Triple glazed timber windows are our most-specified glass configuration, with double and quadruple glazing available where different U-values are required. AGC and Saint-Gobain low-E glass, argon or krypton fill, warm-edge spacers. KIWA-tested. Whole-window U-values 1.0 to 0.6 W/m²·K, suitable up to Passive House targets.
Click on a glazing type to see full specifications. All data from independent KIWA and AGC laboratory testing.
Standard
Two panes of glass. ECO 68 profile. Cost-effective for mild climates.
Most Popular
Three panes with Low-E coatings and Argon gas. ECO 92 profile.
Passive House
Four panes, Ug 0.6. The highest thermal performance available.
| Parameter | Value |
|---|---|
| Glass layers | 2 |
| Glass U-value (Ug) | 1.0 W/m²K |
| Whole window Uw | 1.0 to 1.3 W/m²K |
| Sound reduction | 32 dB |
| Profile | ECO 68 (68 mm) |
| Gas fill | Argon 90% |
| Coatings | Low-E on surface 3 |
Suitable for renovations and projects in mild climates. Available on tilt and turn windows (ECO 68 profile).
| Parameter | Value |
|---|---|
| Glass layers | 3 |
| Configuration | 4mm Planibel Low-E + 16mm Argon + 4mm Clear + 16mm Argon + 4mm Low-E |
| Glass U-value (Ug) | 0.6 W/m²K |
| Whole window Uw | 0.78 W/m²K (ECO 92) |
| Light transmittance | 63% |
| Solar factor | 44 |
| Sound reduction | 32 dB (Rw) |
| Profile | ECO 92 (92 mm) |
| Gas fill | Argon 90% |
| Glass supplier | AGC (Planibel) |
| Standard | EN 410, EN 673, ISO 9050 |
Data from AGC YourGlass certification. Standard for all alu-clad windows, sliding doors, and ECO 92 tilt and turn windows.
| Parameter | Value |
|---|---|
| Glass layers | 4 (with PVB interlayers) |
| Configuration | Guardian ExtraClear + ClimaGuard Premium2 T, dual Argon gaps |
| Glass U-value (Ug) | 0.6 W/m²K |
| Whole window Uw | 0.6 W/m²K (PASSIVE 115) |
| Light transmittance | 48.4% |
| Solar factor | 25.8 |
| Sound reduction | 40 dB (Rw) |
| Total unit thickness | 49.5 mm |
| Unit weight | 49.61 kg/m² |
| Profile | PASSIVE 115 (115 mm) |
| Gas fill | 10% Air, 90% Argon |
| Glass supplier | Guardian |
| Certified by | KIWA (MD-14/477/GL) |
KIWA-certified performance data. Meets Passive House requirements. See Quadruple Glazed Timber Windows for full product details.
| Parameter | Double | Triple | Quadruple |
|---|---|---|---|
| Ug (glass only) | 1.0 | 0.6 | 0.6 |
| Uw (whole window) | 1.0-1.3 | 0.78 | 0.6 |
| Sound (dB) | 32 | 32 | 40 |
| Light (%) | 72 | 63 | 48 |
| Solar factor | 55 | 44 | 26 |
| Profile | ECO 68 | ECO 92 | PASSIVE 115 |
| Passive House | No | No | Yes |
Beyond standard low-E coatings, our triple glazed timber windows accept laminated safety, acoustic, fire-rated and solar-control glass from Saint-Gobain and AGC. Specify per-unit per project.
Reflects heat back into the room in winter, blocks solar heat in summer. Applied on interior or exterior glass surfaces. Standard on all triple and quadruple units.
PVB interlayer holds glass together if broken. Required for overhead glazing and high-risk areas. Available from inside, outside, or both sides.
Acoustic glass configuration achieving up to 46 dB sound reduction (Legno Comfort Silence). For properties near roads, airports, or railways.
Interlayers that foam and opacify when exposed to fire. Provides EI-30, EI-45 and EI-60 rated protection. Looks identical to standard glass.
Reduces solar heat gain while maintaining natural light. Ideal for south-facing windows and warm climates. ClimaGuard coatings from Guardian.
Integrated blinds sealed inside the glass unit. No cleaning, no damage, no dust. Operated by cord or magnetically. Available on all glazing levels.
Four styles of decorative bars to match any architectural period. From traditional cottage to clean contemporary.
Bars glued onto the glass surface from both sides. Cost-effective traditional look.
Bars applied on exterior side with spacers between panes. Deeper shadow lines.
Built into the frame structure. True divided light for heritage and period properties.
Bars sealed inside the glass unit. Clean exterior surface, easy maintenance.
Select your profile and glazing to see the whole window U-value (Uw).
Our team will recommend the right glazing based on your climate, building regulations, and energy targets.
See our Window Profiles page for detailed frame specifications.
