I've played around with paper printed scenery lots of times and have seen Dave Graffam's details paper model buildings on the net. I decided to try out some of his free pieces to see what they look like. Great stuff! To play at 15mm, you just set the printer to print at 50% scale and you have an instant 15mm building.
At first, after assembling this house, I thought, that is really, really small. However, when you take a photo with a figure and the building, it looked pretty good.
Anyway, here's a pic of a spearman and a small sample house. I printed on mat photo paper so it wouldn't be shiny.