The Impact of Architectural Space Layout on Building Energy Performance: Heating and Cooling Demand of Typical Houses in Residential Projects in Sulaymaniyah City

Volume 13 ,Issue 1 ,December 2026 ,Pages 82-97

Authors

Tablo Abdalla 1 ; Amjad Muhammed Ali Qaradaghi 1

1 Department of Architecture Engineering, College of Engineering, University of Sulaimani, Kurdistan Region, Iraq

DOI logo 10.17656/sjes.10232

Keywords

Abstract

Architectural space layout is an important design parameter that affects heating and cooling demand, yet it has received less attention than other design variables, especially in hot-summer Mediterranean climates. This study examines how transforming open-plan layouts into cellular-plan layouts affects the heating and cooling demand of residential buildings in Sulaymaniyah City, Iraq. Three selected single-family houses were modelled using Design Builder/Energy Plus simulation engine. Two scenarios were developed to separate the effects of spatial subdivision. Scenario A tested spatial subdivision while retaining the baseline activity and operational assumptions. Scenario B combined spatial subdivision with realistic functional thermal zoning by assigning room-specific occupancy profiles. Annual heating and cooling loads were simulated under ideal HVAC conditions, followed by a prescribed ventilation-rate sensitivity analysis. Within the three investigated case models the results indicate controlled spatial subdivision produced only small and inconsistent thermal-demand changes under the tested assumptions. Under Scenario B, cellular layouts with function-specific operation reduced whole-building annual heating and cooling demand by 2.50–4.48%, although spatial subdivision was applied only to the ground floor. Heating demand decreased consistently in all three cases, whereas cooling demand changed only slightly, decreasing in two cases and increasing slightly in one. The prescribed ventilation condition further reduced cooling demand in both layouts without changing their relative thermal-demand ranking. Overall, the findings indicate that spatial subdivision alone produced limited thermal effects, whereas subdivision combined with function-specific operation produced larger changes in thermal demand.

