Assessment of Window-to-Floor Ratio, Window Geometry, and Placement in Relation to Visual Comfort and Energy Efficiency in North-Facing Facades of Office Buildings in Tehran

Document Type : Original Article

Authors

1 M.Sc. Architectural Engineering with a specialization in Energy, Islamic Azad University, Najafabad Branch. Esfahan

2 Assistant Professor of Climatology Imam Ali Military University, Tehran

10.22059/ses.2025.386807.1109

Abstract

Windows serve as a critical architectural element for channeling daylight into interior spaces. When designed in alignment with functional requirements, temporal patterns, and climatic conditions, they can transform daylight into a primary lighting source, enhancing occupants' visual comfort while significantly reducing energy demand for artificial lighting and thermal regulation. This study aims to evaluate window design parameters—including geometry, positioning, and Window-to-Floor Ratio (WFR)—through the lens of visual comfort, and subsequently analyze their impact on energy efficiency in north-facing façades of Tehran’s office buildings. Using Design Builder software, parametric modeling and simulation of multiple scenarios were conducted to optimize window configurations. Findings reveal that WFR, window shape, and placement directly influence indoor illuminance levels. Specifically, horizontally oriented rectangular windows (aspect ratio 1:1.5) with a WFR of 20%, positioned in the upper section of the façade, emerge as an optimal solution for balancing daylight provision and energy performance in Tehran’s north-oriented office buildings.

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References

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Journal of sustainable Energy Systems
Volume 4, Issue 3
July 2025
Pages 251-265

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