Ha! I just came across this piece of text about the Barcelona Pavilion, which I wrote a post about not so long ago:
"In reality, the Barcelona Pavilion was a patch-up structure. Technically Mies was unable to erect the pavilion as a pure 'Dom-ino' structure; the eight cruciform columns alone could not support the roof and a number of extra columns had to be lodged in the double-skinned marble screens to help carry the load. But this makeshift structure did the job Mies asked of it and the plan remained inviolate. He pursued the idea in his model house at the Berlin Building Exhibition of 1931..."
- Frank Russell, ed. Mies van der Rohe: European Works. p20.
Assuming this piece of information is genuine, the walls of the pavilion are load bearing even if the concepts states they are not. Good old Mies was surely on the move in this case!
P.S. The dom-ino issue in the text refers to a concept of Le Corbusier where columns, free of facades and walls, carry a roof, basically the same as what Mies did.
[Posted by Hans Larsen]