Problem Extruding Curves in Direction of a Surface's Normal

Hi,

I am trying to achieve something that I think is pretty straightforward. This is part of my first project in Dynamo that aims at taking elevations of a building and “projecting” the curves onto a selected wall on revit, finding the centroid of the polycurves and placing window instances at the points. Everything works except for the direction of this “projection”, essentially I want to extrude the curves into the surface and use the intersection of the geometries on the wall in order to get the “projected” curves. What I am trying to achieve is what is shown on the picture with the two extruded shapes, however this was done by creating a vector from a line created by a start and end point. I want to be able to simply select a surface and flip the normal so that it extrudes the shapes just like in that image, without having to create a line for every wall. I have tried this but I am only managing to extrude one of the shapes. I have tried to flatten the vector output from the normal but it does not make a difference.

The vector from the line made from a start and end point works perfectly fine however. I have uploaded the images (I can only post one here), the Revit and Dynamo files to this google drive folder:
https://drive.google.com/folderview?id=0B8jARoP5hB9qdm94andTNEhRSWs&usp=sharing

Any thoughts on what might be the problem here? I have tried searching the forum on similar topics but could not find a solution. Any help would be greatly appreciated!

Best,

Danku

You’ll need to Loft
loft-20160720.dyn (10.3 KB)

Vikram_Subbaiah, sorry for the late reply. This worked great, thank you.