Call NowYour Guide to Double Glazing Glass Types
Choosing the right double glazed glass to upgrade your windows is just as important as choosing the right installer. At RetroFit Double Glaze, we partner exclusively with Australia’s leading glass manufacturers Glassworks and Viridian Glass to provide precision-cut, high performance double glazed units
Each home is unique and we offer tailored double glazing solutions including improving thermal performance, boosting noise reduction and improving in-home comfort for heritage and period style homes.
LightBridge™ / Optitherm™ Our Most Popular Unit
Best for: Homeowners who want outstanding thermal performance and value. Our recommended choice for most Melbourne homes.
This is our best-selling unit and for good reason. LightBridge/Optitherm combines toughened safety glass, argon gas fill, and a Low-E coating to deliver thermal performance that rivals triple glazing at a fraction of the cost.
How it works: Low-Emissivity (Low-E) coating is a microscopically thin metallic layer applied to the glass surface. It reflects radiant heat back into the room in winter and blocks solar heat gain in summer, dramatically improving the unit's insulating performance.
Key specs:
U-value: 1.4 thermal performance rating (SHGC: 0.59)
Glass: Toughened 4mm + argon gap
Low-E coating
Grade A Safety Glass
Australian-made
10-year warranty
LightBridge Next™ / Optitherm Hush™ Maximum Comfort
Best for: Homes in noisy locations: busy roads, flight paths, near trams or trainlines or anywhere acoustic performance is a priority alongside thermal comfort.
This unit builds on everything that makes LightBridge/Optitherm so effective, adding VLam Hush laminated glass for best-in-class noise reduction. The laminated layer also provides exceptional UV protection and added security as laminated glass holds together on impact rather than shattering.
How it works: One pane is replaced with a 6.5mm VLam Hush acoustic laminate with a specialist acoustic interlayer. Combined with the argon gap, Low-E coating, and thermal spacer, this unit addresses heat, noise, UV, and security in a single unit.
Key specs:
U-value: 1.4 thermal performance rating (SHGC: 0.54, VLT 79))
Glass: 6.5mm VLam Hush + argon gap + toughened 4mm
Weighted Sound Reduction Index: Rw 38 for 6mm (best in class for double glazing)
UV transmittance: <1%
Low-E coating
Thermal spacer
Grade A Safety Glass
Australian-made
10-year warranty
Vacuum Insulated Glass (VIG) Next-Generation Performance
Best for: Heritage windows, maximum thermal performance, or any situation where a slim glass profile is essential.
Vacuum Insulated Glass represents the cutting edge of double glazing technology. Supplied by LandVac who are considered pioneers in the VIG space, this unit offers a level of thermal performance that surpasses both standard double and triple glazing, in a profile just 8.3mm thick.
How it works: Rather than an argon-filled gap, the two glass panes are separated by a near-perfect vacuum just 0.3mm wide, sealed with a titanium edge seal. A vacuum eliminates almost all conductive and convective heat transfer, making it the most thermally efficient double glazed unit available.
The extremely slim profile makes it ideal for heritage and period windows where thicker units cannot be accommodated.
Key specs:
U-value: 0.4 thermal performance rating (SHGC: 0.58, VLT: 80)
Glass: Toughened 4mm + 0.3mm vacuum gap
Total thickness: just 8.3mm
Low-E coating
Titanium edge seal
Grade A Safety Glass
15-year warranty
What Double Glazed Glass is Best for My Home?
Not sure what to choose? Here's a quick summary:
| LightBridge™ / Optitherm™ | LightBridge Next™ / Optitherm Hush™ | VIG | |
| Thermal Performance (U-value) | 1.4 | 1.4 | 0.4 |
| Noise Reduction | Good | Best in Class | Good |
| Heritage / Slim Profile | ✓ | — | ✓✓ (8.3mm) |
| UV Protection | Standard | <1% UV trans | Standard |
| Safety Glass | ✓ | ✓ | ✓ |
| Warranty | 10 years | 10 years | 15 years |
High Performance Australian-Made Double Glazed Glass.
All of our standard double glazed units are manufactured in Australia by Glassworks and Viridian Glass, Australia's largest glass processors and are custom-fabricated to seamlessly fit your exact window dimensions.
Our VIG units are supplied by LandVac, global leaders in vacuum glazing technology. Every unit is backed by our industry-leading warranty and our best price guarantee.