Visible Light Transmission -
- Percentage of visible light transmitted through the glass. The higher this figure, the more daylight the glass allows to enter the building.

Insulating Index – U-Value Winter -
- The U-Value is a measure of the air to air heat transfer that occurs due to thermal conductance and the difference between indoor and outdoor temperatures. The lower the U-Value the better the insulation.

Using Air: With normal desiccated air occupying the cavity between the two sheets of glass.

Shading Index – Solar Heat Gain Coefficient (SHGC) -

- The proportion of directly transmitted and absorbed solar energy that enters into a buildings interior. It compares the performance of a particular glass type to that of no glass at all which is rated at 100% or 1. The lower the number is, the better the glass is at excluding direct solar radiation.

UV Transmission -

- The percentage of ultra violet light transmitted through the Insulated Glass Unit. The lower this figure the less UV transmission, hence a decreased tendency for fading to internal furnishings and fabrics.