDR imaging for glare analysis, while qualitative data gathered through structured questionnaires (5-point Likert scales) and behavioral observations assessed occupant perceptions. Computational simulations using Autodesk Ecotect analyzed climate-based daylight metrics and glare probability (DGP), with statistical analysis including Pearson correlations (r=0.82 between illuminance and satisfaction) and multiple regression to evaluate design-performance relationships. Key findings revealed 76.6% of classrooms failed to meet the 300 lux standard (range: 81-2,440 lux), with 68.7% exhibiting glare issues (DGP>0.35), particularly in southwest facing rooms experiencing afternoon solar exposure, while northeast orientations maintained optimal 300-500 lux; gender disparities showed female students reported 5-10% greater glare sensitivity (p<0.05). The study identifies critical gaps in Ethiopia's EBCS 12 standards and proposes evidence-based, climate-responsive solutions: optimized 25-30% window-to-wall ratios with orientation-specific shading, high-reflectance surfaces (70-85% ceilings, 50-70% walls), and low-SHGC glazing (≤0.4), while acknowledging limitations including the 35-day temporal scope and recommending future research on gender-inclusive design frameworks and cost-benefit analyses of retrofitting strategies for Ethiopia's diverse microclimates, ultimately providing policymakers and architects with actionable passive design strategies to enhance learning environments through integrated daylight optimization and thermal comfort solutions.