Home windows and shading for energy efficiency

Last updated: 6 September 2022

Windows are a vital part of any home – they allow natural light into the home and provide views and fresh air. Well-planned and protected windows improve comfort year-round and reduce the need for heating in winter and cooling in summer, saving money and reducing emissions.

Watch our video – Energy Efficiency At Home: Windows – to learn more.

Energy efficient windows

A single pane of bare glass can gain or lose up to 10 times more heat than the same sized area of uninsulated wall. The style of window, the type of glazing, window coverings and external shading are ways that windows can be made to be more energy efficient.

Energy efficient windows and glass are designed to:


Windows consist of glazing and framing, and both contribute to the energy efficiency of the window. The energy efficiency of windows is measured by a rating called a U-value. The U-value measures the amount of heat passing through a window or other glazed unit in watts; the lower the U-value, the more energy efficient your window is.

Windows with low U-values are more effective at keeping out unwanted heat and cold, which improves your comfort levels and reduces your energy costs.

Logo for the Window Energy Rating Scheme

Window Energy Rating Scheme

The Window Energy Rating Scheme gives a star rating to a window's glazing and frame energy performance, making it easier to compare different windows and decide which is best for your needs.

Read more