The characteristics of the frame materials have significant impacts on the properties of a window. A window itself plays a crucial role in determining the overall energy performance of the building. This article analyses four different frame types; aluminium, aluminium-clad timber, Polyvinyl chloride (PVC) and timber make, from the sustainability perspective. These frame types have been studied on various parameters such as; environmental impacts during production/extraction of frame materials and disposal of frames; embodied energy, durability and service life; and maintenance and repair of frames. A price comparison and market scenario has also been discussed. It has been found that timber- and aluminium-clad timber windows are sustainable products due to their environment-friendly characteristics i.e., low embodied energy, low environmental impacts, better durability and longer service life. While aluminium and PVC frames have high values of embodied energy and associated environmental impacts.

Practical application: In the present sustainability-conscious age, the window industry is emphasising how to enhance the energy and environmental performance of their products. This article will be of interest not only to modern window manufacturers but also to customers as it addresses the key sustainability features of windows, i.e., energy and environmental performance, durability and service life, and maintenance and life cycle costing.