Implementing sustainable zero energy building standards in Iraq energy efficiency measures

• Comprehensive simulation-based study to optimize the building envelope for nZEBs in Iraq's extreme hot-arid climate. • Wall insulation slashes cooling energy by up to 62%, a paramount gain for a cooling-dominated region. • A 10% window-to-wall ratio (WWR) and north orientation form the optimal configuration to minimize solar gain. • Provides climate-specific performance data crucial for adapting international sustainability standards to the Iraqi context. The study deals with the improvement of energy efficiency, focusing on the realization of zero-energy buildings. This paper aims at the building envelope in Iraq, putting into consideration the main aspects related to energy consumption and thermal comfort. The research has pinpointed various shortcomings of the current Iraqi building material, which include external walls and single-pane windows that have poor thermal insulation and hence contribute to higher energy wastage in Iraq's hot climate. It surveys four types of external wall structures and suggests advanced insulation materials such as aerated concrete, polyurethane, and mineral wool be considered. Computer modeling using Design Builder and mathematical simulations revealed a surprising increase in thermal resistance when those materials were combined, reducing heating and cooling loads. Similarly, thermally optimized double and triple glazing using insulating gases like argon and xenon was tested in a way that has minimum energy transfer. Substantial gains in energy efficiency were achieved compared with the present single-glazed window. Energy performance related to different window-to-wall ratios and building orientations is also analyzed in this regard. A lesser WWR reduces solar heat gain, while a northern orientation reduces the total energy consumption because of reduced solar exposure. Optimal configurations were pointed out by a multi-objective algorithm: the best WWR is 10%, and north orientation is optimum in terms of energy efficiency in the Iraq climate. These findings call for the integration of advanced thermal insulation materials, innovative window technologies, and optimized design parameters into the building design to provide higher energy efficiency with reduced carbon footprints from Iraqi buildings.