Using SimaPro software, this study, published at the end of March, identifies the cradle-to-grave environmental impacts of wood, modified wood and aluminium-clad windows and provides a comparison with PVC-U.
It provides evidence that wood is the most sustainable choice, showing that PVC-U windows have roughly four times the CO2e impact of wood windows and roughly twice the impact of modified wood or aluminium-clad windows.
Conducted by Dr Gillian Menzies of the Institute for Building and Urban Design, Heriot Watt University, Edinburgh, it is the final stage of a suite of studies that includes Service Life Planning and Whole Life Costing.
For the first time, specifiers are able to use authoritative data to compare window types across durability, value and environmental impact.
The study examines different exposure conditions and maintenance regimes. It finds that wood windows made to Wood Window Alliance standards have an expected service life of around 60 years – approximately twice as long as PVC-U - while modified wood and aluminium-clad windows will last even longer.
Although PVC-U is cheaper over 20 years, wood windows offer better value over 30 years or more, even allowing for maintenance; while modified wood and aluminium-clad windows offer better value in severe exposure conditions (coastal areas or high-rise).
For more information, visit www.woodwindowalliance.com