We note the debate around the replacement of windows at the Grade II-listed 17 St Peter Street and agree with the judgement made by the conservation office, Catherine Marlow, that “the materials proposed [uPVC] are considered to be lacking in detailing and craftsmanship and will not preserve nor enhance the conservation area. Other alternative materials are available that would be less harmful to the building and conservation area, and therefore the justification for using uPVC as a product is insufficient.”
The suggestion that new, improved, uPVC windows cannot be distinguished from timber is misleading. While they may be superficially similar to timber, they cannot be seen as ‘sympathetic replacements’ – the mass-produced sections cannot accurately match historic detail; the PVC-u material goes against the integrity of the original material; it cannot be redecorated or repaired easily; and we don’t know how well the material will age.
Have a look at these two reports, which shed light on the importance of using timber, rather than uPVC.
The first, compiled by the Alliance for Sustainable Building Products earlier in the year, reviews the evidence on the toxicity of PVC-u and the broader issues of its sustainability.
The second, published by the WWA, brings the WWF report Window of opportunity. The environmental benefits of specifying timber frames first published in 2005, up to date by reviewing the latest evidence on the lifecycle and environmental performance of wood versus PVC-u windows.
We believe authentic materials and authentic detailing are crucial to achieving sympathetic replacement windows in period buildings. We also believe we should be using responsible materials that have the lowest impact on the environment.