Placing units without collision

Is there any way to place a building without collision, a la Starcraft X-Tra Editor's special mode? I'm making an advanced map and need some buildings to overlap each other or be on the sides of cliffs.. Any help?

you mean in world editor? or in game?

in we it's simple, you gotta play around with pathing, just set a doodad pathing in unit editing.. like barrel or something, it will let you overlap pretty well, but don't put none, it won't work.

in game maybe you can create a building, take out the collision with a trigger, and then move it to spot you need.

I believe you can find your answer here.