Ugly UV unwarpping in a simple case. What I'm doing wrong? I'm trying to unwrap a very simple model of a building. It unwraps fine except for the foundation of the building, where the angles between the edges are not kept.(screenshots below).



Why does Blednder fail in such a simple situation? And how to prevent this ugly unwraping?

The.blend file is here.
Thanks in advance.
Reselect all your faces and try Smart Uv Project