Examining the Impact of Window-to-Wall Ratio on the Optimization of Window Placement and Dimensions for Daylight Improvement in Office Buildings (Case Study: Tehran Climate)

Subject Areas : City architect

Arezoo Malek ¹ , Roozbeh Naghshineh ² , Alireza Karimpour ³ , Leila Zare ⁴

1 - Department of Architecture, West Tehran Branch, Islamic Azad University, Tehran, Iran
2 -
3 - Department of Architecture, South Tehran Branch, Islamic Azad University, Tehran, Iran
4 - Department of Architecture, West Tehran Branch, Islamic Azad University, Tehran, Iran

Received: 2025-06-07 Accepted : 2025-09-21 Published : 2025-09-22

Keywords: Advanced Simulation, Window-to-Wall Ratio Optimization, Daylight, Office Building, Hot & Dry Climate,

Abstract :

With the expansion of urbanization and increasing dependence on artificial lighting systems, the role of façade design in leveraging natural daylight has gained critical importance. In regions with high solar exposure, achieving a balance between maximizing daylight use and minimizing glare presents a major challenge in sustainable architecture. The window-to-wall ratio (WWR), as a key determinant of daylight performance, must be carefully optimized in relation to the size and placement of openings. This study investigates the effect of WWR on the optimal dimensions and locations of openings to enhance daylight performance in an office building located in Tehran’s climatic context. The methodology combines literature review with advanced daylight simulations using parametric tools such as Grasshopper, Honeybee, Ladybug, and the Wallacei optimization plugin. Key parameters include WWR, window height, sill level, and the number of windows, with a focus on optimizing useful daylight illuminance (UDI) while reducing both insufficient and excessive daylight levels. Results indicate that at lower WWRs, increasing both the number and height of openings improves daylight distribution. However, higher WWRs significantly elevate the risk of glare. A WWR range of 40% to 50%, especially at 42%, was found to offer the most effective balance between daylight access and visual comfort. An integrated design approach, incorporating sustainable architectural technologies aligned with local climatic needs, enhances energy performance and spatial quality. This strategy supports the development of climate-responsive and environmentally conscious architecture.

References:

