After building the cabin around the inner frame, I naturally had to fill in the gaps created by the frame. For this, I used 20-millimeter Armaflex, since the steel frame was also 20 millimeters high. It was quite simple, as Armaflex has a self-adhesive surface that adhered perfectly to the sheet metal of the sandwich panel. As you can see here, I also glued on 20-millimeter-thick wooden strips to provide supports and abutments for the cabinets.
