The study, conducted by Dr Gillian Menzies at Heriot Watt University, builds on earlier work by Imperial College London and sets a new standard for the whole life analysis of windows.
For the first time, the industry can use authoritative data to compare the durability, value and environmental impacts of different window frame materials.
The report concludes that, in normal conditions, timber window frames made to WWA specifications offer the best value, with a service life of approximately 56-65 years, and are the most environmentally-friendly choice.
For severe exposure, such as high-rise buildings or coastal developments, aluminium-clad and modified timber frames can provide even better value.
While the initial cost of PVCu windows is the lowest, all timber-based options offer better long-term value. PVCu window frames are rated as having a planned service life of 25-35 years.
The whole life snalysis features a life cycle assessment which shows all timber-based window frames have a Negative Global Warming Potential and can save considerable amounts of CO2.
"The results show emphatically that in each of the scenarios Heriot Watt examined, wood, or wood-based materials offer longer life, better value and greater environmental benefits than PVCu," WWA chairman Sean Parnaby said.
"For the first time, we have solid, authoritative evidence to back up what we always believed was true – that wood is the best all-round window frame material.
"This research will challenge industry perceptions about the use of timber window frames, particularly around the use of aluminium-clad windows in large-scale projects in moderate to severe building conditions."
