One problem I ran into, at least a couple builds ago, was that I could only place windows so that the open back side of it was against blocks and so useless as a window, instead of on/in a hole for a window. So I had to design another “building” just of slabs behind the window, switch into the furniture placing mode to attach my window to the “building”, and then erase the rest of that “building” before hitting “Build!” just so that they’d place the windows in the right place.