References

  1. United Nations Environment Programme (UNEP), Global Status Report for Buildings and Construction 2024/2025: Not just another brick in the wall – The solutions exist. Scaling them will build on progress and cut emissions fast. 2025, Paris: United Nations Environment Programme. https://doi.org/10.59117/20.500.11822/47214
  2. Abbood, A.W., Al-Obaidi, K.M., Awang, H., and Abdul Rahman, A.M., Achieving energy efficiency through industrialized building system for residential buildings in Iraq. International Journal of Sustainable Built Environment, 2015. 4(1):p.78–90. https://doi.org/10.1016/j.ijsbe.2015.02.002
  3. UNDP–LADP, Kaassamani, O., and Ali, A., Iraq Sulaymaneyah-Governorate SEAP 2. 2025.
  4. Olu-Ajayi, R., Alaka, H., Egwim, C., and Grishikashvili, K., Comprehensive Analysis of Influencing Factors on Building Energy Performance and Strategic Insights for Sustainable Development: A Systematic Literature Review. Sustainability, 2024. 16(12): p. 5170. https://doi.org/10.3390/su16125170
  5. Du, T., Space layout and energy performance: Parametric optimisation of space layout for the energy performance of office buildings. A+BE | Architecture and the Built Environment, 2021. 11(15): p. 1–248. https://doi.org/ 10.7480/abe.2021.15.5972
  6. Shahzad, S., Brennan, J., Theodossopoulos, D., Hughes, B., and Calautit, J.K., Energy and comfort in contemporary open plan and traditional personal offices. Applied Energy, 2017. 185(Part 2): p. 1542–1555. https://doi.org/ https://doi.org/10.1016/j.apenergy.2016.02.100
  7. Cao, J., Zhang, H., Savov, A., Hall, D.M., and Dillenburger, B., Energy-aware design: Predicting building performance from layout graphs. Proceedings of the 2022 European Conference on Computing in Construction, 2022: p. 130–137. https://doi.org/10.35490/EC3.2022.210
  8. Abdullah, W.S., and Abdullah, A.A., Genotypical Change of Traditional Houses in Sulaymaniyah City. The Scientific Journal of Cihan University–Sulaimaniya, 2024. 8(1): p. 1–23. https://doi.org/10.25098/8.1.23
  9. Kottek, M., Grieser, J., Beck, C., Rudolf, B., and Rubel, F., World Map of the Köppen-Geiger climate classification updated. Meteorologische Zeitschrift, 2006. 15(3): p. 259–263. https://doi.org/10.1127/0941-2948/2006/0130
  10. Beck, H.E., McVicar, T.R., Vergopolan, N., Berg, A., Lutsko, N.J., Dufour, A., Zeng, Z., Jiang, X., van Dijk, A.I.J.M., and Miralles, D.G., High-resolution (1 km) Köppen-Geiger maps for 1901–2099 based on constrained CMIP6 projections. ScientificData,2023.10:p.724. https://doi.org/10.1038/s41597-023-02549-6
  11. Hillier, B., and Hanson, J., The Social Logic of Space. 1984, Cambridge: Cambridge University Press. https://doi.org/10.1017/CBO9780511597237
  12. Lobos, D., and Donath, D., The problem of space layout in architecture: A survey and reflections. Arquitetura Revista, 2010. 6(2): p. 136–161. https://doi.org/10.4013/arq.2010.62.05
  13. Ching, F.D.K., and Shapiro, I.M., Green Building Illustrated. 2 ed. 2021, Hoboken, NJ: John Wiley & Sons.
  14. Vischer, J.C., Space Meets Status: Designing Workplace Performance. 1 ed. 2005, Oxford: Routledge.
  15. Alfirević, Đ., and Simonović Alfirević, S., Open-plan in Housing Architecture: Origin, Development and Design Approaches for Spatial Integration. Arhitektura i urbanizam, 2016. 43: p. 45–60. https://doi.org/10.5937/a-u0-11551
  16. Gürsel Dino, İ., and Üçoluk, G., Multiobjective Design Optimization of Building Space Layout, Energy, and Daylighting Performance. Journal of Computing in Civil Engineering, 2017. 31(5): p.04017025. https://doi.org/10.1061/(ASCE)CP.1943-5487.0000669
  17. Alfirević, Đ., Simonović Alfirević, S., and Nikolić, S., Impact of internal openness on the sustainability of residential space. Open House International, 2025. 50(5): p. 857–878. https://doi.org/10.1108/OHI-04-2024-0144
  18. Qaradaghi, A.M.A., The effect of rural building types informing the type of traditional courtyard houses in Sulaimaneyah city. Journal of Planner and Development, 2021. 25(2): p. 158–183.
  19. Yuns, M.M., and Qaradaghi, A.M.A., The Impact of Rapid Growth on the Architectural Aspects of Housing Complexes in Sulaymaniyah City. Eurasian Journal of Science and Engineering, 2026. 11(3): p. 339–357. https://doi.org/ 10.23918/eajse.v11i3p22
  20. Al Jarah, S.H., Zhou, B., Abdullah, R.J., Lu, Y., and Yu, W., Urbanization and Urban Sprawl Issues in City Structure: A Case of the Sulaymaniah Iraqi Kurdistan Region. Sustainability, 2019. 11(2): p. 485. https://doi.org/10.3390/su11020485
