Energy Ratings

A window’s energy performance has traditionally been stated in terms of its U-value. However, some manufacturers may quote the centre pane U-value, whilst others quote the whole window U-value so therefore the performance of different products may not be readily comparable. Energy ratings are a new simple system of making accurate comparisons between suppliers.

Window Energy Ratings
  • Provide a simple easy method for comparison of the overall energy performance of windows
  • Measure U-value, solar gain and air leakage
  • Are classified in bands A-G where A is the best
  • Are customer friendly, consumers are familiar with the system used on electrical goods

In recent years, glass technology has made great strides. It began as a way to save energy bills. Now it is also about saving the planet.

McMullanODonnell’s PVCu windows use soft coat Low ’E’ glass as standard to ensure you have the level of comfort and peace of mind you want from your windows. As well as saving money through reduced fossil fuel consumption it makes the air we all breathe a little more breathable.