Issue 41 Spring web - Flipbook - Page 53
The role of secondary
glazing in heritage and
ecclesiastical sector
With a UK-wide commitment to net zero by 2050, and approximately 5.4million traditional buildings
in England alone, there is a lot of work needed to upgrade both the building fabric and its fittings.
Replacing existing windows is not always desirable nor
permissible in the heritage and ecclesiastical sector, so
secondary glazing can be a very sustainable product
choice.
Long-lasting
Single glass does not degrade or fail, and treated
aluminium doesn’t corrode. So the life expectancy of
properly maintained secondary glazing can be substantial.
Protected from the main elements and not limited by
potential failure of sealed units, the life expectancy of
secondary glazing could easily exceed that of modern
replacement windows.
Retaining embodied carbon
There is no need to remove existing windows, meaning
the embodied carbon is retained and there is no waste
going to recycling or landfill. This is subject to frames
being in good order or repairable but many period
buildings have sound windows.
Thermally efficient
An independent, correctly installed and sealed secondary
window frame will minimise air leakage. It also ‘traps’ an
insulating layer of air that can reduce heat loss by 50-75%,
depending on the glass specification, with increased UValues and improved EPC and BREEAM ratings.
Easily reversible
Most Listed buildings cannot replace their existing single
glazed windows so, subject to listed building consents,
secondary glazing offers an excellent solution as Heritage
bodies accept it as a reversible adaptation.
Above, bespoke solutions for arched windows
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Conservation & Heritage Journal
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