  21. Ali, L.S., and Qaradaghi, A.M.A., The Effect of Subdivision Regulations on Housing Typologies. Sulaimani Journal for Engineering Sciences, 2023. 10(2): p. 61–77. https://doi.org/10.17656/sjes.10173
  22. CIBSE, Guide F: Energy Efficiency in Buildings. 3 ed. 2012, London: Chartered Institution of Building Services Engineers.
  23. ASHRAE, 2017 ASHRAE Handbook—Fundamentals. SI ed. 2017, Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning Engineers.
  24. Yoshino, H., Hong, T., and Nord, N., IEA EBC Annex 53: Total energy use in buildings—Analysis and evaluation methods. Energy and Buildings,2017.152:p.124–136. https://doi.org/10.1016/j.enbuild.2017.07.038
  25. Elantary, A.R., Energy Consumption Patterns in Residential Buildings: A Comparative Study of Air Conditioning Systems. Yanbu Journal of Engineering and Science, 2025. 22(2): p. 34–47. https://doi.org/10.53370/001c.128314
  26. Istepanian, H.H., Towards Sustainable Energy Efficiency in Iraq. 2020, Amman: Friedrich-Ebert-Stiftung – FES Jordan & Iraq.
  27. Lechner, N., Heating, Cooling, Lighting: Sustainable Design Methods for Architects. 4 ed. 2015, Hoboken, NJ: John Wiley & Sons.
  28. Etheridge, D., and Sandberg, M., Building Ventilation: Theory and Measurement. 1996, Chichester: John Wiley & Sons.
  29. Steemers, K., and Yun, G.Y., Household energy consumption: A study of the role of occupants. Building Research & Information, 2009. 37(5–6):p.625–637. https://doi.org/10.1080/09613210903186661
  30. Albatici, R., and Passerini, F., Bioclimatic design of buildings considering heating requirements in Italian climatic conditions. A simplified approach. Building and Environment, 2011. 46(8): p. 1624–1631. https://doi.org/10.1016/j.buildenv.2011.01.028
  31. Depecker, P., Ménézo, C., Virgone, J., and Lepers, S., Design of buildings shape and energetic consumption. Building and Environment,2001.36(5):p.627–635. https://doi.org/10.1016/S0360-1323(00)00044-5
  32. Ourghi, R., Al-Anzi, A., and Krarti, M., A simplified analysis method to predict the impact of shape on annual energy use for office buildings. Energy Conversion and Management, 2007.48(1):p.300–305. https://doi.org/10.1016/j.enconman.2006.04.011
  33. Goia, F., Search for the optimal window-to-wall ratio in office buildings in different European climates and the implications on total energy saving potential. Solar Energy, 2016. 132: p. 467–492. https://doi.org/10.1016/j.solener.2016.03.031
  34. Tawfeeq, H., and Qaradaghi, A.M.A., Optimising Window-to-Wall Ratio for Enhanced Energy Efficiency and Building Intelligence in Hot Summer Mediterranean Climates. Sustainability, 2024. 16(17): p. 7342. https://doi.org/10.3390/su16177342
  35. Ghisi, E., and Tinker, J.A., An Ideal Window Area concept for energy efficient integration of daylight and artificial light in buildings. Building and Environment, 2005. 40(1): p. 51–61. https://doi.org/10.1016/j.buildenv.2004.04.004
  36. Cook, M.J., Lomas, K.J., and Eppel, H., How do different low energy cooling strategies affect indoor comfort conditions in an office building?. Building and Environment, 2005. 40(2): p. 196–206. https://doi.org/10.1016/j.buildenv.2004.08.008
  37. Szokolay, S.V., Introduction to Architectural Science: The Basis of Sustainable Design. 3 ed. 2014, Abingdon, Oxon: Routledge.
  38. Aldawoud, A., The influence of the atrium geometry on the building energy performance. Energy and Buildings, 2013. 57: p. 1–5. https://doi.org/10.1016/j.enbuild.2012.10.038
  39. Muhaisen, A.S., Shading simulation of the courtyard form in different climatic regions. Building and Environment, 2006. 41(12): p. 1731–1741. https://doi.org/10.1016/j.buildenv.2005.07.016
  40. DeKay, M., and Brown, G.Z., Sun, Wind, and Light: Architectural Design Strategies. 3 ed. 2014, Hoboken, NJ: Wiley.
  41. Latha, H., Patil, S., and Kini, P.G., Influence of architectural space layout and building perimeter on the energy performance of buildings: A systematic literature review. International Journal of Energy and Environmental Engineering, 2023. 14(3): p. 431–474. https://doi.org/ 10.1007/s40095-022-00522-4
  42. U.S. Department of Energy, EnergyPlus™ Version 23.1.0 Documentation: Input Output Reference. 2023, U.S. Department of Energy.
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