Comparative analysis of wall materials for their operational energy performance in urban mid-rise residential buildings: a simulation-based study in Istanbul

As urbanization continues to drive a substantial share of global energy consumption and carbon emissions, mitigating the environmental footprint of residential buildings in urban areas becomes imperative. Although there are numerous studies focused on designing low embodied-carbon construction materials to mitigate the carbon footprint of the construction industry, there is a significant gap regarding the applications and operational performance of these alternative materials in urban environments, which results in low demand for them in the current construction market. This study focuses on evaluating the operational performance of low embodied-carbon alternative materials when they are used in mid-rise residential building envelopes in urban environments, with a particular emphasis on the energy consumption of buildings for achieving occupant thermal comfort. The study commences with a literature review of low embodied-carbon materials suitable as an infill material for exterior walls, followed by simulation-based assessments using Rhino-Grasshopper and OpenStudio software to compare the operational energy performance of the alternative materials against the conventional materials in Istanbul, Turkey. The results present the operational performance of the materials considering the local factors such as urban morphology and urban weather of the case study site in Istanbul. They also highlight possible improvements needed for some alternative materials to achieve or exceed the operational performance of conventional envelope materials. Hence, this research provides insights for architects, policymakers, and construction industry professionals by identifying materials with significant sustainability potential for urban environments and emphasizing the need for context-specific adaptations of them. It addresses a critical gap in the literature on the operational phase of low-embodied carbon construction materials and developing low-carbon residential architecture in urban environments.