What is the difference between vacuum glazing, triple-pane glass, and double glazing?

What is the difference between vacuum glazing, triple-pane glass, and triple glazing?

Vacuum glazing insulates better than triple-pane glass and double glazing, even though it is much thinner. As a result, it almost always fits into your existing window frame. The difference lies in the air space. Double glazing and triple-pane glass have air or gas between the glass panes. With vacuum glazing, such as BENGglas, the cavity is completely evacuated. This allows you to achieve performance levels that cannot be attained with standard insulating glass.

1. Insulation Value: Vacuum glazing provides the best insulation
BENGglas insulates twice as well as triple-pane glass and more than three times as well as double glazing. You lose less heat, save on your energy bill, and enjoy greater comfort in your home.

  • BENGglas: U-value starting at 0.35
  • Triple-pane glass: U-value 0.70
  • Double glazing: U-value 1.10

2. Thickness: fits into your existing window frame
For double glazing and triple glazing, window frames often need to be modified or replaced. With BENGglas, you can keep your existing window frames and preserve the appearance of your building. This is ideal for historic buildings and character homes.

  • BENGglas: starting at 6.7 mm
  • Double glazing: approx. 21 mm
  • Triple-pane glass: approx. 38 mm

3. Light transmittance (LTA): more daylight
Because BENGglas is so thin, the glass remains clear. Despite its very low U-value, it lets in more daylight than triple-pane glass. Variants are also available in extra-clear glass and solar control glass.

  • BENGglas: more than 83%
  • Double glazing: more than 80%
  • Triple-pane glass: more than 65%

4. Stable in sloped and horizontal installations
With gas-filled insulating glass , the insulation performance deteriorates significantly when the glass is installed at an angle or horizontally, such as in a skylight or a sunroom. Vacuum glazing contains no gas that can circulate, so the insulation performance remains consistent at any angle.

  • BENGglas: remains stable
  • Triple-pane glass: up to 40% less insulation
  • Double glazing: up to 60% less insulation

5. Sound insulation: low frequencies are also well dampened
BENGglas dampens sound better, especially low frequencies such as traffic and bass. When corrected for low-frequency noise, BENGglas achieves 33–34 dB, while double glazing and triple glazing achieve approximately 27–31 dB.

  • BENGglas: 36 dB (−2; −3). Laminated up to 39 dB; with acoustic film up to 41 dB
  • Triple-pane glass: 33 dB (−2; −6)
  • Double glazing: 31 dB (−1; −4)

6. Lifespan: no decline in insulation performance
With double glazing and triple-pane glass, the gas slowly leaks out, causing the U-value to deteriorate over time. A vacuum cannot leak out.

  • BENGglas: stable for up to 50 years
  • Triple-pane glass: ± 30 years, with gradual decline
  • Double glazing: 20–25 years, with gradual decline

Curious about how much vacuum glazing would cost for your home?
Request a quote now.

Will I be eligible for a subsidy for insulating glass in 2026?

In the Netherlands, through the ISDE program (for a minimum of 3 m² and often combined with a second insulation measure). In Flanders, through Mijn VerbouwPremie (€64/m² for income categories 3 and 4). See the subsidies section for amounts and conditions.

When should I replace insulating glass?

If there is condensation or moisture between the panes, the edge seal is leaking and the glass is no longer insulating properly. Standard insulating glass lasts 20–30 years. Even if you still have single-pane or old double-pane glass, replacing it will immediately result in savings and greater comfort.

How do I know if I have single-pane, double glazing, or triple glazing?

Hold a lighter up to the window and count the reflections. Two flames: single-pane glass. Four identical flames: older double-pane glass. Four flames, one of which is a different color: double glazing (due to the coating). The type is also often stamped on the spacer.

How much does insulating glass cost per square meter?

Double glazing costs about €240 per m² installed, while triple-pane glass costs €270. If they don’t fit in your window frames, new frames will be required at an average cost of €750 per m². BENGglas vacuum glazing costs €350–400 per m² installed. Since it fits into your existing window frame, you won’t have to pay for new frames. Request a quote for an exact price.

Will insulating glass fit in my existing window frame?

That depends on the thickness of the glass and the rebate of your window frame—the groove where the glass sits. Double glazing is approximately 21 mm thick, while triple glazing is 36–38 mm thick. Window frames designed for single-pane glass are often too narrow for these thicker panes, which means new frames are needed. BENGglas® vacuum glazing is available starting at 6.7 mm and therefore almost always fits into your existing wooden or aluminum window frames. If necessary, the glass can be thickened or laminated to ensure it fits into any profile.