Abstract
<title>Abstract</title> <p>This study investigates the impact of building shape and orientation, including Qibla alignment, on energy consumption and CO₂ emissions across three distinct climatic regions in Egypt: Cairo, Alexandria, and Aswan. A simulation-based methodology was employed to evaluate four building geometrical shapes: square, rectangular, triangular, and circular—under multiple orientation angles. The analysis was conducted under controlled conditions, where building dimensions, material properties, and operational parameters were kept constant to isolate the effects of geometry and orientation. The results demonstrate that building geometry is the dominant factor influencing energy performance, while the orientation plays a secondary level, but a climate-dependent role. Compact geometries consistently exhibited lower energy consumption and emissions, whereas irregular shapes showed higher sensitivity to solar exposure. The impact of orientation increased with climatic severity, reaching its highest levels in hot desert conditions. The Qibla orientation demonstrated stable and acceptable performance across all cases, with only minor increases in energy consumption relative to optimal orientations. The energy penalty remained within approximately 3–7% in Cairo, 3–6% in Alexandria, and below 3% in Aswan. These findings confirm that aligning buildings with the Qibla direction does not significantly compromise energy efficiency when appropriate design strategies are applied. The study highlights the potential for integrating cultural and functional requirements with energy-efficient building design, providing a validated methodological framework for climate-responsive architecture.</p>