Yes it is. Whether you want to just replace one or two windows with a hup! wall or add hup! to existing walls to create a completely new look, hup! can easily cope. You can choose between having a cill between the dwarf wall and the hup! wall and having a different wall finishes on the hup! or you can choose the full cladding option where the wall finish can run the entire height of the building for a more premium look. hup! works on both 250mm and 300m walls -the width of the existing wall must be specified at the time of order. If Building Regulations are required, you will need to bring the entire wall to 0.18 UValue.