ngon panelling to extruded solids

Hi, 

I want to transform any panel extrusions to solids and group them according to their volume or id. However, extruded planes on given surface are seperated and I do not know how to combine them in a closed solid-block. 

I have implemented a script created by Ngon but other panelling options or logic to create solids arranged on surface are also appreciated. 

I will try also turtle.

Thanks in advance.