Double glazing windows are formed by using two panes of glass such that they have a buffer between them. The middle buffer is several millimetres thick, and acts as an insulating material. Usually, the middle buffer is air, but often a gas like argon is used instead. The important factor in the creation of middle buffer is to make it airtight, so that it can act as an effective insulator.

Depending on the types of panes used, the following are some of the types of double glazing windows:

• Clear Glass This type of glass is used when you wish to receive as much sunlight into your room as possible. Even as it increases interior lighting, double glazed windows made of clear glass can still prove better insulators than other types of single glazed windows.
• Gray-Tinted Glass these types of panes have a gray or bronze tint, which results in less loss of heat from your room. They also reduce the transmission of visible light when compared to clear glass.
• High-Performance Tinted Glass This type of glass is a midpoint between clear glass and gray-tint glass as far as its attributes with respect to transmission of visible light and insulation are concerned.
• Gas Fills when the space between the two panes is filled with gases such as Argon or Krypton to reduce heat loss, it is called gas filled double glazing.

Other types of double glazed windows include panes with low- remittance coatings, which are metal coatings done to increase insulation.