Converting building elements to a single mass

Hi Fellow Dynamo users,

I have a task where I need to get the boundary of the whole building, looking for the volume of an entire building, then the hard part is connecting all of the walls, roof, etc into a solid block, without a hollow interior.

I tried solid union node and getting the topology but how do a make a single solid combining all walls floors, foundation elements etc.

Is there a way to make it a reality, any leads to start would be great.

Solid.ByUnion node should do the trick. I recommend grabbing the rooms too.