
Wood windows have attracted some bad press in the past. But a revolution in technology and sustainability means that long held misconceptions are now obsolete.
To set the record straight the WWA has put together these simple myth busters which provide the facts about modern wood windows.
You have to cut down trees to make wood windows and this has a big impact on climate change from deforestation.
Fact
All WWA windows are made from sustainably sourced timber (FSC, PEFC, SFI or CSA) and carry full chain of custody certification. This means that the wood used is traceable from sustainable forests where more trees are replanted as they are harvested. In fact this is one of the reasons that a new Life Cycle Assessment (LCA) study by the consultants Davis Langdon shows that WWA standard windows are carbon negative, meaning that more CO2 is absorbed during a window’s life time than is released.
Wood windows did not score as highly as expected in the BRE Green Guide.
Fact
Domestic wood windows made to the standard required for membership of the WWA rate ‘A+’ in BRE’s Green Guide compared with ‘A’ for their nearest competitor material. These wood windows also have the highest score of all windows in the Green Guide by some distance on the crucial ‘Climate Change’ or ‘Global Warming Potential’ rating (the highest weighted factor).
Wood windows aren’t thermally efficient, so it is hard to achieve the goal of reducing energy usage.
Fact
Wood has very low thermal conductivity, which means it is a good insulator. But the energy efficiency of a window actually has little to do with the frame material and is mostly affected by the specification of the glazing unit, so well-designed windows have similar thermal efficiencies across the board.
All WWA windows are double or triple glazed and many members offer ‘A’, ‘B’ or ‘C’ BFRC energy ratings and U-values as low as 0.8 W/m2K.
More PVC windows are recycled than wood windows.
Fact
The window industry in general is making efforts to improve recycling. Although there are no specific figures for the number of recycled windows, the audited volume of recycled waste wood in 2007 was 2 million tonnes and the quantities for PVC recycling were 42,122 tonnes in 2007 and 42,730 tonnes in 2008 (source: Vinyl 2010 progress report 2009). Wood is also increasingly recovered as biomass energy, providing an additional and sustainable end-of-life option.
Wood windows rot.
Fact
WWA windows carry the best warranties in the sector, typically a 30 year warranty on the frame and 8 years on the paint – that’s better than a Mercedes or BMW motor car.
The BRE estimates a 35 year minimum service life for windows made to the standard of WWA windows. However, because wood windows can be maintained and repainted, WWA members believe there is every reason for their windows to last a lifetime, and there is plenty of evidence that well-maintained, good quality timber windows can last a century or more.
Wood windows use chemical treatments that are bad for the environment.
Fact
Water, rather than solvent, based treatments and paint systems are now used in modern window manufacturing and are classified as non-hazardous. The environmental impacts of the preservatives and coatings are covered within BRE’s Life Cycle Assessment which gives WWA standard windows the highest overall rating.
If you want double-glazing you have to have PVC-U windows.
Fact
People assume double-glazed windows have to have PVC-U frames, but this couldn’t be further from the truth. In fact, all WWA windows are double or triple glazed, and the manufacturing process for wood windows makes them particularly suited to triple glazing.
Wood Window Alliance windows are the ‘green’ choice