I've of course tried to make it as a cube, as it would seem quite logical, but the problem is that when doing so, the walls are flat planes. I have then tried to extrude the faces of the walls to make them wider, but since extrude only moves the face, I'm not getting the desired effect of making the walls "thicker". I've also tried to extrude and then use "fill hole" but with no luck.
Thanks for your help
