A new study by Imperial College, London shows that windows manufactured to Wood Window Alliance standards give a service life of at least 60 years, even under low maintenance regimes.
The findings are good news for specifiers, particularly those working on local authority and public buildings, as they reflect the specifications required for new buildings, which themselves have a 60 year design life. And there’s better news still. The research shows that the service life can be extended to 80 years or beyond, by taking care when designing buildings to ensure windows enjoy more sheltered conditions and by undertaking enhanced maintenance regimes. Dr Richard Murphy, of Imperial College London, who undertook the research commented: ‘This research implies there is no reason why today’s Wood Window Alliance windows shouldn’t last as long as Edwardian and Victorian wood windows – a lifetime or beyond’. The research builds on previous extensive Life Cycle Assessment research by Imperial College carried out for Akzo Nobel in 2004 which showed that windows made to TWA (Timber Window Accreditation) Scheme standards gave a 40 year service life. This new study uses ISO 15686-8:2009 methodology to quantify the impact of the advances in design, manufacturing and coatings technology incorporated into today’s Wood Window Alliance windows.
Of these new exciting findings, John McCombes, Managing Director of Teknos UK and member of the Wood Window Alliance research sub-committee, said: ‘This research validates the huge advance in manufacturing standards over the last five years or so. We are seeing an increase in service life for Wood Window Alliance windows, which shows that they will actually last the design life of a building. This research is very good news indeed for the industry and for specifiers and consumers who can buy Alliance windows in the sure knowledge that, with appropriate maintenance, they will last a lifetime.’ The Imperial College data have been used to provide a new Whole Life Costing analysis. This work considers building life periods of 60, 80 and 100 years across a range of exposure conditions and maintenance regimes for two Wood Window Alliance A and C BFRC energy-rated windows and comparable PVC-U windows. The results show that the extended service life of a Wood Window Alliance window results in lower Whole Life Costs than the PVC-U windows at 60 years and beyond, with the Wood Window Alliance window costing from 2% to 7% less. These results complement Davis Langdon’s research on Embodied CO2e Impacts2, carried out in 2009, and updated in 2010, which confirms that the overall life cycle of a Wood Window Alliance frame is carbon negative and that each Wood Window Alliance window specified instead of a PVC-U window saves around 89kgs CO2e over the life of the window. In real terms, this means that if just half of the PVC-U windows fitted in the UK in 2008 had been Wood Window Alliance windows, there would have been a saving of over 300,000 tonnes CO2e.
Sean Parnaby, chairman of the Wood Window Alliance said: ‘The considerable body of research we have invested in demonstrates our commitment to providing specifiers and end-users with the evidence they need so that, when they specify Wood Window Alliance windows, they can be confident they are making the right environmental, performance and value choice.’
Despite carbon emissions from transport, production, maintenance and end of life, Wood Window Alliance manufacturers’ window frames are still carbon-negative because they are made from arguably the world’s most sustainable building material, wood sourced from sustainably managed forests. Forests absorb and retain more carbon from the atmosphere than they produce and sustainable management practices ensure this continues by replacing the trees which are felled, and so avoiding the damage caused by deforestation. The Wood Window Alliance unites wood window companies in a powerful marketing campaign, placing product quality, industry standards and sustainability at its core. All manufacturer members have to meet a set of quality, performance and sustainability criteria, with third-party accreditation. To find out more about this research please CLICK HERE
