The Building Research Establishment (BRE) Green Guide to Specification, the best respected arbiter of the environmental credentials of building products in the UK, now recognises windows made to Wood Window Alliance specifications as a distinct standard.
Furthermore, it gives WWA windows the highest ratings in each category entered, giving customers the reassurance that whatever window they buy within the scheme will have the best environmental credentials. It also gives specifiers confidence that just by choosing windows from a WWA member, they will be bette able to meet BREEAM and other sustainability standards.
All WWA-standard timber windows are rated A+.
All WWA aluminium-clad timber windows with a translucent internal finish are rated A+.
All WWA aluminium-clad timber windows with a translucent internal finish are rated A.
These ratings, and the recognition that WWA membership criteria set a discrete standard, are further evidence of the environmental-friendliness and sustainability of wood in general and WWA members' products in particular. They follow the study undertaken by Dr Gill Menzies of Heriot Watt University, Edinburgh that concluded all WWA standard windows, whether timber, modified timber (e.g. Accoya) or aluminium-clad timber had significantly lower environmental impacts than equivalent PVC-u windows.
This is particularly true of Global Warming Potential (or CO2e emissions), where she shows that choosing a wood window instead of an equivalent PVC-u window saves around 160kg CO2e over a 60 year life. So a house with 10 windows could save over one a half tonnes of CO2e over 60 years just by having wood windows.
You can see Dr Menzies's presentation of her findings here.