جاوید, پریسا، نیک‌قدم, نیلوفر، کریم‌پور, علیرضا و صابرنژاد, ژاله . (1404). ارزیابی سیستماتیک علم‌سنجی در روش‌های بهینه‌سازی انرژی در ساختمان. باغ نظر22(142).41-56.. doi: 10.22034/bagh.2025.490974.5717
رفیعیان، مجتبی، فرهادی‌پور، احمد، رصدخانه شهری تهران و همکاران (1396). رصد وضعیت شهرسازی تهران: نظام قطعه‌بندی و کاربری زمین. تهران: سازمان فناوری اطلاعات و ارتباطات شهرداری تهران.
شادان ،مسعود، زمانی، زهرا. (۱۴۰۴)، بهبود کیفیت نور روز کلاس درس در عرض های مختلف جغرافیایی از طریق طاقچه نوری. نقش جهان - مطالعات نظری و فناوری های نوین معماری و شهرسازی.; ۱۵ (۲) :۱-۱۶
شهرداری تهران. (۱۳۹۳). معرفی شهر تهران. شرایط اقلیمی. بازیابی 20 بهمن، ۱۳۹۳، ازhttps://www.tehran.ir/Default aspx?tabid=117
صدری، سید علی اکبر، کابلی، محمد هادی، میرزا رضایی، میترا و سلیمانی، محمدرضا،1402،تحلیل روش ها و رویکرد های تولید چیدمان های خودکار فضایی، معمار شهر، 2(7)/117-90. https://civilica.com/doc/1861791
قیومی ایلخچی, گلناز , قره‌بگلو, مینو و ملکی, آیدا . (1404). تأثیر نور روز بر واکنش‌های احساسی در فضاهای سکونتی شهر تبریز. باغ نظر. 22(142) . 71-82 . doi: 10.22034/bagh.2025.488090.5705
کریم پور، علیرضا و دیبا، داراب و اعتصام، ایرج،1396،تحلیل تأثیر آفتاب گیرهای داخلی بر مصرف انرژی با استفاده از مدل‌های شبیه سازی (مطالعه موردی: واحد مسکونی درتهران)،https://civilica.com/doc/980082
معروفی، ندا، مهدوی نژاد، محمدجواد و مرادی نسب، حسین .(1401). نوردوستی در ساختمان های آموزشی؛ نمونه مطالعاتی: بهینه سازی جداره های جنوبی کلاس درس در شهر سمنان. معماری اقلیم گرم و خشک. (16)10، 181-164. doi: 10.22034/ahdc.2023.18776.1668
مقررات ملی ساختمان، مبحث نوزده: صرفه‌جویی در مصرف انرژی، ویرایش چهارم،تهران:وزارت راه و شهرسازی،1399، ص 51.
مقررات ملی ساختمان، مبحث نوزده: صرفه‌جویی در مصرف انرژی، ویرایش چهارم،تهران:وزارت راه و شهرسازی،1399، ص 152.
مهربان سه‌گنبد، زهرا، جاویدی‌نژاد، مهرداد، و تیزقلم زنوزی، سعید. (1402). همبستگی شاخص‌های تکنولوژی با ارتقاء بهره‌وری و کاهش مصرف انرژی در مسکن‌های اقلیمی. معمار شهر3(10).
Al-Mowallad, Ezzaddeen & Huang, Xianfeng & Lu, Zhen & Li, Xiaofan & Wu, Kaiwen & Zhu, Zhirui & Liu, Guohuan. (2024). Assessment and Improvement of Daylighting Quality in Classrooms with Double-Side Windows. Buildings. 14. 3501. 10.3390/buildings14113501.
Andarini, R., 2014. The role of building thermal simulation for energy efficient building design. Energy Procedia 47, 217–226.
Bournas, Iason. (2020). Daylight compliance of residential spaces: Comparison of different performance criteria and association with room geometry and urban density. Building and Environment. 185. 107276. 10.1016/j.buildenv.2020.107276.
Brzezicki, M. An Evaluation of Useful Daylight Illuminance in an Office Room with a Light Shelf and Translucent Ceiling at 51◦ N. Buildings 2021, 11, 494. https:/ /doi.org/10.3390/buildings11110494.
Canestrino, Giuseppe & Miraglia, Simone & Perri, Giuseppe & Lucente, Roberta. (2021). Parametric Strategies in an Architectural Design Workshop. 511-522. 10.5151/sigradi2021-115.
Carlucci, S., Causone, F., Derosa, F., Pagliano, L., 2015. A review of indices for assessing visual comfort with a view to their use in optimization processes to support building integrated design. Renew. Sustain. Energy Rev. 47, 1016–1033.
Dreza Saremi, H., Khodabakhshi, S., & Khalaghdoost, M. (2016). Applying genetic algorithms in architecture. Specialty journal of Engineering and Applied Science, Vol, 1 (1): 1-19
Fang, Y., Cho, S., 2019. Design optimization of building geometry and fenestration for daylighting and energy performance. Sol. Energy 191, 7–18.
Horvat, Marko & Luca, Bruno & Khris, Sami & Raffaele, Lorenzo. (2019). Aerodynamic shape optimization of barriers for windblown sand mitigation using CFD analysis. Journal of Wind Engineering and Industrial Aerodynamics. 197. 10.1016/j.jweia.2019.104058.
Konis, Kyle & Gamas, Alejandro & Kensek, Karen. (2016). Passive performance and building form: An optimization framework for early-stage design support. Solar Energy. 125. 161-179. 10.1016/j.solener.2015.12.020.
Kӧster, H., Daylighting Controls, Performance and Global Impacts, Encyclopaedia of Sustainability Science and Technology, Springer New York, 2012, pp. 2846-2896.
M Makki, M Showkatbakhsh, Y Song - Online]. Tratto da www. wallacei. com, 2019.
Machairas, Vasileios & Tsangrassoulis, Aris & Axarli, Kleo. (2014). Algorithms for optimization of building design: A review. Renewable and Sustainable Energy Reviews. 31. 101–112. 10.1016/j.rser.2013.11.036.
Marcin, Brzezicki. (2021). An Evaluation of Useful Daylight Illuminance in an Office Room with a Light Shelf and Translucent Ceiling at 51° N. Buildings. 11. 494. 10.3390/buildings11110494.
Mardaljevic, J., Heschong, L., and Lee, E. 2009. Daylight metrics and energy savings. Lighting Research and Technology, 41(3):261–283.
Mardaljevic, John & Andersen, Marilyne & Roy, Nicolas & Christoffersen, Jens. (2012). Daylighting metrics: is there a relation between useful daylight illuminance and daylight glare probability..
Motamedi, S., Liedl, P., 2017. Integrative algorithm to optimize skylights considering fully impacts of daylight on energy. Energy Build. 138, 655–665.
Reinhart, C., Rakha, T., & Weissman, D. (2014). Predicting the Daylit Area-a Comparison of Students Assessments and Simulations At Eleven Schools of Architecture. Leukos, 10(4), 193-206. DOI: 10.1080/15502724.2014.929007
Reinhart, Christoph, Visual Comfort and Occupant Behaviour, MIT Open Course Ware, 2012, Available: http://ocw.mit.edu [accessed 25.07.2016].
Roudsari, M.S., Pak, M., Smith, A., 2013. Ladybug: a parametric environmental plugin for grasshopper to help designers create an environmentally-conscious design. In: Proceedings of the 13th International IBPSA Conference Held in Lyon, France Aug.
Stephan, A., Crawford, R.H., De Myttenaere, K., 2011. Towards a more holistic approach to reducing the energy demand of dwellings. Procedia Eng. 21, 1033–1041.
Toutou, A., Fikry, M., Mohamed, W., 2018. The parametric based optimization framework daylighting and energy performance in residential buildings in hot arid zone. Alexandria Eng. J.57 (4), 3595–3608.
Vaisi, S., & Kharvari, F. (2019). Evaluation of daylight regulations in buildings using daylight factor analysis method by Radiance. Energy for Sustainable Development, 49, 75-84. https://doi.org/10.1016/j.esd.2019.02.002
Van Bommel, W.J.M. & Beld, G.J. Van den Lighting for work: a review of visual and biological effects, Lighting Research and Technology, 2004, Vol. 36 (4) pp. 255-266.