I'm building a base and made the back corners of the base into two cuved foundations next to each other, so its fine when i build the roofs on the second story, i have to make two circle-rooms that lap over each other like a venn-diagram, which i figure that would be the problem but no, its just that one side of the venn-diagram doesnt clip well with the straight walls when i place the wall of the room on the same foundation as a straight wall,as they break the straight wall, but the exact oppisite side of the venn-diagram rooms, work perfectly fine, and do not break the straight wall.