Based on my experiences building terrain for the Grey City campaign, and inspired by the industrial game mat and ikubes from TopoSolitario, I decided to try my hand at building some modular terrain tiles and flat-folding buildings. I created them in Inkscape, using layers to organize the different layout and texture options. Here are the first few test prints:
this thread on the Cardboard Warriors forum.
UPDATE: after thinking about it, I noticed that swapping the side tabs around makes the building more stable and less likely to open up, so I made those changes. Here's a picture with the second building -- the research laboratory -- and some extras.