I haven't seen any aside from what comes in the starter kit.
I never liked paper scenery, I have never been able to get it to look anywhere nearly as nice as it does on the websites. The cardstock wants to warp with glue of once glued the edges want to come apart. I can actually make my own foamcore or DIT foam buildings in about the same amount of time it takes to print, cut assemble, rip apart, reprint and give up on the cardstock buildings.