Energy Efficient Windows


Windows are designed to let in light, while blocking air and objects from entering the house. In addition, windows provide some insulation, but not much. They are only a few millimetres thick, and heat can easily flow through them, making it more expensive to heat and cool your house. Double glazed windows are designed to let light through while blocking the movement of heat, turning your windows into good insulators and are more energy efficient windows.

Evolution supply both double and triple glazed energy efficient windows which carry a minimum A+ Rating as standard, which will keep your heating bills low and help conserve the heat produced in your home. Our windows have one of the highest energy ratings and U values in the industry, so your new energy efficient windows will not only be an attractive addition to your home, but a wise investment.


The BSI Energy Rating system is the UK’s national system for rating the energy efficiency of windows and is recognised within the Building Regulations as a method to show compliance. BSI window energy rating uses a traffic-light style A-E ratings guide similar to that used on white goods (such as fridges, freezers, washing machines etc). As well as taking U values into consideration, the BSI energy ratings also take into account the nominal solar heat gain provided by windows.

Window Energy Ratings determine how well a window will perform the functions of helping you contain and conserve heat within your building in the winter. Both A+ rated as standard, the Storm and Flush window ranges take energy efficient windows to the highest level with double glazing to 28mm thickness.


U-Values measure how well heat is transferred by the entire energy efficient windows - the frame, sash and glass - either into or out of the building. U Values are measured in W/m2K, the lower the U-Value number, the better the window or door will keep heat inside a building on a cold day.

Both the Storm and Flush window ranges have a 1.3U value and is rated WER A+ as standard. By choosing any windows from the Evolution range you can be assured they will keep your home lovely and warm in winter, cool in the summer and your bills to a minimum, knowing you are not wasting or losing energy.

It has been shown that energy efficient windows will help to minimise heating costs when installed by skilled qualified professionals. Using Evolution will ensure that your windows will be a valuable asset to your home for many years to come.


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