Need curves on the inner side of the surface to create floor

Not sure what you are after here, can you elaborate some? Also post the image of the full graph using the export canvas as image button (camera button in the top right of Dynamo) while zoomed in at this level so we have some more context.

This is the surface after intersecting my columns and beams… Im trying to get inner side of the curves so that i can make floor

Maybe this post can help?

Try making a solid instead of a surface, and intersect that with your unioned solid from the rest. Get the surfaces with a normal that has a z component of 1 and those parameter curves are your floor outlines.

ok I’ll try that
Can you suggest me the node for achieving those surfaces and those curves ?

He is using room boundaries command. I don’t have that data with me.

Maybe if you use the Group Curves node from Archi-lab. Then make (overlapping) surfaces from the grouped curves. And then join them with solid by union.
Then obtain the perimeter curve of that surface. That should be the outline of your floor.

The surfaces can be pulled from the solid after you subtract the beams/whatnot by using a Geometry.Explode node.

The curves can be pulled using the same, or a Surface.PerimeterCurves node.

Thanks will try