[gallo26]

The yellow things only covered the braces for the walls so no one would trip over them. They weren't necessary on the outer edges near the air lock because the airlock was there as a support. You should go back to the 2007 and take a look at that. Maybe you'll find something.

And also being that this might be a render from the new Delta field we've seen pictures of, it might need that extra support on the edges.

Refer to this http://www.chiefdelphi.com/media/photos/34329 As it were taken of the Delta field, where you can clearly see the support necessary on the outside by the airlock. The yellow things were not present.