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Secondary glazing is experiencing a notable rise in popularity across the UK, as more homeowners seek out quieter, warmer homes without altering the historic character of their original windows, new data reveals.
The technique involves installing a slim internal pane alongside existing windows, providing better insulation and substantial noise reduction—without the need to remove or replace original frames. It’s especially appealing in period properties and listed homes where double glazing is often restricted.
“In the last couple of years, interest in secondary glazing has really taken off,” says Colin, founder of Colin’s Sash Windows, a nationwide supplier of timber sash windows and secondary glazing.
“It’s discreet, it’s effective, and it’s often half the cost of full window replacements.”
The scale of the issue is significant: approximately 80 million windows in UK homes still fall short of modern energy performance standards (GGF / British Glass, 2023). According to the English Housing Survey, one in ten homes still has single glazing. Single-glazed properties can lose as much as 20% of their heat through windows alone (Energy Saving Trust).
Secondary glazing is also proving a practical noise-reduction solution, capable of lowering outside sound levels by up to 80% (Colin’s Sash Windows). This makes it ideal for homes close to major roads, train lines, or airports—areas where local councils or airport schemes may offer support for such improvements.
Nearly 3 million homes across the UK still rely on single glazing, many of them character properties that can’t be easily altered.
Landlords are also taking notice, with energy efficiency and tenant satisfaction both key concerns.
“We often hear from landlords who are losing tenants because flats are too cold or too noisy,” Colin said. “Secondary glazing is a cost-effective way to fix both problems, protect rental income, and improve the property’s EPC rating.”
With updated regulations on energy performance expected soon, particularly for the rental sector, upgrading windows is fast becoming a necessity. Secondary glazing offers a simple path to raising EPC scores without requiring full-scale renovation work.
In London, demand has surged—especially in conservation areas where preserving window aesthetics is mandatory. Similarly, heritage-rich cities such as Bath, York, and Edinburgh are seeing increased uptake from property owners keen to enhance comfort while complying with planning restrictions.
“Secondary glazing used to be niche, but now it’s becoming mainstream. People want warmer, quieter homes and this is a smart, affordable way to get there,” Colin added.