I am making a simple building in blender. The method I used is by extruding a cube bunch of time for rooms, and then deleting one of the faces so the model is hollow. Now I want to add depth to the walls of the model, but when I extrude the faces to add thickness the extrutions are hollow. What can I do to fix this problem?

Do you mean the upper faces are missing like in the attachment?
Easy. Using F you can make tris or quads (types of faces aka polygons) out of 3 or 4 vertices respectively. Using SHIFT + F you can fill a greater number of vertices with tris.
Good luck with your project!


In the first photo below is my current room. The second is after I try to extrude the ceiling, as you can see it is hollow. I tryed selecting all of the edges of the very bottom of the ceiling and making a face like you said, but I got an error saying: “No faces selected to make FGon”. What am I doing wrong?

Thanks for the help so far


That’s how extrusions work. I think it works in a way where it doesn’t try to leave non manifold edges. In an extrusion that simple I’d duplicate the ceiling and place the copy where you want the height then use remove doubles.

You’re in Face Select Mode - when you extrude that face you have additional verts that have to be accounted for when you extrude (because of hallways? doorways?) . Go in to Vertex Select Mode or Edge Select Mode and then extrude …
Although you should have lines across at that intersection on the floor too - that isn’t geometrically logical (in Blender’s modelling system anyway manifold edges are a no no) ???
Is you ceiling just one rectangle too ? If so how did you layout/make the floorplan ?
If going in the other select modes don’t help post some screenshots of your floor plan and a screenshot looking down at the ceiling before extruding .


Take a look at this thread, there is a good little tutorial regarding simple walls.


Best of Luck!!

You selected all the edges. If you were in vertex select mode, you’d see you have selected 8 vertices. Blender can only make faces of either 3 or 4 vertices. So you get an error message. To do it properly, go into edge select mode (or vertex select mode) and select two opposite edges. Then f will make a face between the two. You also appear to have created new faces at all the edges. Did you select everything and then do an extrude? You may want to do a “remove doubles” (w>>remove doubles) before you create any more faces.

Thanks for the help everyone, I have a much better idea of what I’m doing now.