Glass is a good insulator but it would need to be very thick as a single pane in a window to have much effect. So rather than have thick glass in your windows it is better to have two panes of glass with an air or gas space between them.
The bigger the air space, the less heat is lost, up to an optimum of 20mm. All well designed and well fitted double glazed units significantly reduce the intrusion of unwanted noise.
By specifying glasses whose thickness differs by at least 30%, resonance effects are suppressed and the acoustic benefits are, therefore, maximised.
Ordinary glass - called Annealed or Float glass
This can either be Toughened, Laminated, Safety Wired Glass or Annealed glass with safety film applied to it. Safety glazing is mandatory for new installations within 800mm of the floor in windows and a legal requirement in doors and side panels. Glazing is marked in the corner with BS6206.
Laminated glass or Annealed glass with film applied to it. When security glass is installed you must ensure there is an emergency escape route in case of fire.
Low E glass
The glass must be used in a double glazed window so that the special reflective coating, which is always placed inside the cavity, is protected from any damage.
This can be Opaque, Patterned, Stained, Sandblasted or Etched.
In addition to the above standard glazing options there are a number of further choices to be considered. An advanced, high performance Low E Glass that allows a clearer view through the glass can be used; traditional Low E glass has a yellow tint.
Self-cleaning glass, Not 100% maintenance free but it will not need to be cleaned as frequently or thoroughly as conventional glass.
Argon Gas filled units are used to improve thermal and in some cases the acoustic properties of the double glazed unit.