It is important to ensure that heat is not lost from the interior of a building through its windows. Efficient glass reduces energy costs, makes homes more comfortable and helps to reduce the carbon emissions that damage the Earth's atmosphere. The NSG Group is at the forefront of developing glass products that achieve this.

The efficiency of a window at preventing heat loss can be assessed by looking at its Ug-value. However, this does not take into account heat coming in from the sun. Solar energy improves the overall benefit provided by the window.

The type of glass used in the insulating glass units in energy-efficient windows is generally known as 'low emissivity' or 'low-e' glass. The improvement over ordinary glass is generally achieved by applying a fine coating to the glass. One well-known and trusted low-e product is Pilkington K Glass™. However, other products are available with a better Ug value, such as our own Pilkington Optitherm™.