Five times as strong as ordinary glass
Heat-treated glass is ordinary glass heated to 650°C and then rapidly cooled down. This makes the glass almost five times stronger than ordinary glass. The heat treatment also affects the shear pattern of the glass. When heat-treated glass is subjected to a heavy impact it breaks but shatters into small fragments, reducing the risk of serious cuts. Heat-treated glass is also highly heat resistant and able to withstand temperatures of up to 275°C. In very rare cases and under certain circumstances, tension in the glass may cause it to rupture.

Lets in light
Heat-treated glass does not affect external light or colours more than ordinary glass. Ordinary glass is slightly green, which is the colour that steals least light and gives least colour distortion – the colour rendering index is high.
Heat-treated glass can be combined with various types of functional glass such as coloured glass, UV protective glass or energy glass.

Better indoor climate with energy glass
Energy glass is ordinary, heat-treated glass with a selective low-emission coating on one side. The coating is extremely thin and transparent, causing the glass to reflect heat radiation back into the room. At the same time, it lets in solar energy and visible light. When the room heat is reflected back, thermal insulation improves considerably and the inner glass gets warmer.  The high surface temperature reduces or even eliminates cold down-draughts and cold radiation from the window surface, which helps improve the indoor climate. In terms of light inflow, the properties of energy glass are almost identical to those of ordinary glass.

From the left: Energy glass, standard glass.