With the Government placing sustainability at the heart of their ‘Build Back Better’ recovery strategy, timber is the obvious choice but can often be overlooked by when it comes to the specification of windows.
The substitution of steel and other high carbon construction materials with wood products is increasingly being cited as a way to help achieve the UK’s 2050 net zero target. The Committee on Climate Change most recently championed the use of wood in a letter to MHCLG – click here to read more.
As a trade alliance representing the wood window sector, we have commissioned a number of studies on the environmental credentials of window frames to help us understand how they compare with other materials. A ground-breaking study for us was ‘Whole Life Analysis of Timber, Modified Timber and Aluminium-Clad Timber Windows’ by Heriot Watt University.
Expected Service Life of Wood Windows
In this study Heriot Watt University looked at the Service Life Planning (SLP) and Whole Life Cost (WLC) of wood window frames compared with other types of materials. The specification they used was the standard set by the Wood Window Alliance (WWA).
The study found that these modern, factory finished wood window frames made from sustainably sourced timber had an expected service life between 56 to 65 years in average UK conditions. This is almost double that of PVCu window frames which were found to have an expected service life of between 26 to 35 years in the same average climate conditions.
Taking this expected service life into account, it was found that WWA wood window frames are carbon negative over their life cycle. In the the study, Heriot Watt University built on insight by Davis Langdon in 2010 and found that every wood window made to the WWA specification chosen instead of PVC-u saves around 160kgs CO2e across the service life. Planned maintenance prolongs the life of the window and its carbon store effect, reducing the impacts caused by new replacements. Click here to read the full report.
The WWA are now looking at investing in Environmental Performance Declarations to help specifiers in their consideration of the whole-life carbon assessment of products.
Find Out More
To find out more about the WWA specification and its associated environmental credentials, visit the Wood Window Alliance website – https://windows.bwf.org.uk/