Union all Polysurfaces that are in a single list?

Hello all, I am super new to dynamo, but I am wondering if it is possible to do a boolean union operation on a list of poly surfaces. the Union module looks like it needs two inputs, but all my inputs are compiled. (Example, I am importing all exterior walls and want Union them to be one continuous shell) I thought about splitting the list into two, but the items in list 1 union only with items in list 2. List 1 items will not union with other list 1 items. Any advice?

I am not sure to have understood the problem. Maybe an image can help.


  • if you are want to create a PolySurface from a list of surfaces the node to use is PolySurface.ByJoinedSurfaces
  • If you want to create a solid the node is Solid.ByUnion

they both take as single input a list of elements.