Share 'extruding subdivision mesh'

Hi all, hi Giulio Extremely interesting your work on catmull-clark. (no more maya for a while) I wanted to do a very simple extrude, so I offseted the mesh, and build the walls. But using both Serpinski o frame, I'm having problems later with mesh union node. Mainly because I'm building the walls using surfaces and then rebuilding meshes!, which i guess is completely wrong, because it is losing…