02/06/2026
The earliest generations of double glazing were simply sealed units filled with air, providing a significant improvement over single glazing but offering relatively limited thermal performance by today's standards. As energy efficiency has become an increasingly important consideration for homeowners, window technology has evolved considerably.
Modern double-glazed units are commonly filled with argon gas, a safe, colourless and odourless noble gas that is around 34% less thermally conductive than air. Because argon is denser than air, it slows the transfer of heat through the glass unit, helping to keep homes warmer in winter, cooler in summer and reducing overall energy consumption.
As building regulations continue to tighten and homeowners seek ever-greater levels of thermal efficiency, triple glazing is expected to become increasingly popular. Combined with advanced glass coatings and argon-filled cavities, today's glazing solutions offer performance levels that would have been unimaginable when the first air-filled double-glazed windows were introduced.
