
Heat resistant glass is specially treated glass and it has a heat reflective coating on one side of the pane. The coating is very thin but will nevertheless give your conservatory windows a slight brown or grey tint to them. This special coating allows the sun's energy to pass through the glass from the outside while reducing heat and energy loss from inside your home. It is thus recommended to people who want some form of extra insulation in their conservatory.
There are two types of heat reflective glass. The first type of heat reflective glass is a sputtered or soft coat glass; in this type of heat reflective glass the coating is easily damaged by air or moisture. This type of glass does not work well in a single unit. This coating can only be used on the inner side of a double or triple glazed unit.
The second type of heat reflective glass is what is known as pyrolitic or hard-coat glass. This second type of glass does not have to be part of a double or triple glazed unit - on its own however it is not effective for keeping out the heat of the sun. Heat reflective glass is popular because on very bright days it will reduce the amount of glare in your conservatory - at the same time it will also let in sufficient light if it is a dull day.
Heat reflective glass does not provide this insulation by itself; in order to do that the glass has to be part of a double or triple glazed unit. If you have had to get planning permission for your conservatory then you may not be able to have heat reflective glass as most planning officers do not like the tint that it has.