See the difference

inside out


Windows aren’t just part of your home’s framework. They can add light and life, warmth and beauty.

That’s why choosing the right glass is so important.

Get to know your glass

The thermal resistance of the total window system (including glass, spacer and joinery type). The higher the R-value, the less heat that is lost through the system and the better the insulation.

Visible light transmission 
The percentage of visible light transmitted through the glass.
The higher the VLT, the more natural light enters the room.

Low-emissivity (low-e) glass
An almost invisible coating lets light and energy into your home and reflects heat back indoors, forming a shield against the cold. In warmer climates low-e glass can be used to keep heat out.

Shading co-efficient
The ratio of total solar heat gain through a particular glass type compared to the total heat gain through 3mm clear glass. The lower the shading co-efficient, the more the glass restricts the transfer of solar heat.

A noble gas used inside a double or triple glazed unit. It restricts the transfer of heat and provides greater insulation.