Turn two planes into a volume I would like to turn two regular spaced grids (so same amount of vertices, spaced at regular intervals) into a volume in which the top plane becomes the top of the volume and the bottom plane the bottom of the volume. 



I've succesfully done this duplicating the two planes (save for later), then join the original two planes and then in edit-mode -> "Bridge faces". This would remove both planes and leave me with he outer band of the volume (see image)



I then placed the outer band between the previously duplicated planes. Job done.



But this is a bit of a pain in the neck because i would like to do this for a lot of sets of planes. And also do this with irregular spaced planes and regular spaced planes with a different extend.

Is there a method or workaround to do this more easily?
Bridge Edge Loops should work here. 


Join both planes into one object through Object > Join, Ctrl+J
Use edge selection and go Select > All by Trait > Non Manifold (to select the loops)
Then Edge > Bridge Edge Loops




Edit:
In your case, the mesh has two forgotten edges in one of it's corners (one on each plane). Just delete them an it will work no problem.
After all that you can recalculate normals so they're all pointing the right way