We were able to give a 5 inch airgap to the back of the exterior double-glazed windows, and the secondary frame and panes are not in the least obvious. We'll be ordering from you for the other two windows on the road side of the house very soon. We have a suite of CPD options covering RIBA Core Curriculum. With the UK’s commitment to reach net zero by 2050, our passion for creating bespoke sustainable solutions for our customers has never been greater.(Image: https://adawindows.com/wp-content/uploads/2023/10/WhatsApp-Image-2023-03-17-at-15.46.02.jpeg) Our products help raise energy efficiency of buildings and their lasting sustainability.external site Historic England has reported that heat losses by conduction and radiation through a window can be reduced by over 60% by installing secondary glazing with Low-E glass facing externally.