A comparative LCA of external wall assemblies in context of Iranian market: considering embodied and operational energy through BIM application.

Abstract

Building envelopes have a critical role in the sustainability of the construction sector. The goals of the current research are assessing the environmental impacts of typical exterior wall assemblies and presenting the best Iranian market option through taking account of both embodied and operational energy. Autodesk Green Building Studio (GBS) is used to determine the operating loads of each wall. Simapro, a life cycle assessment software, is applied for managing data on environmental impacts. The derived results demonstrate that human health is the most severe damage category for all the analyzed walls. Also, the end-of-life stage's environmental impact is insignificant compared to the production and use stages. Reducing carbon emissions has the highest priority, such that replacing 1 m2 of masonry brick wall (the worst option) with prefabricated extruded polystyrene (XPS) drywall (the best option) can result in saving 1257.85 kgCO2eq. The operational phase of the studied walls has a wide range of environmental impacts. Prefabricated Knauf drywall as well as prefabricated XPS drywall consumes less energy for the operating phase mainly due to providing sufficient quantity of isolations that leads to the better total environmental performance. In conclusion, it should be noted that the thermal performance of building materials should be given more attention.