Evaluating The Environmental Performance Of Stick Curtain Wall Systems

The construction industry is one of the greatest sources of pollution, where 39% of global energy-related carbon emissions are attributed to buildings’ direct and indirect emissions (UNEP-SBCI 2017). Facades have a high influence on energy consumption during the building life cycle and, consequently, contribute to buildings' CO2 equivalent emissions (CO2e). This paper examines the influence of varying design parameters to enhance the environmental performance of stick curtain wall systems. The environmental performance is determined by measuring the curtain wall system's contribution to the building's operational energy consumption and assessing its global warming potential throughout its whole life cycle. The curtain wall contribution to building operational energy consumption in terms of heating and cooling demands (kWh/year) was calculated through an energetic analysis using EVEBI Pro software. A whole life cycle assessment (WLCA) from cradle to cradle was carried out to define the global warming potential (KgCO2e) using OneClick LCA software. The first design parameter is the glass type and thickness, including the existing 56mm TGU and three other variants, 44mm TGU, 27mm DGU, and 24mm DGU. The second design parameter is the profile material and system, including the existing profile VISS 60 steel and two variants, FWS 60 aluminium and AOC 60 timber. The results indicate that reducing the curtain wall glass thickness from 56mm to 44mm would reduce the embodied carbon emissions almost by half and slightly impact the operational energy consumption related to heating and cooling demands. Also, using 27mm DGU instead of 24mm DGU would significantly reduce the curtain wall’s WLCA. Regarding the other parameter, the comparison shows that the baseline VISS 60 steel profile system has the lowest global warming potential, followed by the AOC 60 timber and FWS 60 Alu systems.