01 / Glazing Configuration
SHGC = proportion of solar heat transmitted. Clear glass ~0.76. Low-E ~0.55–0.65.
Standard reference values (vertical glazing):
• Rsi = 0.13 m²·K/W (indoor surface, EN ISO 6946)
• Rse = 0.04 m²·K/W (outdoor surface)
• Glass conductivity: 1.0 W/m·K (soda-lime glass)
• Argon gap improves R-value ~15% over air
• Low-E coating reduces emissivity from 0.84 to ~0.04–0.10
• Rsi = 0.13 m²·K/W (indoor surface, EN ISO 6946)
• Rse = 0.04 m²·K/W (outdoor surface)
• Glass conductivity: 1.0 W/m·K (soda-lime glass)
• Argon gap improves R-value ~15% over air
• Low-E coating reduces emissivity from 0.84 to ~0.04–0.10
02 / Result
Select a glazing configuration to calculate
Full assembly comparison — typical U-values
| Assembly | U-value (W/m²K) | R-value (m²K/W) | Rating |
|---|
AS/NZS 4663 / EN673 — scope and limitations. U-values are calculated for the centre of glass (Ug) using the standard EN673 method. Whole-window Uw includes frame and edge effects and is typically 10–30% higher than Ug. These are theoretical values at standard conditions (0°C outdoor, 20°C indoor, no solar radiation). Actual performance varies with humidity, altitude, and installation quality. For H1 compliance, use NZS 4214 thermal values or verified WEERS data from glazing manufacturers. Always use manufacturer-tested values from the NZ Window Association WEERS database for H1 building consent applications.
Reference: Preset Configurations (EN673 / AS/NZS 4663)
Values are centre-of-glass (Ug) at standard conditions. SHGC values for standard solar orientation. For H1, use verified manufacturer WEERS data.
| Configuration | Ug (W/m²K) | R (m²K/W) | SHGC | Rated |
|---|---|---|---|---|
| Single — Clear 4mm | 5.75 | 0.17 | 0.76 | |
| Double — Clear Air 4/12/4 | 2.80 | 0.36 | 0.72 | |
| Double — Low-E Air 4/12/4 | 1.50 | 0.67 | 0.62 | |
| Double — Low-E Argon 4/12/4 | 1.10 | 0.91 | 0.62 | |
| Double — Low-E Argon Warm Edge 4/12/4 | 1.00 | 1.00 | 0.62 | |
| Triple — Low-E Argon 4/12/4/12/4 | 0.60 | 1.67 | 0.50 | |
| Triple — Low-E Krypton 4/6/4/6/4 | 0.50 | 2.00 | 0.50 |
Ratings per WER system: A (<0.85), B (0.85–1.24), C (1.25–1.99), D (≥2.0) W/m²K. Low-E emissivity ~0.10 hard coat, ~0.04 soft coat.