An empirical study on life cycle assessment of double-glazed aluminium-clad timber windows

Purpose: Life cycle assessment (LCA) is a useful tool to determine the environmental performance of materials and products. The purpose of this paper is to undertake the LCA of double-glazed aluminium-clad timber windows in order to determine their environmental performance. Design/methodology/approach: The scope of the LCA study covers the production and the use of windows over a 30-year life span. The LCA exercise has been carried out by auditing the materials and processes involved in the making of the windows. Windows production facilities were visited to investigate the respective quantities and embodied energy of the major constituting materials, i.e. timber, aluminium, glass, infill gases and auxiliary components. The main processes involved, i.e. powder coating of aluminium cladding profiles, glazing unit production and window assembly, were also examined. SimaPro software was used to calculate the environmental impacts associated with the windows for three types of glazing infills: Argon (Ar), Krypton (Kr) and Xenon (Xe). Findings: Embodied energy of a standard sized (1.2 m×1.2 m) double-glazed aluminium-clad timber window is found to be 899, 1,402 and 5,400 MJ for Argon (Ar), Krypton (Kr) and Xenon (Xe) infill gases, respectively. It is also found that an Argon-filled window can lose 95,130 kWh of energy resulting into over 37,000 kg of CO2 emissions. Originality/value: Besides carrying value for research community, the findings of this study can help the building and construction industry adopt windows that are energy-efficient and environmentally less burdensome. It can also help the concerned legislative bodied.