Thanks!
Yeah, since the house is in 5 different parts, some of the faces are overlapping... That's what I was gonna do next, clean up the overlaps and model the bits of the interiors that you can see from the gianormous windows...

I was wondering; because I got weird results before, what does the function "detach component" do exactly? I detached some of the walls, but for one or 2 it didn't seem to work; when I was trying to insert new edge loops, the highlighted part seemed confined to the edge, not across the face, like it should be doing. Is there something I would need to know about residual geometry left by the "detachment"?