Energy Efficiency

There are two main measures of energy performance which relate to windows and doors. The first one is known as a Window Energy Rating (or WER) and will be displayed on all windows and doors. It’s a familiar system, similar to that used on domestic appliances. Under current Building Regulations, windows and doors must be rated at Band ‘C’ or better. We’re pleased to say that all Spectus windows and doors can reach Band ‘A’ and that our Elite and Fully Reversible windows can achieve a Band ‘A+’ rating.

The second measure is known as a U-value, and this information should also be displayed on the same label. U-values measure thermal transmittance. The lower the value, the more effective an insulator the window is. However, very low U-values may mean that you do not gain as much warmth from the sun via passive solar gain.

Energy-efficient windows will reduce the costs of heating your home and your carbon footprint. But they also make your home a more comfortable place to live, eliminating drafts, cold spots and condensation, while also helping to insulate your home from external noise.