Many moons ago, TSR / Wizards of the Coast released a series of paper buildings for use in D&D games. They’re now available free for the downloading. Any medieval / fantasy wargamer will find these useful. I think they’ve really stood the test of time.
Paper Models
Japanese Tori Paper Model
Here’s a paper model of a Tori — the traditional Japanese gateway. You should be able to scale the model with software and your printer to fit your needs.
Paper Robot Model
What you really need is a giant robot to menace the heroes in your miniature wargames. You can get a nice paper model of a killer robot at Ravensblight.
Urban Gunstore Paper Model
Here’s a paper model of an urban gunstore. It would be useful in any number of modern urban warfare games.
Urban Auto Electronics Shop Paper Model
This paper model is an appropriately grungy model of an auto electronics store.