International Journal of Urban Management and Energy Sustainability

International Journal of Urban Management and Energy Sustainability

Impact of Thermal Insulation on Energy Behavior of Residential Building Envelopes (Case Study: District 15 of Tehran city, Iran)

Articles in Press

Document Type : Case Study

Authors
Reza Salimi Gargari 1
Majid Mofidi Shemirani 2
Haniyeh Sanaieian 3
1 Ph. D. candidate, Department of Architecture, Science and Research Branch, Islamic Azad University, Tehran, Iran.
2 Assistant Professor, Department of Architecture, Science and Research Branch, Islamic Azad University, Tehran, Iran
3 Assistant Professor, Department of Architecture, Iran University of Science and Technology, Tehran, Iran
10.22034/ijumes.2025.2060021.1311
Abstract
Buildings account for approximately 40% of global energy consumption, with poorly performing building envelopes significantly contributing to unsustainable energy demands. This issue is particularly critical in semi-arid climates such as Tehran, where extreme seasonal temperatures result in high residential energy use for heating and cooling. This study aims to address Tehran''s energy efficiency challenges by optimizing the insulation thickness of residential façades in District 15. Using validated simulations conducted in DesignBuilder and informed by GIS data and on-site measurements, three scenarios of rock wool insulation 3 cm, 5 cm, and 7 cm were modeled and analyzed. The results demonstrate that a 7 cm insulation layer achieves the lowest energy consumption (Cooling: 13.01 kWh/m²; Heating: 306.7 kWh/m²), while the 5 cm option represents the most cost-effective solution, yielding an annual energy savings of approximately 2,500 kWh/m². Furthermore, the study confirms that compliance with Iran’s National Building Regulations, specifically Topic 19, leads to an 18.7% reduction in natural gas consumption. These findings offer valuable insights for urban energy policy, particularly in arid and semi-arid environments. Future research should investigate the integration of phase-change materials and conduct multi-climatic simulations to generalize the applicability of the proposed optimization model

Graphical Abstract

Impact of Thermal Insulation on Energy Behavior of Residential Building Envelopes (Case Study: District 15 of Tehran city, Iran)

Highlights

  • Building façades account for 40% of global energy consumption, with insulation being crucial for regulating thermal exchange.
  • The integration of software simulation (DesignBuilder) and GIS analysis enables realistic modeling of thermal behavior.
  • Increasing insulation thickness from 5 cm to 7 cm results in a reduction of 2.05 kW-h/m² in heating energy consumption.
  • The choice of 5 cm insulation over 7 cm is driven by cost-benefit considerations, despite the latter''s superior thermal performance.
  • Adhering to national standards (topic 19) is essential for achieving energy savings and promoting environmental sustainability.

Keywords
Building envelope
Thermal insulation optimization
Energy efficiency
Residential buildings
Tehran climate
Insulation thickness economics
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International Journal of Urban Management and Energy Sustainability

Articles in Press, Accepted Manuscript
Available Online from 15 September 2025

  • Receive Date 07 May 2025
  • Revise Date 01 September 2025
  • Accept Date 15 September 2025