The Efficient Windows Collaborative

Single-Glazed, Clear Glass

This figure illustrates the performance of a typical single-glazed unit with clear glass. Relative to all other glazing options, single-glazed with clear glass allows the highest transfer of energy (i.e. heat loss or heat gain depending on local climate conditions) while permitting the highest daylight transmission.

Center of Glass Properties

Note: These values are for the center of glass only. They should only be used to compare the effect of different glazing types, not to compare total window products. Frame choice can drastically affect performance.

Whole Window Properties - Single-Glazed, Clear Glass


Frame	Metal Frame	Metal Frame with Thermal Break	Non-metal Frame	Non-metal Frame, Thermally Improved
U-Factor	≥1.00		0.71-0.99
SHGC	≥0.60		≥0.61
VT	≥0.60		≥0.60
Note: The thermal performance properties of specific glazings and frames can vary depending on product design and materials. The results presented here are averages. Consult specific manufacturers for NFRC rated U-factors and SHGCs for products of interest.

Single-glazed, Clear Glass | Single-glazed, Tinted Glass
Double-glazed, Clear Glass | Double-glazed, Tinted Glass | Double-glazed, High-performance Tinted Glass
Double-glazed, High-solar-gain Low-E Glass, Argon/Krypton Gas | Double-glazed, Moderate-solar-sain Low-E Glass, Argon/Krypton Gas | Double-glazed, Low-solar-gain Low-E Glass, Argon/Krypton Gas
Triple-glazed, High-solar-gain Low-E Glass, Argon/Krypton Gas | Triple-glazed, Low-Solar-Gain Low-E Glass, Argon/Krypton Gas